Proteins and Amino Acids in Fine Particulate Matter in Rural


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Proteins and Amino Acids in Fine Particulate Matter in Rural Guangzhou, Southern China: Seasonal Cycles, Sources and Atmospheric Processes Tianli Song, Shan Wang, Yingyi Zhang, Junwei Song, Fobang Liu, Pingqing Fu, Manabu Shiraiwa, Zhiyong Xie, Dingli Yue, Liuju Zhong, Junyu Zheng, and Senchao Lai Environ. Sci. Technol., Just Accepted Manuscript • Publication Date (Web): 15 May 2017 Downloaded from http://pubs.acs.org on May 15, 2017

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Proteins and Amino Acids in Fine Particulate Matter in Rural

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Guangzhou, Southern China: Seasonal Cycles, Sources and

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Atmospheric Processes

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Tianli Song†,○, Shan Wang†,○, Yingyi Zhang*,†, Junwei Song†, Fobang Liu‡, Pingqing Fu§,

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Manabu Shiraiwaǁ, Zhiyong Xie , Dingli Yue∇, Liuju Zhong∇, Junyu Zheng†, Senchao

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Lai *,†



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Control, School of Environment and Energy, South China University of Technology,

Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution

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Guangzhou, China

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Germany

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§

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Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing,

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China

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ǁ

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Multiphase Chemistry Department, Max Planck Institute for Chemistry, Mainz,

State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric

Department of Chemistry, University of California, Irvine, CA, USA



Helmholtz-Zentrum Geesthacht, Centre for Materials and Coastal Research, Institute of

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Coastal Research, Geesthacht, Germany

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∇Guangdong

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Laboratory of Regional Air Quality Monitoring, Guangzhou, China

Environmental Monitoring Center, State Environmental Protection Key

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*Corresponding Author: phone: +86-135-7097-4216; e-mail: [email protected]

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phone: +86-156-9242-3889; e-mail: [email protected]

These authors contributed equally.

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ABSTRACT: Water-soluble proteinaceous matter including proteins and free amino

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acids (FAAs) as well as some other chemical components was analyzed in fine particulate

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matter (PM2.5) samples collected over a period of one year in rural Guangzhou. Annual

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averaged protein and total FAAs concentrations were 0.79 ± 0.47 µg m-3 and 0.13 ± 0.05

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µg m-3, accounting for 1.9 ± 0.7% and 0.3 ± 0.1% of PM2.5, respectively. Among FAAs,

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glycine was the most abundant species (19.9%), followed by valine (18.5%), methionine

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(16.1%) and phenylalanine (13.5%). Both proteins and FAAs exhibited distinct seasonal

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variations with higher concentrations in autumn and winter than those in spring and

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summer. Correlation analysis suggests that aerosol proteinaceous matter was mainly

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contributed by intensive agricultural activities, biomass burning and fugitive dust/soil

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resuspension. Significant correlations between proteins/FAAs and atmospheric oxidant

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(O3) indicate that proteins/FAAs may be involved in O3 related atmospheric processes.

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Our observation confirms that FAAs could be degraded from proteins under the influence

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of O3 and the stoichiometric coefficients of the reactions were estimated for FAAs and

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glycine. This finding provides a possible pathway for the production of aerosol FAAs in

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the atmosphere, which will improve the current understanding on atmospheric processes

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of proteinaceous matter.

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1. INTRODUCTION

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Proteinaceous matter is an important fraction of atmospheric aerosols, accounting for

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up to ~5% of urban particulate matter.1 There are two forms of proteinaceous matter in

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aerosols, namely free and combined amino acids (proteins and peptides). Due to their

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influences on hygroscopic growth, microstructural rearrangement and crystal/droplet

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properties, aerosol proteinaceous matter may act as ice nuclei (IN) and cloud

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condensation nuclei (CCN) to affect atmospheric radiation balance and climate.2,

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Proteinaceous matter can cause adverse health effects because of their allergenicity4, 5 and

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deleterious effects on human health especially with their post-translational modified

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forms.6-9 Besides, proteins and amino acids (AAs) are considered to be the major forms

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of organic nitrogen compounds in atmospheric aerosols, and contribute to the

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atmosphere-biosphere nutrient cycling and global nitrogen cycle.10, 11

3

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Water-soluble proteins in aerosols have been analyzed to evaluate the levels of

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biological particles in Mexico,12, 13 China,14 Ecuador,15 and the US.4, 16-20 As an important

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class of organic nitrogen and organic carbon compounds, free amino acids (FAAs) in

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aerosols have been investigated in different areas, including urban/suburban,21-25 rural,26,

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27

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proteins and FAAs simultaneously in atmospheric aerosols34 and little attention has been

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paid to the atmospheric processes of proteinaceous matter in aerosols.

marine11, 28-34 and even polar regions.35, 36 Till now, few studies have focused on both

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Previous studies also investigated the seasonal variations of proteins/FAAs in

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aerosols.14, 17, 19-21, 23, 25 It was observed that higher concentrations of proteins/FAAs in 5 ACS Paragon Plus Environment

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warm seasons (i.e., spring and summer) than those in cold seasons (i.e., autumn and

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winter) in Iowa,19 Arizona,20 North Carolina,17 and Roma,23 and in contrast,

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enhancements of proteins/FAAs were observed in cold seasons in China.14, 21,

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different seasonal patterns can be affected by different sources and, possibly,

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environmental behaviors in different regions. Primary biological aerosol particles are

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suggested as one of the major sources of aerosol proteinaceous matter in the

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atmosphere.10 Anthropogenic activities can also be the sources of aerosol proteinaceous

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matter, e.g., soil resuspension from traffic and construction, crop cultivation and biomass

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burning.4, 14 Mopper and Zika37 proposed that, in the atmosphere, degradation of high

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molecular weight (HMW) proteinaceous matter could be a source of low molecular

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weight (LMW) FAAs. Recently, the release of FAAs upon the oxidation of proteins and

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peptides with hydroxyl radicals (·OH) in aqueous phase has been observed in a

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laboratory study.38 However, the release of FAAs from HMW proteinaceous matter has

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not been observed in ambient environment.

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The

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As one of the most rapidly economic developing regions in China, the Pearl River

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Delta region (PRDR) is densely populated and economically developed, with high levels

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of particulate pollution as well as high levels of ozone (O3) and other pollutants.39

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Meanwhile, this region is of subtropical humid monsoonal climate40 and the condition is

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suitable for plants growing and proteinaceous matter releasing throughout the year. The

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region is ideal to reveal the atmospheric interaction between natural emissions and

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atmospheric pollutants, which is focused on in this study. 6 ACS Paragon Plus Environment

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Here, we present a one-year observation of both proteins and FAAs in fine particulate

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matter (PM2.5) at Tianhu, Guangzhou, a regional site of the PRDR. The objectives of this

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work are: (1) to measure the concentration levels and seasonal cycles of proteins and

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FAAs in PM2.5; (2) to investigate the sources of aerosol proteins and FAAs; (3) to

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understand the occurrence and atmospheric processes of aerosol proteinaceous matter in

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ambient environment, especially the release of FAAs upon the oxidation of proteins and

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peptides. The results may help to improve the current understanding of sources,

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atmospheric processes and fates of aerosol proteinaceous matter in the atmosphere.

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2. MATERIALS AND METHODS

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2.1 Sample Collection. PM2.5 samples were collected at Tianhu, Guangzhou (23.65 oN,

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113.63 oE, Figure S1) from March 2012 to February 2013. The sampling site is one of the

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national monitoring stations in the PRDR with continuous measurements of air pollutants

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(e.g., SOx, NOx, O3), which is ideal for observation of atmospheric processes.41, 42 Filter

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samples were collected every six days with a duration of 24 h on PTFE filters and

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prebaked quartz fiber filters (550 oC, 10 h) using a mini volume sampler (5 L min-1,

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Airmetrics, US) and a medium volume sampler (300 L min-1, Minye, China), respectively.

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A total of 52 PTFE filters and 51 quartz filter samples were obtained for proteinaceous

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matter and other chemical components analyses.

