Subscriber access provided by University of Sussex Library
Environmental Processes
Reactivity of Enveloped Virus Genome, Proteins, and Lipids with Free Chlorine and UV254 Yinyin Ye, Pin Hsuan Chang, John Hartert, and Krista R. Wigginton Environ. Sci. Technol., Just Accepted Manuscript • DOI: 10.1021/acs.est.8b00824 • Publication Date (Web): 09 Jun 2018 Downloaded from http://pubs.acs.org on June 12, 2018
Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.
is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.
Page 1 of 31
1
Environmental Science & Technology
Reactivity of Enveloped Virus Genome, Proteins, and Lipids with Free Chlorine and UV254
2 3 4
Yinyin Ye,† Pin Hsuan Chang,† John Hartert,† Krista R. Wigginton*,†
5 6
†Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, MI
7
48109-2125, United States
8 9
*Corresponding author
10
Mailing address: Department of Civil and Environmental Engineering, 1351 Beal Ave., 181
11
EWRE, Ann Arbor, MI 48109-2125, USA. Phone: +1 (734) 763-2125; Fax: +1 (734) 764-4292;
12
E-mail:
[email protected] 13 14 15 16 17 18
Word Counts
19
5490 words in Text + 1500 words in Figures + 0 words in Table + 83 words in Acknowledgements
20
= Total 7073
21 22 23
ACS Paragon Plus Environment
1
Environmental Science & Technology
Page 2 of 31
24
ABSTRACT
25
The survivability of viruses in natural and engineered systems impacts public health. Inactivation
26
mechanisms in the environment have been described for nonenveloped viruses, but it remains
27
unclear how the membrane layer of enveloped viruses influences inactivation. We applied
28
molecular tools and high-resolution mass spectrometry to measure reactions in the genome,
29
proteins, and lipids of enveloped Pseudomonas phage Phi6 during inactivation by free chlorine
30
and UV254. Free chlorine readily penetrated the lipid membrane to react with proteins in the
31
nucleocapsid and polymerase complex. The most reactive Phi6 peptides were approximately 150
32
times more reactive with free chlorine than the most reactive peptides reported in nonenveloped
33
coliphage MS2. The inactivation kinetics of Phi6 by UV254 was comparable with those of
34
nonenveloped adenovirus and coliphage MS2, and were driven by UV254 reactions with viral
35
genomes. Our research identifies molecular features of an enveloped virus that are susceptible to
36
chemical oxidants or UV radiation. Finally, the framework developed in the manuscript for
37
studying molecular reactivities of Phi6 can be adopted to investigate enveloped virus survivability
38
under various environmental conditions.
39 40
ACS Paragon Plus Environment
2
Page 3 of 31
41
Environmental Science & Technology
INTRODUCTION
42
Viruses that are transmitted through direct person-to-person contact or in large respiratory
43
droplets do not typically survive for very long outside of their host in the environment.1 On the
44
other hand, viruses that are transmitted through aerosols or by contact with water, food, and solid
45
surfaces tend to survive longer in order to come into contact with their next host.2,3 Survivability,
46
often reported as the time necessary for 90% of a population to lose infectivity (T90), can therefore
47
vary widely amongst different viruses, and depends on environmental conditions including
48
temperature,4-6 relative humidity,4-9 UV radiation,10-12 and oxidants.13-15 Survivability is also
49
impacted by virus structures. Nonenveloped viruses are generally considered more stable than
50
enveloped viruses in the environment. For example, the T90 values for nonenveloped viruses in
51
wastewater range from days to months, whereas the T90 values for enveloped viruses range from
52
several hours to days.16-18 In terms of susceptibility to chemical disinfectants, the enveloped Ebola
53
and Phi6 viruses experience higher levels of inactivation than the nonenveloped MS2 and M13
54
viruses when exposed to 0.5% NaOCl.19 Even closely related enveloped viruses can have varied
55
survivabilities. For example, the T90 of severe acute respiratory syndrome (SARS) coronavirus in
56
serum-free culture media is 9 days, whereas the T90 of human coronavirus 229E is less than 1 day
57
under the same conditions.20 The mechanistic reasons for the higher susceptibility of enveloped
58
viruses to inactivation in aqueous environments are mostly unknown.