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2.2 Protein and Free Amino Acid Analyses. A part of each filter sample (~60 m3 of

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air) was ultrasonically extracted twice for 30 min in an ice bath with 6 mL and 4 mL of 7 ACS Paragon Plus Environment

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autoclaved Milli-Q water (18.2 MΩ cm). The extract solutions were combined and

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filtered through a syringe filter (0.45 µm cellulose acetate membrane, Thermo, US). The

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filtered extracts were lyophilized and redissolved in autoclaved Milli-Q water for the

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following protein and FAA analyses.

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An aliquot of 500 µL was taken for protein analysis with a bicinchoninic acid assay

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(BCA, Micro BCA Protein Assay Kit, Thermo, US).4, 6, 14, 19, 43 Before BCA analysis, the

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sample extract was subjected to size-exclusion column (PD MiniTrapTM G-25, GE

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Healthcare, US) to remove possible interfering substances including proteinaceous matter

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of molecular mass (MW) smaller than 5 kDa, such as FAAs and some peptides. Then the

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proteinaceous matter of the purified sample (MW > 5 kDa) was determined with BCA

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assay. The assay was performed in microwell plates (96 wells, Corning, US) and

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calibrated with aqueous standard solution of bovine serum albumin (BSA, in Assay Kit).

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The other aliquot (300 µL) of the redissolved sample were again lyophilized and

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redissolved with 100 µL of 0.1 N HCl for the FAA analysis. Free amino acids were

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determined by high-performance liquid chromatography (HPLC) with a pre-column

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derivatization using o-phthalaldehyde (OPA) and 9-fluorenylmethyl chloroformate

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(FMOC).44 The applied HPLC system (Agilent 1260, Germany) consists of a quaternary

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pump (G1311C), an auto-sampler (G1329B) and a fluorescence detector (G1321C, λex =

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330 nm and λem = 420 nm). Chromatographic separation of FAAs’ derivatives was

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performed with a Zorbax Eclipse-AAA column (4.6×150 mm, 5 µm) at 40 oC, and a

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typical chromatogram for AA standard solution is shown in Figure S2. 8 ACS Paragon Plus Environment

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As detailed in Table S1, the method detection limit (MDL, 3 s method, n = 5) for

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proteins was 1.08 µg mL-1 and the corresponding effective limit in the aerosol samples

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(EMDL) was 0.03 µg m-3, with a precision of ~2%. The MDLs of the investigated

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individual AAs (i.e., aspartic acid (Asp), glutamic acid (Glu), asparagine (Asn), serine

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(Ser), glutamine (Gln), histidine (His), glycine (Gly), threonine (Thr), arginine (Arg),

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alanine (Ala), tyrosine (Tyr), valine(Val), methionine (Met), tryptophane (Trp),

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phenylalanine (Phe), isoleucine (Ile), leucine (Leu) and lysine (Lys)) ranged from 0.04 µg

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mL-1 for Val to 1.98 µg mL-1 for Gln, and their EMDLs were from 6.9×10-4 to 0.03 µg

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m-3. The precisions of the investigated AAs were all less than 10%. Measurement results

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for field blank filter samples were below the MDLs. To test the recoveries of the

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extraction method, standard solutions (BSA and AAs) were spiked onto the blank filters.

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The recovery of BSA was 67.0%, and those of the individual AAs ranged from 62.6% for

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Met to 79.4% for Ser (Table S1). The lower recoveries than previous studies27, 45, 46 can

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be influenced by the high protein absorption of quartz fiber filters.

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2.3 Other Chemical Components Analyses. The mass concentrations of PM2.5 were

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determined by scaling the mass differences of PTFE filters before and after sample

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collection with an electronic microbalance (± 0.001 mg, Sartorius MC5, Germany) and

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the sample volumes (~7.2 m3). Elemental carbon (EC) and organic carbon (OC) were

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analyzed by an OC/EC analyzer (Sunset Laboratory, US) using the thermo-optical

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transmittance (TOT) method (NIOSH protocol). Water-soluble ions (Na+, NH4+, K+, Cl-,

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NO3- and SO42-) were measured by ion chromatography (DX90, Dionex, US). Elements 9 ACS Paragon Plus Environment

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including Al, Si, S, Cl, K, Ca, Ti, Mn, Fe, Cu, Zn, Br, and Pb were measured by X-ray

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fluorescence spectrometry (XRF, Epsilon5, PANalytical, the Netherlands). More details

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of the chemical components analyses and their concentrations refer to Table S2 and our

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previous publication.41

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2.4 Auxiliary Data. The meteorological data (e.g., temperature, precipitation, visibility

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and wind speed) during the sampling period were obtained from Weather Underground

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(http://www.wunderground.com/). Correlation analysis was performed with SPSS

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software (IBM SPSS Statistics 20). The hourly ozone (O3) concentration data were

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obtained from Guangdong Environmental Monitoring Center and 24 h integration of O3

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was obtained for further analysis.

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3. RESULTS AND DISCUSSION

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3.1 Concentrations of Proteinaceous Matter. Proteins (MW > 5 kDa) and 15 AAs,

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i.e., Asp, Glu, Asn, Ser, Gln, His, Gly, Thr, Arg, Ala, Tyr, Val, Met, Phe and Lys, were

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detected in our samples. As shown in Table 1, the annual protein concentrations ranged

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from 0.20 to 1.86 µg m-3 with an average of 0.79 ± 0.47 µg m-3, and the concentrations of

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total FAAs were from 0.06 to 0.28 µg m-3 (average: 0.13 ± 0.05 µg m-3).

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Table 2 gives an overview of proteins and total FAAs in particulate matter with

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different size ranges (i.e., total suspended particle (TSP), coarse particulate matter (PM10)

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and PM2.5) detected in different regions. Limited studies have reported the data of

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in different regions.16-18, 20 It is worth noting that much higher protein levels (2.08–36.7

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µg m-3) determined by BCA method were observed in Hefei, China.14 The discrepancy

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could be derived from the removal of LMW interfering substances before BCA analysis.

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It has been suggested that some LMW substances may react with BCA reagents, such as

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humic acid and glucose.47, 48 Size-exclusion column is suitable for removing interferences

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such as soot, ammonium sulfate and humic like substances (HULIS), and most

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importantly, FAAs,6, 49 which were also analyzed in this study.

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The concentrations of total FAAs in our observation were comparable to those

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observed in PM2.5 in continental regions, such as urban/suburban areas of Xi’an,21

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Nanjing24 and Hong Kong,25 and rural areas of California27, 46 and North Carolina.22, 45 In

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contrast, lower concentrations have been found in most of the marine and polar regions,

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such as the Atlantic Ocean (cruise campaign),11 the North Pacific Ocean (cruise

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campaign),33 the Mediterranean (Finokalia station)34 and the Arctic (Svalbard islands).36

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The concentrations of FAAs in coastal region increased under the continental influence

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such as the results from coastal Qingdao and the Yellow Sea, indicating the significant

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contribution of continental sources.29

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Proteins and total FAAs contributed 1.9% (0.6–3.7%) and 0.3% (0.2–0.6%) to PM2.5,

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respectively (Table 1). The results are comparable to the reported contributions of

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proteinaceous matter to PM2.5 in previous studies: for proteins, the contributions of 2.0%

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in urban Munich6 and 0–1.5% in North Carolina;17 for FAAs, the contribution of 0.7–1.0%

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3.2 Compositions of Free Amino Acids. Among the investigated FAAs, Gly was the

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most abundant FAA species, contributing 19.9% to the total FAAs (Figure 1).

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Subsequently, Val, Met and Phe accounted for 18.5%, 16.1% and 13.5% of the total

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FAAs, respectively. The minor species, such as Lys, Thr, Ser, Ala, Arg and Glu,

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contributed 2.5–7.9% and the other five ones, i.e., Asn, Gln, Asp, Tyr and His, together

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accounted for only 8.1% of the total FAAs. As shown in previous studies, the

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compositions of ambient FAAs varied among different locations. In the Chinese cities of

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Nanjing and Xi’an, Gly, Cys, Val and Ala were observed as the dominant FAAs in

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urban/suburban aerosols,21, 24 while, in North Carolina, Gly, Ala, Asp and Arg were the

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major species.22,

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species in aerosols.35, 36

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In polar regions, Gly, Ser and Arg were the most abundant FAA

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In general, Gly has been found as a dominant species in many locations.21, 22, 28, 33, 34, 36

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Its high levels in aerosols could be due to the ubiquity of Gly in the environment, which

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is a fundamental component of the most abundant fibrous proteins in animals

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(collagen).50 Other Gly-rich proteins such as elastin and certain keratins (e.g., silk

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fibroins) also exist commonly in the nature, which may partially explain the high

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occurrence of Gly.22 Moreover, the high abundance of Gly may also be attributed to its

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low photochemical reactivity with a half-life longer than 2000 h in aqueous phase.51 Phe

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had an intermediate reactivity with a half-life of 21 h.51 Met is a common constituent of

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proteins in all organisms, but can be oxidized to methionine sulfoxide easily by O3 with a

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half-life less than 2.5 h.36,

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Thus, the high distribution of Met in Tianhu and its 12

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instability indicate a possible local source of this AA.

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3.3 Seasonal Trends of Proteinaceous Matter. Figure 2 shows the temporal variations

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of PM2.5, proteins, total FAAs and other chemical species including OC, EC, and

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water-soluble ions at Tianhu. Ozone and metrological data were also displayed in the

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same figure. The concentrations of proteins and total FAAs peaked in October, and

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reached minimums in July and December, respectively.

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Proteins and total FAAs showed similar temporal trends with O3, PM2.5 and its major

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chemical components (e.g., OC, EC, SO42-, NH4+ and K+). The highest protein level on

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average was found in autumn (Sep.–Nov.), followed by winter (Dec.–Feb.), summer

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(Jun.–Aug.) and spring (Mar.–May). As shown in Figure 2a and 2e, the concentrations of

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proteinaceous matter were highly sensitive to rainfall events. The averaged protein

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content in the rainy period (Apr.–mid-Sep., 0.52 ± 0.30 µg m-3) was only half of that in

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the dry period (1.02 ± 0.47 µg m-3), similar to the results reported in Mexico City12 and

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Hefei.14 The discrepancy is ascribed to the wet deposition in rainy period and the

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aerosolization of dry soils during dry period.14 The contributions of proteins to PM2.5

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were observed slightly lower in spring (1.7%) and summer (1.8%) than those in autumn

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(1.9%) and winter (2.3%). It suggests the importance of wet deposition on the occurrence

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of aerosol proteinaceous matter in the PRDR (Figure 2).

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Total FAAs showed similar seasonal variation to that of proteins with the highest

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seasonal average in autumn, followed by winter, summer and spring. The concentrations

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of total FAAs in the rainy period (0.10 ± 0.03 µg m-3) were also lower than that in the dry 13 ACS Paragon Plus Environment

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period (0.14 ± 0.05 µg m-3), again showing the influence of wet deposition. Enhancement

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of total FAAs in autumn was also observed in the previous observations in two Chinese

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cities, Hong Kong25 and Xi’an.21 Gly, Val, Met, Phe, Lys, Arg, Ala and Thr were found

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with higher concentrations in autumn than those in the other seasons (Table 1), but the

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minorities (i.e., Glu, Asn, Gln, His and Tyr) had relatively constant concentrations

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throughout the year. Constant contributions of total FAAs to PM2.5 were also observed

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during the sampling period (~0.3%).

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The enhancements of proteins and most FAAs in autumn could be due to the

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biomass/biofuel burning in this region (e.g., straw burning in harvest season and other

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burning activities).52 This is inferred by the highest seasonal K+ concentration and OC/EC

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ratio observed in autumn at this site.41 However, the contributions of other sources to

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proteinaceous matter could not be ruled out considering the co-enhancements of NH4+,

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SO42- and soil-related elements. The high levels of O3 in autumn (Figure 2b) may also

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lead to enhanced photochemical release of FAAs via the degradation of proteins (see

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more discussion in Section 3.5).51, 53

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3.4 Source Analysis. Aerosol proteinaceous matter could be primarily derived from

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biogenic activities, biomass burning, and agricultural activities.10, 14, 54 Free amino acids

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in aerosols might be secondarily produced by direct photolysis (UV radiation),

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photochemical hydrolysis (oxidative attack of ·OH or O3) and enzyme-based hydrolysis

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of HMW proteinaceous matter.37,

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between proteins and total FAAs (r = 0.74, p < 0.01). Dominant FAA species e.g., Gly,

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In this study, significant correlation was found

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Val and Ala, also showed strong correlations with proteins (r = 0.70–0.81, p < 0.01). It

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suggests that proteins and FAAs might have common sources/related processes. In order

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to understand their source contributions, correlation analysis and positive matrix

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factorization (PMF) analysis between proteinaceous matter and other major chemical

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components in PM2.5 (i.e., OC, EC, water-soluble ions and elements) were investigated

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(Table S3 and Figure S3).

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Both proteins and total FAAs showed significant correlations with NH4+ (r = 0.74 and

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0.80, respectively, p < 0.01), which was also observed in previous studies,55, 56 suggesting

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similar sources and sinks of these nitrogen species. NH4+ in the atmosphere, the

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protonation product of NH3, is tightly related to the processes of livestock excreta and

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fertilizer application,57,

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organic nitrogen.59 Therefore, these activities could be the sources of aerosol

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proteinaceous matter in this study, which is the dominant contributor to proteinaceous

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matter, contributed 48.8% for proteins and 41.4% for total FAAs, respectively (Details of

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PMF analysis see SI). The production from photochemical decomposition of dissolved

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humic materials can be another possible source, which has already been reported as a

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source of FAAs and NH4+.60 Additionally, urea cycle of organisms could be the other

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source of proteinaceous matter, suggested by the significant correlation between NH4+

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and Arg (r = 0.71, p < 0.01), an AA tightly connected with urea cycle.61

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which have been suggested as the sources of atmospheric

In our observation, proteins and total FAAs were well correlated with non-sea salt

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potassium (r = 0.79 and 0.69, respectively, p < 0.01, nss-K+ = K+ - 0.037 × Na+), a

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commonly used tracer of biomass burning.52, 62 It suggests that biomass burning, which

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has been reported previously to release bio-molecules, such as cholesterol, proteins and

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AAs,14, 36, 63 was an important source of aerosol proteinaceous matter at this site. The

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contributions of biomass burning to the measured proteins and total FAAs were 21.0%

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and 28.9%, respectively (Details of PMF analysis see SI).

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The correlations between proteinaceous matter and crustal materials (CM) have also

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been found, pointing to the influence of soil related activities. CM was calculated as

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below:41 CM = 2.20Al + 2.49Si + 1.63Ca + 2.42Fe + 1.94[Ti] (1)

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Fair correlation was observed between total FAAs and CM (r = 0.52, p < 0.01), while

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significant correlation between proteins and CM (r = 0.73, p < 0.01) was found. Soil and

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fugitive dust were found to contain proteinaceous matter, such as pollens and pollen

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fragments, animal dander and molds,4 which can be the source of aerosol proteinaceous

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matter. Soil from the nearby wooden and agricultural fields may release organic nitrogen

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in the form of proteinaceous matter into the atmosphere. The contributions of fugitive

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dust/soil to proteins differed significantly from it to total FAAs (proteins: 26.7%, total

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FAAs: 7.0%) (Details of PMF analysis see SI), which may be due to the polymeric state

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of organic nitrogen in soil (e.g, peptides, proteins and protein-humic complex).48, 64

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3.5 Atmospheric Degradation of Proteinaceous Matter. As shown in Figure 3a and

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3b, we found that both proteins and total FAAs showed significant correlations with O3 (r 16 ACS Paragon Plus Environment

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= 0.63 and 0.70, respectively, p < 0.01). It suggests that proteinaceous matter may be

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involved in O3 related processes. Previous studies have shown that O3 may promote the

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release of proteinaceous matter from suspending plant material (e.g., pollen), leading to

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the increasing levels of biological aerosols.65, 66 Additionally, O3 can also induce chemical

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modifications of proteinaceous matter via protein oxidation, nitration and oligomerization,

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which may promote the allergic potential of proteinaceous matter.67-71 Moreover, HMW

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proteinaceous matter under the influence of O3 could also be degraded into LMW