59
Despite their greater susceptibility to environmental conditions, many enveloped viruses do
60
undergo environmental transmission. SARS coronaviruses were transmitted through airflow and
61
virus-laden fecal aerosols.21,22 Human influenza viruses retain their infectivity on the nonporous
62
surfaces, increasing their chances to infect.23,24 Avian influenza viruses are shed into water, where
63
they can survive months before being consumed by their next host.25,26 Porcine reproductive and
ACS Paragon Plus Environment
3
Environmental Science & Technology
Page 4 of 31
64
respiratory syndrome viruses can travel several kilometers via aerosols, spreading swine diseases
65
from farm to farm.27 Infectious Ebola viruses persist in patient blood, feces and urine, and can
66
survive in liquid for several days.3,28
67
Research on what makes enveloped viruses more or less persistent in the environment and
68
through disinfection processes could help with predicting risks posed by newly emerging viruses
69
that are difficult or dangerous to culture. For example, in the recent Ebola outbreak, a mechanistic
70
understanding of enveloped virus inactivation would have helped scientists predict how long Ebola
71
virus remained infective in wastewater, blood, and vomit.29 Comprehensive inactivation
72
mechanisms have been published for a limited number of nonenveloped viruses with
73
disinfectants,12,15,30,31 but are lacking for enveloped viruses. In general, UV radiation targets
74
nonenveloped virus genomes, whereas chemical oxidants inactivate nonenveloped viruses by
75
genome or protein reactions, depending on the virus and oxidant.
76
Recent fate and survival studies of enveloped viruses in the environment have adopted
77
Pseudomonas virus Phi6 as a model enveloped virus.17,32-36 Phi6 is a double stranded RNA virus.
78
The Phi6 particle is 85 nm in diameter37 and contains 11 different viral proteins.38 Like influenza
79
viruses, Phi6 is enveloped, has a segmented genome, and contains glycerophospholipids in its
80
envelope.39,40 In addition, it is the best studied virus in the family Cystoviridae, which includes the
81
only bacteriophages that have a lipid outer layer. Moreover, Phi6 is easier to work with than other
82
enveloped viruses and can be propagated to high titer levels.
83
To develop a better mechanistic understanding of enveloped virus inactivation, we employed
84
Phi6 in an initial investigation of enveloped virus reactivity with chemical oxidants and UV
85
radiation. We characterized the biomolecule reactions in Phi6 following exposure to free chlorine
86
and UV254. Phi6 inactivation, genome reactions, and protein and lipid reactions were quantified
ACS Paragon Plus Environment
4
Page 5 of 31
Environmental Science & Technology
87
with plaque assays, real-time reverse transcription polymerase chain reactions (RT-qPCR), and
88
liquid chromatography-tandem mass spectrometry (LC-MS/MS), respectively. We compared the
89
reaction rate constants of the Phi6 genome and proteins to those of nonenveloped viruses reported
90
in earlier studies and measured under similar experimental conditions to elucidate the molecular
91
features that may impact enveloped virus persistence in aqueous environments.
92 93
MATERIALS AND METHODS
94
Virus propagation and purification. Phi6 and its bacterial host Pseudomonas syringae pv.
95
phaseolicola were kindly provided by Dr. Linsey Marr’s lab at Virginia Tech. To propagate Phi6,
96
P. syringae was grown in Luria-Bertani (LB) medium containing 5 g L-1 NaCl at 26 °C and 180
97
rpm to an optical density of 0.10 at 640 nm (i.e., when the cell density was approximately 1.8 ×
98
108 cells mL-1). At that point, Phi6 was added to the bacteria at a multiplicity of infection equal to
99
2 (i.e., ratio of Phi6 plaque-forming units (PFU) to P. syringae colony forming units (CFU)), and
100
then incubated under the same conditions for 7 to 9 hours. Cells and debris were removed from
101
the virus suspension by filtering it through 0.22 μm polyethersulfone (PES, Millipore) membranes.
102
The filtered virus suspensions (~1 L) were concentrated to approximately 20 mL (i.e., ~50´
103
concentration) in a lab-scale tangential flow filtration system (Millipore) outfitted with a 30 kDa
104
cellulous filter. The concentrate was purified in a 10-40% (w/v) step sucrose gradient (average
105
65,700 × g, 1.5 h, 4 °C), then in a 40-60% (w/v) linear sucrose gradient (average 65,700 × g, 15 h,
106
4 °C). The phage band was collected with a needle and the buffer was exchanged for 5 mM
107
phosphate buffer (PBS; 10 mM NaCl, pH 7.4) with a 100 kDa Amicon Ultra-15 centrifugal filter
108
(Millipore). Virus purity was confirmed by SDS-PAGE with 8-16% TGXTM precast protein gels
109
(Bio-Rad), according to the manufacturer’s instructions (Figure S1). The final Phi6 stocks (1012
ACS Paragon Plus Environment
5
Environmental Science & Technology
Page 6 of 31
110
PFU mL-1) were filter-sterilized with 0.22 μm PES membranes, aliquoted, and stored at -80 °C
111
until use.