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proteinaceous matter (i.e., LMW proteins, peptides and FAAs) to have possible impacts

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on nitrogen cycle.37, 51, 53

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In our study, more significant correlations were observed for [FAAs] and [Gly] with

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[O3][Proteins] (r = 0.83 and 0.90, respectively, p < 0.01) than with [O3] (r = 0.70 and 0.74,

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respectively, p < 0.01) (Figure 3c and 3d), indicating that O3 related degradation of

307

proteins may happen and lead to the formation of FAAs. Free amino acids, especially Gly,

308

have been reported to be preferentially released from the model proteins upon the

309

oxidation by ·OH in aqueous phase.38 A similar process between proteins and FAAs may

310

occur under the influence of O3 in the atmosphere. Moreover, a series of previous

311

experimental studies have demonstrated that the reactions between proteins and

312

atmospheric oxidants including O3, NO2, and ·OH are second-order.38, 67, 68, 70, 72, 73 Thus,

313

the production of FAAs and Gly would be characterized as a second-order reaction

314

dependent on the concentrations of precursor proteins/peptides and O3. The possible

315

reaction mechanism can be expressed as follow: 17 ACS Paragon Plus Environment

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Page 18 of 33

Proteins/Peptides(HMW) + O3 → Proteins/Peptides (LMW) + FAAs (αGly + …) (2) d[AAs] = αkProtein [O3 ] (3) dt 316

where k is second-order rate coefficient and α is stoichiometric coefficient. Thus, the

317

slope of the fitted lines in Figure 3c and 3d would correspond to αk∆t. Previous studies of

318

kinetic experiments have reported that k is in the order of 10-15–10-14 cm3 s-1.67,

319

Assuming the typical atmospheric reaction time (∆t) of 2–3 h, α can be estimated to be

320

3×10-4–3×10-3 for FAAs and 10-4–10-3 for Gly, respectively. These α values are slightly

321

lower than the previously estimated α for the degradation of tripeptides (10-3–7×10-2)

322

by ·OH in aqueous phase.38 This seems reasonable as proteins are larger molecules

323

compared to tripeptides and O3 is a weaker oxidant than ·OH, so that lower α values are

324

expected.

68

325

This proposed mechanism provides a new insight into the transformation of aerosol

326

proteinaceous matter in the atmosphere. Although the kinetics of protein/peptide

327

degradation upon O3 cannot be explicitly demonstrated in our observation, the importance

328

of atmospheric oxidant on the existence of proteinaceous matter in the atmosphere should

329

be highlighted. Reactions of proteinaceous matter with some air pollutants (e.g., O3 and

330

NOx) have received considerable amount of attention, which can alter the physical,

331

chemical and biological properties of proteinaceous matter.67-69, 74 Besides, ·OH can be

332

quickly produced with the photolysis of O3 by solar UV radiation in the atmosphere.75

333

Thus, the degradation mechanisms of proteinaceous matter with O3 may contain a

334

number of reaction pathways and should be further studied in field measurements and 18 ACS Paragon Plus Environment

Page 19 of 33

335

Environmental Science & Technology

laboratory simulations.

336

Furthermore, the release of FAAs via the atmospheric processes of HMW

337

proteinaceous matter may have an implication on the bioavailability of atmospheric

338

organic nitrogen. It is believed that proteins are not directly avaliable to plants except in

339

some special conditions, such as the symbiosis with fungi, the exudation of proteolytic

340

enzymes from roots and the endocytosis of root cells.76, 77 However, airborne FAAs are

341

particularly bioavailable upon deposition and play important roles on ecological

342

processes and plant nutrition.36,

343

generated from the degradation of HMW proteins by O3 in ambient environment. This

344

may improve the bioavailability of HMW proteinaceous matter and promote nitrogen

345

utilization in ecosystem. Although some studies have focused on the nitration and

346

oligomerization modification of proteins by air pollutants,6-9, 68 little is known about the

347

degradation of proteins/peptides in the atmosphere. Further kinetic studies of

348

protein/peptide degradation by atmospheric oxidants (e.g., O3 and ·OH) in the ambient

349

environment should be conducted to reveal the atmospheric degradation processes of

350

proteinaceous matter.

37, 46

Our observation suggests that FAAs could be

351 352

ASSOCIATED CONTENT

353

Supporting Information

354

The supporting information includes: details of PMF analysis information, quality

355

assurance of AA analysis, seasonal mass concentration of PM2.5 and the associated 19 ACS Paragon Plus Environment

Environmental Science & Technology

356

chemical components, molar and mass concentrations of proteins and FAAs, correlation

357

coefficients of proteinaceous matter and major ions as well as CM, location of the

358

sampling site, a typical chromatogram of AA standard solution and the PMF results.

359 360

AUTHOR INFORMATION

361

*Corresponding Author

362

phone: +86-135-7097-4216; e-mail: [email protected]

363

phone: +86-156-9242-3889; e-mail: [email protected]

364 365

Notes

366

The authors declare no competing financial interest.

367 368

ACKNOWLEDGMENTS

369

This work is supported by the National Natural Scientific Foundation of China (Grant No.

370

41105084 and 41675119) and the joint project of Guangdong-National Natural Science

371

Foundation of China (Grant No. U1033301). We thank Prof. Jianzhen Yu from Hong

372

Kong University of Science and Technology for the measurement of elements. S.L. and

373

F.L. thank the support of the Chinese Scholarship Council (CSC).

374 375

REFERENCES

376 377

(1) Pöschl, U., Atmospheric Aerosols: Composition, Transformation, Climate and Health Effects. Angew. Chem. Int. Ed. 2005, 44 (46), 7520-7540; DOI: 10.1002/anie.200501122.

20 ACS Paragon Plus Environment

Page 20 of 33

Page 21 of 33

378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418

Environmental Science & Technology

(2) Mikhailov, E. F.; Vlasenko, S. S.; Niessner, R.; Pöschl, U., Interaction of aerosol particles composed of protein and salts with water vapor: hygroscopic growth and microstructural rearrangement. Atmos. Chem. Phys. 2004, 4 (1), 323-350; DOI: 1680-7324/acp-4-323-2004. (3) Ariya, P. A.; Sun, J.; Eltouny, N. A.; Hudson, E. D.; Hayes, C. T.; Kos, G., Physical and chemical characterization of bioaerosols - Implications for nucleation processes. Int. Rev. Phys. Chem. 2009, 28 (1), 1-32; DOI: 10.1080/01442350802597438. (4) Miguel, A. G.; Cass, G. R.; Glovsky, M. M.; Weiss, J., Allergens in paved road dust and airborne particles. Environ. Sci. Technol. 1999, 33 (23), 4159-4168; DOI: 10.1021/es9904890. (5) Douwes, J.; Thorne, P. S.; Pearce, N.; Heederik, D., Bioaerosol Health Effects and Exposure Assessment:

Progress

and

Prospects.

Ann.

Occup.

Hyg.

2003,

47

(3),

187-200;

DOI:

10.1093/annhyg/meg032. (6) Franze, T.; Weller, M. G.; Niessner, R.; Pöschl, U., Protein nitration by polluted air. Environ. Sci. Technol. 2005, 39 (6), 1673-1678; DOI: 10.1021/es0488737. (7) Gruijthuijsen, Y. K.; Grieshuber, I.; Stocklinger, A.; Tischler, U.; Fehrenbach, T.; Weller, M. G.; Vogel, L.; Vieths, S.; Pöschl, U.; Duschl, A., Nitration enhances the allergenic potential of proteins. Int. Arch. Allergy. Immun. 2006, 141 (3), 265-275; DOI: 10.1159/000095296. (8) Yang, H.; Zhang, Y.; Pöschl, U., Quantification of nitrotyrosine in nitrated proteins. Anal. Bioanal. Chem. 2010, 397 (2), 879-886; DOI: 10.1007/s00216-010-3557-3. (9) Zhang, Y. Y.; Yang, H.; Pöschl, U., Analysis of nitrated proteins and tryptic peptides by HPLC-chip-MS/MS: site-specific quantification, nitration degree, and reactivity of tyrosine residues. Anal. Bioanal. Chem. 2011, 399 (1), 459-471; DOI: 10.1007/s00216-010-4280-9. (10) Matos, J. T. V.; Duarte, R. M. B. O.; Duarte, A. C., Challenges in the identification and characterization of free amino acids and proteinaceous compounds in atmospheric aerosols: A critical review. TrAC, Trends Anal. Chem. 2016, 75, 97-107; DOI: 10.1016/j.trac.2015.08.004. (11) Wedyan, M. A.; Preston, M. R., The coupling of surface seawater organic nitrogen and the marine aerosol as inferred from enantiomer-specific amino acid analysis. Atmos. Environ. 2008, 42 (37), 8698-8705; DOI: 10.1016/j.atmosenv.2008.04.038. (12) Rosas, I.; Yela, A.; Salinas, E.; Arreguin, R.; Rodriguez-Romero, A., Preliminary assessment of protein associated with airborne particles in Mexico City. Aerobiologia 1995, 11 (2), 81-86; DOI: 10.1007/bf02738271. (13) Gutiérrez-Castillo, M. E.; Olivos-Ortiz, M.; De Vizcaya-Ruiz, A.; Cebrián, M. E., Chemical characterization of extractable water soluble matter associated with PM10 from Mexico City during 2000. Chemosphere 2005, 61 (5), 701-710; DOI: 10.1016/j.chemosphere.2005.03.063. (14) Kang, H.; Xie, Z.; Hu, Q., Ambient protein concentration in PM10 in Hefei, central China. Atmos. Environ. 2012, 54, 73-79; DOI: 10.1016/j.atmosenv.2012.03.003. (15) Staton, S. J. R.; Woodward, A.; Castillo, J. A.; Swing, K.; Hayes, M. A., Ground level environmental protein concentrations in various ecuadorian environments: Potential uses of aerosolized protein for ecological research. Ecol. Indic. 2015, 48, 389-395; DOI: 10.1016/j.ecolind.2014.08.036. (16) Chen, Q.; Hildemann, L. M., Size-Resolved Concentrations of Particulate Matter and Bioaerosols Inside

versus

Outside

of

Homes.

Aerosol

Sci.

Technol.

2009,

10.1080/02786820902882726.

21 ACS Paragon Plus Environment

43

(7),

699-713;

DOI:

Environmental Science & Technology

419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459

Page 22 of 33

(17) Menetrez, M. Y.; Foarde, K. K.; Dean, T. R.; Betancourt, D. A.; Moore, S. A., An evaluation of the protein

mass

of

particulate

matter.

Atmos.

Environ.

2007,

41

(37),

8264-8274;

DOI:

10.1016/j.atmosenv.2007.06.021. (18) Menetrez, M. Y.; Foarde, K. K.; Esch, R. K.; Schwartz, T.; Dean, T. R.; Hays, M. D.; Cho, S. H.; Betancourt, D. A.; Moore, S., An evaluation of indoor and outdoor biological particulate matter. Atmos. Environ. 2009, 43 (34), 5476-5483; DOI: 10.1016/j.atmosenv.2009.07.027. (19) Rathnayake, C. M.; Metwali, N.; Baker, Z.; Jayarathne, T.; Kostle, P. A.; Thorne, P. S.; Oshaughnessy, P. T.; Stone, E. A., Urban Enhancement of PM10 Bioaerosol Tracers Relative to Background Locations in the Midwestern United States. J. Geophys. Res. 2016, 121 (9), 5071-5089; DOI: 10.1002/2015jd024538. (20) Boreson, J.; Dillner, A. M.; Peccia, J., Correlating bioaerosol load with PM2.5 and PM10cf concentrations: a comparison between natural desert and urban-fringe aerosols. Atmos. Environ. 2004, 38 (35), 6029-6041; DOI: 10.1016/j.atmosenv.2004.06.040. (21) Ho, K. F.; Ho, S. S. H.; Huang, R.; Liu, S. X.; Cao, J.; Zhang, T.; Chuang, H. C.; Chan, C. S.; Hu, D.; Tian, L., Characteristics of water-soluble organic nitrogen in fine particulate matter in the continental area of China. Atmos. Environ. 2015, 106, 252-261; DOI: 10.1016/j.atmosenv.2015.02.010. (22) Samy, S.; Robinson, J.; Rumsey, I. C.; Walker, J. T.; Hays, M. D., Speciation and trends of organic nitrogen in southeastern US fine particulate matter (PM2.5). J. Geophys. Res. 2013, 118 (4), 1996-2006; DOI: 10.1029/2012jd017868. (23) Di Filippo, P.; Pomata, D.; Riccardi, C.; Buiarelli, F.; Gallo, V.; Quaranta, A., Free and combined amino acids in size-segregated atmospheric aerosol samples. Atmos. Environ. 2014, 98, 179-189; DOI: 10.1016/j.atmosenv.2014.08.069. (24) Yang, H.; Yu, J. Z.; Ho, S. S. H.; Xu, J.; Wu, W.-S.; Wan, C. H.; Wang, X.; Wang, X.; Wang, L., The chemical composition of inorganic and carbonaceous materials in PM2.5 in Nanjing, China. Atmos. Environ. 2005, 39 (20), 3735-3749; DOI: 10.1016/j.atmosenv.2005.03.010. (25) Yu, J. Z.; Schauer, J., Chemical characterization of water soluble organic compounds in particulate matters in Hong Kong. In Report from Hong Kong Environmental Protection Department, 2002. (26) Mace, K. A.; Artaxo, P.; Duce, R. A., Water-soluble organic nitrogen in Amazon Basin aerosols during the dry (biomass burning) and wet seasons. J. Geophys. Res. 2003, 108 (D16), 1-14; DOI: 10.1029/2003jd003557. (27) Zhang, Q.; Anastasio, C.; Jimemez-Cruz, M., Water-soluble organic nitrogen in atmospheric fine particles (PM2.5) from Northern California. J. Geophys. Res. 2002, 107 (D11), 1-9; DOI: 10.1029/2001jd000870. (28) Barbaro, E.; Zangrando, R.; Moret, I.; Barbante, C.; Cescon, P.; Gambaro, A., Free amino acids in atmospheric particulate matter of Venice, Italy. Atmos. Environ. 2011, 45, 5050-5057; DOI: 10.1016/j.atmosenv.2011.01.068. (29) Shi, J.; Gao, H.; Qi, J.; Zhang, J.; Yao, X., Sources, compositions, and distributions of water‐soluble organic nitrogen in aerosols over the China Sea. J. Geophys. Res. 2010, 115, 1-13; DOI: 10.1029/2009jd013238. (30) Yang, H.; Xu, J.; Wu, W.; Wan, C. H.; Yu, J. Z., Chemical Characterization of Water-Soluble Organic Aerosols at Jeju Island Collected During ACE-Asia. Environ. Chem. 2004, 1 (1), 13-17; DOI: 10.1071/en04006.