112
Free chlorine and UV254 experiments. Experimental virus solutions were prepared by diluting
113
Phi6 in PBS. All free chlorine and UV254 experiments were conducted at room temperature.
114
Infectious virus concentrations (PFU mL-1) were measured immediately before and after the
115
viruses were exposed to chlorine and UV254 via plaque assays on LB agar plates.41 Samples were
116
stored on ice during the plaque assays. Following free chlorine and UV treatment, samples were
117
immediately stored at -80 °C prior to nucleic acid, protein, and lipid analyses.
118
Free chlorine experiments. Free chlorine was prepared by diluting NaClO stock solution
119
(Sigma-Aldrich) in PBS. At pH 7.4, HOCl and OCl— are equal in molar concentrations. Free
120
chlorine disinfection was conducted in a modified continuous quench-flow system that was
121
described previously for ozone reactions (Figure S2).42 In brief, free chlorine and Phi6 solutions
122
were continuously mixed in a PEEK micro static mixing tee (IDEX Health & Science) at flow
123
rates of 0.125 mL min-1 each to reach initial reaction conditions of 2 mg L-1 free chlorine as Cl2
124
and 4-5 × 1010 PFU mL-1 Phi6. The reacting mixture then passed through sample loops with varied
125
volumes to reach contact times of 0.3, 0.6, 2, 4, 8 and 11 s. The reactions were quenched with 550
126
mM Tris-HCl (pH 7.4) at a flow rate of 0.025 mL min-1. Control experiments demonstrated that
127
the addition of Tris-HCl as a quenching agent for free chlorine effectively halted Phi6 inactivation
128
(Figure S3). Approximately 2.4 mL of the quenched samples were collected for nucleic acid,
129
protein, and lipid analyses. After each experiment, the quench-flow system was thoroughly rinsed
130
with chlorine-demand-free water. Free chlorine concentrations in reaction solutions were
131
measured with the N,N-diethyl-p-phenylenediamine (DPD) ferrous titrimetric method and the
132
DPD colorimetric method according to the standard method.43 The percentage of free chlorine
ACS Paragon Plus Environment
6
Page 7 of 31
Environmental Science & Technology
133
consumed through the experiments was kept below 20% in order to maintain pseudo-first order
134
conditions. Negative controls for the free chlorine experiments were run in the continuous quench-
135
flow system in the same manner as the free chlorine samples, but with PBS rather than free
136
chlorine.
137
UV254 experiments. The UV254 experimental solutions consisted of 2.4 mL of Phi6 (4-5 × 1010
138
PFU mL-1) in PBS continuously stirred in 10 mL glass beakers. Samples were exposed to UV254 in
139
a collimated beam reactor44 with 0.16 mW cm-2 lamps (model G15T8, Philips) that were regularly
140
measured with chemical actinometry.45 The average UV254 intensity was corrected based on the
141
solution absorbance at UV254 and the sample depth. After correcting for shielding, the UV254
142
intensity was 0.14 mW cm-2. Samples were exposed to UV254 for 0, 5, 15, and 25 min, which
143
corresponded to UV254 doses of 0, 42, 130, 210 mJ cm-2. Negative controls for the UV254
144
experiments were prepared in the same manner as the experimental samples, but were stirred in
145
dark to capture any background virus inactivation and biomolecule reactions.
146
Virus inactivation kinetics by free chlorine and UV254 were calculated based on the Chick-
147
Watson model:46
148
𝐶 ln # & = −𝑘𝐷 𝐶%
149
where 𝐶 is the infectious titer (PFU mL-1), 𝐶% is the mean initial infectious titer (PFU mL-1), 𝑘 is
150
the inactivation rate constant (L mg-1 s-1 or cm2 mJ-1), and 𝐷 is the free chlorine concentration (mg
151
L-1) ´ contact time (s) or UV dose (mJ cm-2).