22 ACS Paragon Plus Environment

Page 23 of 33

460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500

Environmental Science & Technology

(31) Mace, K. A.; Duce, R. A.; Tindale, N. W., Organic nitrogen in rain and aerosol at Cape Grim, Tasmania, Australia. J. Geophys. Res. 2003, 108 (D11), 1-14; DOI: 10.1029/2002jd003051. (32) Mace, K. A.; Kubilay, N.; Duce, R. A., Organic nitrogen in rain and aerosol in the eastern Mediterranean atmosphere: An association with atmospheric dust. J. Geophys. Res. 2003, 108 (D10), 1-11; DOI: 10.1029/2002JD002997. (33) Matsumoto, K.; Uematsu, M., Free amino acids in marine aerosols over the western North Pacific Ocean. Atmos. Environ. 2005, 39 (11), 2163-2170; DOI: 10.1016/j.atmosenv.2004.12.022. (34) Mandalakis, M.; Apostolaki, M.; Tziaras, T.; Polymenakou, P.; Stephanou, E. G., Free and combined amino acids in marine background atmospheric aerosols over the Eastern Mediterranean. Atmos. Environ. 2011, 45 (4), 1003-1009; DOI: 10.1016/j.atmosenv.2010.10.046. (35) Barbaro, E.; Zangrando, R.; Vecchiato, M.; Piazza, R.; Cairns, W. R. L.; Capodaglio, G.; Barbante, C.; Gambaro, A., Free amino acids in Antarctic aerosol: potential markers for the evolution and fate of marine aerosol. Atmos. Chem. Phys. 2015, 15 (10), 5457-5469; DOI: 10.5194/acp-15-5457-2015. (36) Scalabrin, E.; Zangrando, R.; Barbaro, E.; Kehrwald, N. M.; Gabrieli, J.; Barbante, C.; Gambaro, A., Amino acids in Arctic aerosols. Atmos. Chem. Phys. 2012, 12 (21), 10453-10463; DOI: 10.5194/acp-12-10453-2012. (37) Mopper, K.; Zika, R. G., Free amino acids in marine rains: evidence for oxidation and potential role in nitrogen cycling. Nature 1987, 325 (6101), 246-249; DOI: 10.1038/325246a0. (38) Liu, F.; Lai, S.; Tong, H.; Lakey, P. S. J.; Shiraiwa, M.; Weller, M. G.; Pöschl, U.; Kampf, C. J., Release of free amino acids upon oxidation of peptides and proteins by hydroxyl radicals. Anal. Bioanal. Chem. 2017, 409 (9), 2411-2420; DOI: 10.1007/s00216-017-0188-y. (39) Ling, Z. H.; Zhao, J.; Fan, S. J.; Wang, X. M., Sources of formaldehyde and their contributions to photochemical O3 formation at an urban site in the Pearl River Delta, southern China. Chemosphere 2017, 168, 1293-1301; DOI: j.chemosphere.2016.11.140. (40) Dou, H.; Zhao, X., Climate change and its human dimensions based on GIS and meteorological statistics in Pearl River Delta, Southern China. Meteorol. Appl. 2011, 18 (1), 111-122; DOI: 10.1002/met.219. (41) Lai, S.; Zhao, Y.; Ding, A.; Zhang, Y.; Song, T.; Zheng, J.; Ho, K. F.; Lee, S.-c.; Zhong, L., Characterization of PM2.5 and the major chemical components during a 1-year campaign in rural Guangzhou, Southern China. Atmos. Res. 2016, 167, 208-215; DOI: 10.1016/j.atmosres.2015.08.007. (42) Chen, X.; Lai, S.; Gao, Y.; Zhang, Y.; Zhao, Y.; Chen, D.; Zheng, J.; Zhong, L.; Lee, S.; Chen, B., Reconstructed Light Extinction Coefficients of Fine Particulate Matter in Rural Guangzhou, Southern China. Aerosol Air Qual. Res. 2016, 16 (8), 1981-1990; DOI: 10.4209/aaqr.2016.02.0064. (43) Chen, Q.; Hildemann, L. M., The effects of human activities on exposure to particulate matter and bioaerosols in residential homes. Environ. Sci. Technol. 2009, 43 (13), 4641-4646; DOI: 10.1021/es802296j. (44) Henderson, J.; Ricker, R. D.; Bidlingmeyer, B. A.; Woodward, C., Rapid, accurate, sensitive, and reproducible HPLC analysis of amino acids. Amino acid analysis using Zorbax Eclipse-AAA columns and the Agilent 1100 HPLC. In Agilent Technologies, 2000; Vol. 1100, pp 1-10. (45) Samy, S.; Robinson, J.; Hays, M. D., An advanced LC-MS (Q-TOF) technique for the detection of amino acids

in

atmospheric

aerosols.

Anal.

Bioanal.

Chem.

2011,

10.1007/s00216-011-5238-2.

23 ACS Paragon Plus Environment

401

(10),

3103-3113;

DOI:

Environmental Science & Technology

501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541

Page 24 of 33

(46) Zhang, Q.; Anastasio, C., Free and combined amino compounds in atmospheric fine particles (PM2.5) and fog waters from Northern California. Atmos. Environ. 2003, 37 (16), 2247-2258; DOI: 10.1016/s1352-2310(03)00127-4. (47) Brown, R. E.; Jarvis, K. L.; Hyland, K. J., Protein measurement using bicinchoninic acid: elimination of interfering substances. Anal. Biochem. 1989, 180 (1), 136-139; DOI: 10.1016/0003-2697(89)90101-2. (48) Roberts, P.; Jones, D. L., Critical evaluation of methods for determining total protein in soil solution. Soil Biol. Biochem. 2008, 40 (6), 1485-1495; DOI: 10.1016/j.soilbio.2008.01.001. (49) Liu, F.; Lai, S.; Reinmuthselzle, K.; Scheel, J. F.; Frohlichnowoisky, J.; Despres, V. R.; Hoffmann, T.; Pöschl, U.; Kampf, C. J., Metaproteomic analysis of atmospheric aerosol samples. Anal. Bioanal. Chem. 2016, 408 (23), 1-12; DOI: 10.1007/s00216-016-9747-x. (50) Voet, D.; Voet, J. G.; Pratt, C. W., Fundamentals of Biochemistry. John Wiley & Sons: 2008. (51) McGregor, K. G.; Anastasio, C., Chemistry of fog waters in California's Central Valley: 2. Photochemical transformations of amino acids and alkyl amines. Atmos. Environ. 2001, 35 (6), 1091-1104; DOI: 10.1016/S1352-2310(00)00282-X. (52) Ho, K. F.; Engling, G.; Ho, S. S. H.; Huang, R.; Lai, S.; Cao, J.; Lee, S. C., Seasonal variations of anhydrosugars in PM2.5 in the Pearl River Delta Region, China. Tellus. B 2014, 66, 1-14; DOI: 10.3402/tellusb.v66.22577. (53) Milne, P.; Zika, R., Amino acid nitrogen in atmospheric aerosols: Occurrence, sources and photochemical modification. J. Atmos. Chem. 1993, 16 (4), 361-398; DOI: 10.1007/bf01032631. (54) Scheller, E., Amino acids in dew – origin and seasonal variation. Atmos. Environ. 2001, 35 (12), 2179-2192; DOI: 10.1016/S1352-2310(00)00477-5. (55) Gorzelska, K.; Galloway, J., Amine nitrogen in the atmospheric environment over the North Atlantic Ocean. Global Biogeochem. Cy. 1990, 4 (3), 309-333; DOI: 10.1029/gb004i003p00309. (56) Kieber, R. J.; Long, M. S.; Willey, J. D., Factors influencing nitrogen speciation in coastal rainwater. J. Atmos. Chem. 2005, 52 (1), 81-99; DOI: 10.1007/s10874-005-8354-6. (57) Zhang, Y.; Dore, A. J.; Ma, L.; Liu, X. J.; Ma, W. Q.; Cape, J. N.; Zhang, F. S., Agricultural ammonia emissions inventory and spatial distribution in the North China Plain. Environ. Pollut. 2010, 158 (2), 490-501; DOI: 10.1016/j.envpol.2009.08.033. (58) Zhang, Y.; Luan, S.; Chen, L.; Shao, M., Estimating the volatilization of ammonia from synthetic nitrogenous fertilizers used in China. J. Environ. Manage. 2011, 92 (3),

480-493; DOI:

10.1016/j.jenvman.2010.09.018. (59) Ham, Y. S.; Tamiya, S., Contribution of dissolved organic nitrogen deposition to total dissolved nitrogen deposition under intensive agricultural activities. Water Air Soil Poll. 2006, 178 (1), 5-13; DOI: 10.1007/s11270-006-9109-y. (60) Tarr, M. A.; Wang, W.; Bianchi, T. S.; Engelhaupt, E., Mechanisms of ammonia and amino acid photoproduction from aquatic humic and colloidal matter. Water Res. 2001, 35 (15), 3688-3696; DOI: 10.1016/S0043-1354(01)00101-4. (61) Micallef, B. J.; Shelp, B. J., Arginine Metabolism in Developing Soybean Cotyledons : II. Biosynthesis. Plant Physiol. 1989, 90 (2), 631-634; DOI: 10.1104/pp.90.2.631. (62) Kunwar, B.; Kawamura, K., One-year observations of carbonaceous and nitrogenous components and major ions in the aerosols from subtropical Okinawa Island, an outflow region of Asian dusts. Atmos. Chem.