152
RT-qPCR assays. Following the UV254 and free chlorine reactions, the viral genomes were
153
extracted by QIAamp viral RNA mini kits (Qiagen). The Phi6 dsRNA genome consists of three
154
segments designated as small (S), medium (M), and large (L) based on their relative sizes. Three
155
primer sets for the Phi6 genome were designed and tested individually, each targeting a different
ACS Paragon Plus Environment
7
Environmental Science & Technology
Page 8 of 31
156
genome segment. The sum of the three amplicons (~1500 bp) covered approximately 10.5% of the
157
Phi6 genome (Table S1). The extracted viral genomes were mixed with 10 mM forward primer
158
and 10 mM reverse primer at a ratio of 10:1.5:1.5 (v/v/v) in Tris-EDTA buffer (10 mM Tris-HCl,
159
0.1 mM EDTA, pH 7.7), and then heated at 99 °C for 5 min, and quickly chilled on ice for 5 min
160
before mixing with RT-qPCR reagents. RT-qPCR reactions were prepared in 96-well plates
161
(Eppendorf) and conducted in duplicates on a Mastercycler ep RealPlex 2 system (Eppendorf) with
162
Gotaq OneStep RT-qPCR kits (Promega). The 20-µL RT-qPCR reactions consisted of 10 µL 2´
163
qPCR master mix, 0.4 µL 50´ RT mix, 5.2 µL template-primer mixture, 4 µL 5 M Betaine (Sigma-
164
Aldrich), and 0.4 µL nuclease-free water. The RT reaction was conducted at 40 °C for 15 min,
165
followed by an initial PCR activation step at 95 °C for 10 min. The PCR reaction included 40
166
cycles of DNA denaturation at 95 °C for 15 s, primer annealing at 59 °C for 30 s, and extension at
167
72 °C for 40 s. Melting curves were conducted by increasing the temperature from 60 °C to 95 °C
168
over 10 min. RNA standards used for the RT-qPCR calibration curves consisted of Phi6 genomes
169
extracted from the purified stock and quantified with a Qubit Fluorometer 2.0 (ThermoFisher
170
Scientific). The amplification efficiencies (mean ± standard deviation) of RT-qPCR reactions
171
targeting S, M, and L genome segment were 0.82 ± 0.10, 0.81 ± 0.05, and 0.81 ± 0.07, respectively.
172
The mean R2 were ≥ 0.99. The reaction kinetics of RT-qPCR target regions were modeled with
173
first-order reactions:
174
ln +
175
The reactions of the whole genome were predicted by extrapolating RT-qPCR results from the
176
~1500 bp covered by the three target regions:47
𝑁 . 0 = −𝑘1,. 𝐷 𝑁%,.
ACS Paragon Plus Environment
8
Page 9 of 31
177
Environmental Science & Technology
log4% #
∑.78,9,: 𝐿. 𝑁 𝑁 . &=+ 0 ? log4% + 0 ∑.78,9,: 𝐿;
295
0.05 for each ANCOVA comparison). When the RT-qPCR results were extrapolated to the entire
296
genome, the approximated reaction rate constant of the Phi6 genome (0.063 ± 0.012 cm2 mJ-1) was
297
not significantly different from the rate constant of Phi6 inactivation (0.067 ± 0.005 cm2 mJ-1) (P
298
> 0.05). This suggests that genome reactions drive UV254 inactivation of the enveloped virus Phi6.
299
Although this type of analysis has not been previously reported for enveloped viruses, our finding
300
is consistent with previous research on nonenveloped viruses.12,30,56,60 A comparison with the per
301
base reaction rate constants measured here with those reported previously suggests that the dsRNA
302
genome of Phi6 (2.4´ 10-6 cm2 mJ-1 base-1) are more resistant to UV254 than the dsDNA genome of
303
adenovirus (11 ´ 10-6 cm2 mJ-1 base-1)61 and the ssRNA genome of MS2 (24 ´ 10-6 cm2 mJ-1 base-
304
1
305
repaired by the host cell;12 a similar repair mechanism has not been reported for the RNA viruses.
306
We note that using RT-qPCR to estimate genome damage misses a fraction of the RNA
307
modifications that can be detected by mass spectrometry.44 Work on the photolysis of MS2 by
308
UV254, however, demonstrated that a single-hit inactivation model was appropriate for damage
309
detected with RT-qPCR; in other words, every modification in MS2 RNA that causes virus
310
inactivation can be detected by RT-qPCR.47 Our ongoing work aims to better characterize the
311
chemistry and biological impact of RNA and DNA modifications detected by reverse
312
transcriptases, polymerases, and mass spectrometry.
).56 It is worth noting that in the case of adenovirus, the modified bases detected by PCR can be
ACS Paragon Plus Environment
14
Page 15 of 31
Environmental Science & Technology
313
Reactions in Phi6 proteins. The Phi6 virion contains 11 distinct proteins that are assembled
314
into three layers, including viral membrane proteins (P3, P6, P9, P10, P13), nucleocapsid proteins
315
(P5, P8), and polymerase complex proteins (P1, P2, P4, P7) (Figure S6).38 The functions of these
316
proteins in the Phi6 life cycle have been reviewed in previous literature and are briefly described
317
in the SI (Figure S6).38 Our LC-MS/MS method was capable of detecting a total of 184 pairs of
318
14
319
and P2 (Figure S7). The repeated poor coverage of P6 and P2 was likely due to the low number of
320
P6 and P2 protein copies in the viral particles (Figure S7).
N- and 15N-labelled Phi6 peptides. Protein coverage was over 60% for all proteins except for P6
321
Free chlorine reactions. We tracked Phi6 protein degradation over the first 2-log10 Phi6
322
inactivation in order to model the peptide reactions with first-order kinetics. Free chlorine reacted
323
with all Phi6 peptides with reaction rate constants ranging from 0.41 to 6.3 L mg-1 s-1 (Figure 3;
324
Table S6). As expected, the most reactive peptides contained Met or Cys residues (Table S6).
325
Despite the similar reactivity of Met and Cys in the free amino acid form (Table S5), the most
326
reactive Cys-containing peptide C257-F267 in Phi6 P4 (2.8 ± 0.3 L mg-1 s-1) reacted slower than
327
the most reactive Met-containing peptide D448-R463 (6.3 ± 0.9 L mg-1 s-1) in Phi6 P1 (Table S6).
328
Furthermore, the rate constants of peptides containing Met varied. For example, in the Phi6 P1,
329
the rate constant of M198-K208 (1.1 ± 0.1 L mg-1 s-1) was approximately 3 ´ smaller than that of
330
peptide L53-Y66 (3.1 ± 0.5 L mg-1 s-1) and 4 ´ smaller than that of peptide M209-K215 (4.5 ± 0.7
331
L mg-1 s-1), despite the three peptides having spatially adjacent Met residues (Figure S8). The
332
variation in reactivity of peptides containing Met and Cys is likely related to the accessibility of
333
free chlorine to the amino acids.30 Indeed, the Cryo-EM model (PDB ID: 5muu) of Phi6 suggest
334
that in the P1 complex, the dimethyl sulfide of M198 in M198-K208 is protected by surrounding
335
amino acid residues, whereas the M65 in L53-Y66 and M209 in M209-K215 have higher solvent-
ACS Paragon Plus Environment
15
Environmental Science & Technology
Page 16 of 31
336
accessible surface areas (SASA, Figure S8). It is also worth noting that oxidized Met residues were
337
the only products in Phi6 proteins detected following 2-log10 inactivation by free chlorine (Figure
338
S9).
339
We initially hypothesized that the increased susceptibility of Phi6 to free chlorine inactivation
340
compared to nonenveloped viruses, such as MS2, was due to reactions in the membrane proteins.