24 ACS Paragon Plus Environment

Page 25 of 33

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Phys. 2014, 14 (1), 1819-1836; DOI: 10.5194/acp-14-1819-2014. (63) Rogge, W. F.; Hildemann, L. M.; Mazurek, M. A.; Cass, G. R.; Simoneit, B. R. T., Sources of fine organic aerosol. 1. Charbroilers and meat cooking operations. Environ. Sci. Technol. 1991, 25 (6), 1112-1125; DOI: 10.1021/es00018a015. (64) Warren, C., Organic N molecules in the soil solution: what is known, what is unknown and the path forwards. Plant Soil 2014, 375 (1-2), 1-19; DOI: 10.1007/s11104-013-1939-y. (65) Mumford, R. A.; Lipke, H.; Laufer, D. A.; Feder, W. A., Ozone-induced changes in corn pollen. Environ. Sci. Technol. 1972, 6 (5), 427-430; DOI: 10.1021/es60064a010. (66) Beck, I.; Jochner, S.; Gilles, S.; Mcintyre, M.; Buters, J. T. M.; Schmidtweber, C. B.; Behrendt, H.; Ring, J.; Menzel, A.; Traidlhoffmann, C., High Environmental Ozone Levels Lead to Enhanced Allergenicity of Birch Pollen. PLOS ONE 2013, 8 (11), 1-7; DOI: 10.1371/journal.pone.0080147. (67) Shiraiwa, M.; Selzle, K.; Yang, H.; Sosedova, Y.; Ammann, M.; Pöschl, U., Multiphase Chemical Kinetics of the Nitration of Aerosolized Protein by Ozone and Nitrogen Dioxide. Environ. Sci. Technol. 2012, 46 (12), 6672-6680; DOI: 10.1021/es300871b. (68) Kampf, C. J.; Liu, F.; Reinmuthselzle, K.; Berkemeier, T.; Meusel, H.; Shiraiwa, M.; Pöschl, U., Protein Cross-Linking and Oligomerization through Dityrosine Formation upon Exposure to Ozone. Environ. Sci. Technol. 2015, 49 (18), 10859-10866; DOI: 10.1021/acs.est.5b02902. (69) Sharma, V. K.; Graham, N. J. D., Oxidation of Amino Acids, Peptides and Proteins by Ozone: A Review. Ozone-Sci. Eng. 2010, 32 (2), 81-90; DOI: 10.1080/01919510903510507. (70) Liu, F.; Lakey, P.; Berkemeier, T.; Tong, H.; Kunert, A. T.; Meusel, H.; Su, H.; Cheng, Y.; Frohlich-Nowoisky, J.; Lai, S.; Weller, M. G.; Shiraiwa, M.; Poschl, U.; Kampf, C. J., Atmospheric protein chemistry influenced by anthropogenic air pollutants: nitration and oligomerization upon exposure to ozone and nitrogen dioxide. Faraday Discuss. 2017, 1-9; DOI: 10.1039/c7fd00005g. (71) Reinmuth-Selzle, K.; Kampf, C. J.; Lucas, K.; Lang-Yona, N.; Fröhlich-Nowoisky, J.; Shiraiwa, M.; Lakey, P. S. J.; Lai, S.; Liu, F.; Kunert, A. T.; Ziegler, K.; Shen, F.; Sgarbanti, R.; Weber, B.; Bellinghausen, I.; Saloga, J.; Weller, M. G.; Duschl, A.; Schuppan, D.; Pöschl, U., Air Pollution and Climate Change Effects on Allergies in the Anthropocene: Abundance, Interaction, and Modification of Allergens and Adjuvants. Environ. Sci. Technol. 2017, 51 (8), 4119-4141; DOI: 10.1021/acs.est.6b04908. (72) Shiraiwa, M.; Ammann, M.; Koop, T.; Poschl, U., Gas uptake and chemical aging of semisolid organic aerosol particles. PNAS 2011, 108 (27), 11003-11008; DOI: 10.1073/pnas.1103045108. (73) Reinmuth-Selzle, K.; Ackaert, C.; Kampf, C. J.; Samonig, M.; Shiraiwa, M.; Kofler, S.; Yang, H.; Gadermaier, G.; Brandstetter, H.; Huber, C. G.; Duschl, A.; Oostingh, G. J.; Pöschl, U., Nitration of the Birch Pollen Allergen Bet v 1.0101: Efficiency and Site-Selectivity of Liquid and Gaseous Nitrating Agents. J. Proteome Res. 2014, 13 (3), 1570-1577; DOI: 10.1021/pr401078h. (74) Lloyd, J. A.; Spraggins, J. M.; Johnston, M. V.; Laskin, J., Peptide ozonolysis: Product structures and relative reactivities for oxidation of tyrosine and histidine residues. J. Am. Soc. Mass. Spectrom. 2006, 17 (9), 1289-1298; DOI: 10.1016/j.jasms.2006.05.009. (75) Guicherit, R.; Roemer, M., Tropospheric ozone trends. Chemosphere 2000, 2 (2), 167-183; DOI: 10.1016/S1465-9972(00)00008-8. (76) Kaye, J. P.; Hart, S. C., Competition for nitrogen between plants and soil microorganisms. Trends Ecol. Evol. 1997, 12 (4), 139-143; DOI: 10.1016/s0169-5347(97)01001-x.

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(77) Paungfoo-Lonhienne, C.; Lonhienne, T. G. A.; Rentsch, D.; Robinson, N.; Christie, M.; Webb, R. I.; Gamage, H. K.; Carroll, B. J.; Schenk, P. M.; Schmidt, S., Plants can use protein as a nitrogen source without assistance from other organisms. PNAS 2008, 105 (11), 4524-4529; DOI: 10.1073/pnas.0712078105.

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Figures and Tables

589

Tables:

590

Table 1. Seasonal mass concentrations of proteins and FAAs in PM2.5 at Tianhu.

591

Table 2. Mass concentrations of proteins and total FAAs in comparison to other studies

592

(range, arithmetic mean and standard deviation).

593

Figures:

594

Figure 1. Average percentage distributions of individual AAs in PM2.5. The category of

595

“other” includes Asn (2.2 %), Gln (2.2 %), Asp (1.9 %), Tyr (1.5 %), and His (0.3 %)

596

(calculated by molar concentration).

597

Figure 2. Temporal variations of proteinaceous matter in PM2.5 and other data measured

598

at Tianhu: (a) proteins and total FAAs; (b) PM2.5 and O3; (c) OC and EC; (d) major ions

599

(Na+, NH4+, K+, Cl-, NO3-, and SO42-); (e) precipitation (the precipitation data were

600

obtained from http://www.wunderground.com/, and the shadow area is the rainy period).

601

Figure 3. Correlations between proteinaceous matter in PM2.5 and ambient O3: (a)

602

proteins vs. O3; (b) total FAAs vs. O3; (c) total FAAs vs. [O3][Proteins]; (d) Gly vs.

603

[O3][Proteins].

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Table 1. Seasonal mass concentrations of proteins and FAAs in PM2.5 at Tianhu.

604 605

606

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Compounds

Annual

Spring a

Summer a

Autumn a

Winter a

Proteins (µg m-3) FAAs (×10-3 µg m-3) Aspartic acid (Asp) Glutamic acid (Glu) Asparagine (Asn) Serine (Ser) Glutamine (Gln) Histidine (His) Glycine (Gly) Threonine (Thr) Arginine (Arg) Alanine (Ala) Tyrosine (Tyr) Valine (Val) Methionine (Met) Phenylalanine (Phe) Lysine (Lys) Total FAAs Proteins/PM2.5 (%) Total FAAs/PM2.5 (%)

0.79 ± 0.47

0.55 ± 0.43

0.61 ± 0.36

1.05 ± 0.45

0.93 ± 0.48

2.47 ± 0.80 3.37 ± 0.90 2.91 ± 0.67 4.68 ± 1.49 2.87 ± 0.75 0.43 ± 0.19 26.39 ± 14.89 5.31 ± 4.12 3.44 ± 2.33 4.60 ± 2.84 2.04 ± 0.68 24.55 ± 13.68 21.44 ± 9.44 17.96 ± 6.58 10.45 ± 6.35 132.91 ± 48.38 1.94 ± 0.73 0.34 ± 0.10