341
These proteins play critical roles in the early steps of virus infection, and are located on the
342
outermost layer of the viral particle (Figure S6). In fact, our results showed that in Phi6, some
343
membrane proteins (e.g., P6, P9, P10, P13) reacted slower than the nucleocapsid proteins (e.g.,
344
P8) and polymerase proteins (e.g., P1, P2, P4) (Figure 3; Table S6). This suggests that free chlorine
345
molecules readily penetrate the lipid membrane and react with proteins in the nucleocapsid and
346
polymerase complex. Similar findings were reported in bacteria, where the non-dissociated HOCl
347
molecules could penetrate the negatively-charged bacterial membrane to react with intracellular
348
structures.62
349
The 8 most reactive peptides found in Phi6 proteins P3, P8, P1, P2, and P4 had rate constants
350
that were comparable to the Phi6 inactivation rate constant (Figure 4; Table S6), forming Met
351
oxidations as the main products (Figure S9). Consequently, one or several of these protein
352
reactions may drive Phi6 inactivation by free chlorine. Given the protein reactivity and the Phi6
353
life cycle, Phi6 inactivation may be due to the direct interruption of the ability to bind host cell
354
(P3) or to penetrate plasma membrane (P8).63,64 Alternatively, damage to proteins P2, P4, and P7
355
may indirectly inactivate Phi6 by causing changes in the vial structure.48,64,65
356
Peptides in Phi6 proteins were more reactive with free chlorine than peptides in the
357
nonenveloped MS2 proteins. The two most reactive peptides D448-R463 (6.3 ± 0.9 L mg-1 s-1) and
358
I678-R697 (5.9 ± 1.0 L mg-1 s-1) in Phi6 were approximately 150´ more reactive than the fastest
ACS Paragon Plus Environment
16
Page 17 of 31
Environmental Science & Technology
359
reacting peptide S373-R388 in the MS2 A protein (0.033 L mg-1 s-1).56 The marked discrepancies
360
in reactivity of Phi6 and MS2 peptides may be due to the relative solvent accessibilities of their
361
reactive amino acids.30 The average SASAs of the M456 and M680 residue in the Phi6 peptide are
362
95 Å2 and 77 Å2, respectively, as calculated by YASARA software.66 Unfortunately, the SASA
363
cannot be estimated for the Met in the most reactive MS2 peptide due to the fact that the crystal
364
structure of the MS2 A protein has not been resolved.
365
UV254 reactions. All Phi6 peptides reacted following UV254 exposure, but much less than they
366
reacted with free chlorine at the same levels of inactivation. Peptide concentrations decreased by
367
less than 50% following 4.2-log10 Phi6 inactivation (Figure 3), with rate constants ranging from
368
0.0009 to 0.0048 cm2 mJ-1 (Table S6). Similar reaction rate constants were reported for peptides
369
in bacteriophage MS2, fr, and GA proteins with UV254.30,56 Certain peptides in membrane protein
370
P3 and RNA polymerase P2 reacted with faster kinetics, likely due to the presence of one or more
371
UV-reactive amino acids in their sequences, including Trp (W), Tyr (Y), or Phe (F) (Table S6).67
372
Indirect photoreactions with nucleic acids may also play a role in the enhanced photoreactivity of
373
certain viral peptides as reported in MS2.68
374
Reactions in Phi6 lipids. Phi6 lipid membranes consist of glycerophospholipids, including
375
phosphatidylethanolamine (PE), phosphatidylglycerol (PG), and cardiolipin (CL) compounds at a
376
molar ratio of 58:38:4.39 Here, we measured the relative abundances of the eight most prevalent
377
PE and PG compounds in Phi6 membranes.
378
Free chlorine reactions. The PE and PG relative concentrations did not decrease significantly
379
over 9.1-log10 Phi6 inactivation by free chlorine (Figure S10; P > 0.05 for all tests). A number of
380
products were detected in the LC-MS spectra, including monochloramine products of PE
381
(16:0/16:1) and PE (18:1/16:1) (Figure 5). The peak intensities of PE monochloramine products
ACS Paragon Plus Environment
17
Environmental Science & Technology
Page 18 of 31
382
increased with increasing chlorine contact time, although at the highest inactivation level (i.e., 9.1-
383
log10 Phi6 inactivation), the product peak intensities were still three orders of magnitude smaller
384
than the parent PE peaks (Figure 5). The low PE monochloramine product concentration within
385
the Phi6 inactivation timeframe was not surprising given that the reported rate constant for this
386
reaction (1.8 ´ 104 M-1s-1) is three orders of magnitude lower than the rate constants for free
387
chlorine reacting with Met and Cys residues.69 Other lipid products were detected following free
388
chlorine treatment, with peak intensities no greater than 1% of the parent compound peak
389
intensities (Figure 5). The chemical compositions and structures of these products did not
390
correspond to commonly reported lipid oxidation products, such as lipid hydroperoxides and
391
chlorohydrins.70,71
392
UV254 reactions. Statistically significant reductions in the relative concentrations of the eight
393
major lipid compounds were not detected following UV254 doses resulting in 8.5-log10 Phi6
394
inactivation (Figure S10; P > 0.05 for all tests). Likewise, no major products were detected in the
395
LC-MS spectra of treated samples following UV254 treatment (Figure 5). Previous research on
396
UV254 reactions with the membrane of VSV suggest that the lipid envelope do not protect VSV
397
from inactivation.72
398
The lipid compositions of eukaryote enveloped viruses are more diverse than those of
399
bacteriophage Phi6. Influenza virus membranes, for example, contain not only PE and PG, but
400
also cholesterol and phosphatidylserine (PS).40 The kinetics of these lipids with HOCl, however,
401
are not markedly faster than the lipids in the Phi6 membrane.73,74 In summary, based on our Phi6
402
lipid results and what has been reported for other lipids found in virus membranes, we anticipate
403
that reactions in membrane lipids do not drive enveloped virus inactivation by free chlorine or
404
UV254.
ACS Paragon Plus Environment
18
Page 19 of 31
Environmental Science & Technology
405
Environmental implications. Enveloped viruses are often assumed to be more susceptible
406
than nonenveloped viruses to inactivation in the environment, but mechanistic descriptions of their
407
differing inactivation mechanisms are lacking in the literature. Our preliminary work with
408
enveloped virus Phi6 sheds light on how a model enveloped virus reacts with chemical oxidants
409
and UV radiation. We found that Phi6 was 30´ more susceptible to free chlorine inactivation than
410
the commonly studied nonenveloped virus MS2. Our work suggests that unlike MS2, the overall
411
Phi6 particle reactivity with free chlorine is driven more by protein reactions than by genome and
412
lipid reactions. Free chlorine reactions in the most reactive Phi6 peptides were orders of magnitude
413
faster than reactions in the most reactive MS2 peptides, specifically for Phi6 peptides that contain
414
solvent-accessible Met and Cys residues. Consequently, the relatively high number of solvent-
415
accessible Met and Cys residues in the Phi6 proteins may be responsible for its fast inactivation
416
kinetics with free chlorine. In contrast to chlorine, UV254 inactivates Phi6 primarily by reacting
417
with the genome. This is consistent with previous research on nonenveloped viruses. It is therefore
418
unlikely that enveloped viruses are more susceptible than nonenveloped viruses to direct
419
photolysis via sunlight or UV disinfection processes.
420
Looking beyond this initial comparison of enveloped Phi6 with nonenveloped MS2, this work
421
raises a number of hypotheses about virus reactivity and inactivation that can be tested with
422
additional viruses. For example, future work should explore whether proteins in enveloped viruses
423
are generally more susceptible to oxidants than proteins in nonenveloped viruses, and if this is the
424
reason that enveloped viruses tend to be more susceptible to inactivation by chemical oxidants.
425
Related to this, research should explore the link between the presence of solvent-accessible
426
reactive amino acids in viral proteins with virus inactivation by oxidants. UVC inactivation should
427
be tested with additional enveloped viruses that contain various genome sizes and genome types.
ACS Paragon Plus Environment
19
Environmental Science & Technology
Page 20 of 31
428
Possible enveloped viruses to study in the future include vesicular stomatitis virus and avian
429
influenza viruses. These are animal viruses with particle diameters and genome types that differ
430
from Phi6 and can be propagated to stocks with high titers. This last point is important for cases
431
in which researchers wish to apply the LC-MS/MS methods described in this study. Finally,
432
enveloped viruses in open air may undergo reactions and inactivation mechanisms similar to
433
viruses in water. Future studies should aim to compare aqueous virus reactivity with aerosolized
434
virus reactivity.
435
Enveloped viruses are structurally diverse, ranging in size, envelope composition, genome
436
type, and shape. These variations are likely reflected in a range of reactivities and inactivation
437
mechanisms. That being said, the structure and composition of the Phi6 are not especially unique
438
amongst the enveloped viruses. We are therefore confident that this study on Phi6 reactivity with
439
free chlorine and UV254 will be a valuable benchmark for future studies on enveloped virus fate in
440
disinfecting processes.
441 442
ACKNOWLEDGEMENTS
443
This study was funded by National Science Foundation (NSF) #1351188. YY was supported
444
through the Barbour Scholarship and Rackham International Student Fellowship at the University
445
of Michigan. We thank Dr. Michael Dodd at the University of Washington for his help with the
446
continuous quench-flow system, Dr. Rudy J. Richardson at the University of Michigan for his
447
instructions on how to use the YASARA software, and lab technician Tom Yavaraski for his efforts
448
to maintain the Q Exactive Orbitrap high resolution mass spectrometry.
449 450
SUPPORTING INFORMATION
ACS Paragon Plus Environment
20
Page 21 of 31
451
Environmental Science & Technology
The Supporting Information is available free of charge on the ACS Publications website.