2.69 ± 0.85 3.31 ± 0.40 2.94 ± 0.21 5.13 ± 2.06 2.96 ± 0.26 0.51 ± 0.12 17.85 ± 9.60 2.95 ± 1.48 2.54 ± 0.72 2.78 ± 1.04 1.75 ± 0.19 16.06 ± 5.36 20.86 ± 8.73 15.51 ± 2.33 9.36 ± 4.59 107.20 ± 25.66 1.68 ± 0.74 0.39 ± 0.08

2.38 ± 0.72 3.46 ± 1.23 2.96 ± 1.15 4.68 ± 1.28 3.06 ± 1.32 0.45 ± 0.24 21.62 ± 7.89 4.51 ± 1.68 2.50 ± 0.61 3.59 ± 1.08 1.99 ± 0.69 17.65 ± 10.73 21.30 ± 11.09 14.64 ± 4.54 10.25 ± 5.29 115.04 ± 34.76 1.77 ± 0.95 0.32 ± 0.11

3.04 ± 0.89 3.80 ± 0.71 2.95 ± 0.47 5.11 ± 1.52 2.93 ± 0.52 0.48 ± 0.24 42.06 ± 18.14 6.88 ± 2.84 6.40 ± 3.09 6.86 ± 3.53 2.52 ± 0.86 40.75 ± 13.70 26.55 ± 9.95 22.29 ± 5.95 13.06 ± 4.46 185.70 ± 55.65 1.89 ± 0.41 0.33 ± 0.07

1.92 ± 0.25 2.97 ± 0.85 2.82 ± 0.44 3.97 ± 0.94 2.59 ± 0.24 0.30 ± 0.05 23.13 ± 10.25 6.39 ± 6.57 2.42 ± 0.75 4.90 ± 3.01 1.87 ± 0.53 23.13 ± 7.65 17.59 ± 6.24 19.09 ± 8.52 9.16 ± 9.09 122.63 ± 30.57 2.33 ± 0.59 0.32 ± 0.10

a

the sampling period was classified into four seasons: spring (Mar.-May), summer (Jun.-Aug.), autumn (Sep.- Nov.), and winter (Dec.-Feb.).

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Table 2. Mass concentrations of proteins and total FAAs in comparison to other studies (range, arithmetic mean and standard deviation). Sampling site

Type of aerosol

Sampling time

PM size

Concentrations Range

Reference Mean± SD

a

-3

Proteins (µg m ) Guangzhou, China

rural

March 2012-February 2013

PM2.5

0.20-1.86

0.79±0.47

this study

North Carolina (Orange County), US

rural

March-May 2007

PM2.5

< MDL -0.14

0.09

18

California (outside of home), US

suburban

October 2005-May 2006

PM2.5

0.07-7.20

0.60

16

North Carolina (Chapel Hill), US

suburban

August 2003-January 2004

PM2.5

< MDL-0.20

0.11

17

Arizona (Phoenix), US

suburban

2002-2003 (winter, spring and summer)

PM2.5

0.40-3.30

PM2.5

0.30-1.00

PM10

< MDL-4.98

1.96

PM10

0.42-4.91

1.51

rural Iowa, US

urban

2012 (January, April, July and October)

rural

b

20

19

Hefei, China

urban

June 2008-February 2009

PM10

2.08-36.7

11.4

14

California (outside of home), US

suburban

October 2005-May 2006

PM10

0.08-8.30

0.90

16

North Carolina (Orange County), US

rural

March-May 2007

PM10

< MDL-0.43

0.27

18

Mexico City, Mexico

urban/suburban

July-December 2000

PM10

0.04-0.17

13

Ecuador, South America

rural

2009 (several months)

TSP

0.07-0.32

15

Crete island (Finokalia), Greece

marine

June-August 2007

TSP

0.05-1.21

0.42

34

California (outside of home), US

suburban

October 2005-May 2006

TSP

0.20-9.30

1.40

16

rural

March 2012-February 2013

PM2.5

59.2-279

133 ± 48.4

Total FAAs (×10-3 µg m-3) Guangzhou, China Xi’an, China

urban

July 2008-August 2009

610

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PM2.5

44.1-592

c

181

c

this study 21

Environmental Science & Technology

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Table 2. Continued. Sampling site

Type of aerosol

Sampling time

PM size

Concentrations Range

-3

Mean± SD

Reference a

-3

Total FAAs (×10 µg m ) Roma, Italy

urban

2013 (winter)

PM2.5

167

2013 (summer)

PM2.5

193

23

North Carolina (Research Triangle Park), US

suburban

September-October 2010

PM2.5

2.00-31.0

11.0

22

North Carolina (Duke University forest), US

rural

July-August 2010

PM2.5

11.0-40.0

22.0

45

Nanjing (Nanjing University), China

urban suburban rural rural

PM2.5 PM2.5 PM2.5 PM2.5 PM2.5

81.9-188 39.3-162 58.5-396

129 84.9 189 25.7 56.8

24

Nanjing (Purple Mountain), China Jeju Island (Gusan), Korea California (Davis), US

February 2001 September 2001 February 2001 March-April 2001 August 1997-July 1998

Hong Kong, China

urban

November 2000-October 2001

PM2.5

83.9-192

Roma, Italy

urban

2013 (winter)

PM10

2013 (summer)

PM10

Rondonia (Amazon Basin), Brazil MZ Station, Antarctica

rural polar

7.83-325

27, 46 25

195

23

272 d

20.6 d

1999 (wet seasons)

PM10

0.76-166

1999 (dry seasons)

PM10

0.69-42.1 d

2010-2013

PM10

1.51 c

PM10

0.10 c

Dome C Station, Antarctica

30

26

10.8 d 35

Svalbard Islands, Norway

polar

April-September 2010

PM10

0.08-0.65 c

Southern Ocean (cruise)

polar

2010-2013

TSP

0.27-1.64 c

0.48 c

35

Crete island (Finokalia), Greece

marine

June-August 2007

TSP

0.82-88.8 c

23.6 c

34

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Table 2. Continued. Sampling site

Type of aerosol

Sampling time

PM size

Concentrations Range

-3

Mean± SD

Reference a

-3

Total FAAs (×10 µg m ) Qingdao (coastal), China

617 618 619 620 621 622

marine

March-April 2006

TSP

214

South China Sea (cruise)

April-May 2005

TSP

31.0-58.2

Yellow Sea (cruise)

March 2005, April 2006

TSP

27.5-238

29

44.5 131 c

2.74 c

11

Atlantic Ocean (cruise)

marine

May-June 2003

TSP

0.41-13.7

North Pacific Ocean (cruise)

marine

May-July 2000

TSP

0.15-3.01 d

1.05 d

33

Tasmania (Cape Grim), Australia

marine

November-December 2000

TSP

1.96-21.5 d

9.79 d

31

Erdemli (Mediterranean coast), Turkey

marine

March-May 2000

TSP

3.91-110 d

36.2 d

32

a

standard deviation; below the method detection limit (< MDL); c concentrations converted from pmol m-3 to ng m-3 assuming an average molecular weight of 137 for AAs; d concentrations converted from nmol m-3 of nitrogen to ng m-3 of AAs assuming 1.4 nitrogen atoms per AA molecule and an average molecular weight of 137 for AAs. b

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623 624 625 626

Figure 1. Average percentage distributions of individual AAs in PM2.5. The category of “other” includes Asn (2.2 %), Gln (2.2 %), Asp (1.9 %), Tyr (1.5 %), and His (0.3 %) (calculated by molar concentration).

627

628 629 630 631 632

Figure 2. Temporal variations of proteinaceous matter in PM2.5 and other data measured at Tianhu: (a) proteins and total FAAs; (b) PM2.5 and O3; (c) OC and EC; (d) major ions (Na+, NH4+, K+, Cl-, NO3-, and SO42-); (e) precipitation (the precipitation data were obtained from http://www.wunderground.com/, and the shadow area is the rainy period).

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633

634 635 636 637

Figure 3. Correlations between proteinaceous matter in PM2.5 and ambient O3: (a) proteins vs. O3; (b) total FAAs vs. O3; (c) total FAAs vs. [O3][Proteins]; (d) Gly vs. [O3][Proteins].

33 ACS Paragon Plus Environment