452
Additional materials and methods on protein digestion, 15N-metabolic labelling, peptide
453
limit of quantification, lipid extraction; figures of SDS-PAGE of purified Phi6; data from
454
control experiment on Phi6 survival in Tris-HCl quenched chlorine solution; lab-scale
455
continuous flow quench system; lipid calibration curves; data from experiment on Phi6
456
resistance to free chlorine after storage; Phi6 structure; Phi6 protein coverage by LC-
457
MS/MS; Cryo-EM structure of Phi6 P1, relative abundances of peptides containing
458
methionine oxidations; relative abundances of Phi6 lipids following exposure to free
459
chlorine and UV254; tables of Phi6 primers and amplicon sizes; equipment settings for
460
peptide and lipid LC-MS/MS methods; reaction rate constants for Phi6 RT-qPCR regions
461
and entire genome by free chorine and UV254; the proportion of reactive bases in Phi6 and
462
MS2 genomes; the number of reactive amino acids in Phi6 proteins; Phi6 peptides and
463
reaction rate constants by free chlorine and UV254.
464 465 466 467 468
ACS Paragon Plus Environment
21
Environmental Science & Technology
FC
Contact time (s) 0.0 0.3 0.6
2
4
6
8
UV dose (mJ cm-2)
10 12
0
100
150
200
250
10-2
ns
10-3
C / C0
C / C0
469 470 471 472 473 474 475 476 477 478 479 480 481 482 483
100
10-1
ns
10-2
10-5
50
UV
100
10-1
10-4
Page 22 of 31
**
10-3 10-4 10-5
10-6
10-6
10-7
10-7
FC- or UV-treated φ6
Control
Figure 1. Inactivation of Phi6 by 2 mg L-1 free chlorine (FC) and UV254 (UV). Data includes n ³ 5 replicates for each chlorine contact time and n = 3 replicates for each UV254 dose. Student’s unpaired t-tests were used to determine statistical differences of Phi6 inactivation (C/C0) by free chlorine at two contact times. ** indicates P < 0.01, and thus that Phi6 inactivation was significantly different at the two time points; ns indicates Phi6 inactivation was not significantly different at the two time points (P > 0.05).
ACS Paragon Plus Environment
22
Page 23 of 31
Environmental Science & Technology
A
Contact time (s) 2
4
6
8
UV dose (mJ cm-2) 10
12
1.2 1.1 1.0 0.9 0.8 0.7 0.6 0.5 0.4
0
Ni / N0, i
Ni / N0, i
0
10-2
10-4
10-8
100
100
10-2
10-4
10-6
10-8
10-2
N / N0
N / N0
UV
C / C0 10-6
10-4
10-4 10-6
10-6
484 485 486 487 488 489 490 491 492
250
Regions on L
Regions on M
10-2
10-8
200
0.5
C / C0 100
150
0.3
Regions on S
100
100
0.6
0.4
FC
0.3
B
50
1.2 1.1 1.0 0.9 0.8 0.7
FC
1:1
10-8
UV
1: 1
Figure 2. Phi6 genome reactions when the viruses were reacted with 2 mg L-1 free chlorine (FC) and UV254 (UV). A: Reactions in three ~500 bp regions (Ni/N0,i) as measured by RT-qPCR with respect to chlorine contact time and UV254 doses. Data includes n ³ 2 replicates for each chlorine contact time and n = 3 replicates for each UV254 dose; B: Reactions in the entire Phi6 genome (N/N0). This data was extrapolated from the three RT-qPCR regions presented in A, and was reported with respect to virus inactivation (C/C0) as measured by plaque assays.
ACS Paragon Plus Environment
23
Environmental Science & Technology
mean log10 inactivation
0 mg s/L
0.6 FC mg s/L
1.2 mg s/L
0 mJ/cm2
43 UV mJ/cm2
130 mJ/cm2
0 (±0.04)
1.1 (±0.47)
2.3 (±0.41)
0 (±0.09)
1.7 (±0.07)
4.2 (±0.03)
Page 24 of 31
1.0
P3 0.8 Membrane P6 0.6
P9 P10 P13
P / P0
P8
0.4
Nucleocapsid P5
0.2
0
P1
Uncovered Peptide
Polymerase Complex
P2
P4
493 494 495 496 497 498 499
P7
Figure 3. Heatplot of Phi6 protein peptide reactions following Phi6 exposure to free chlorine (FC) and UV254 (UV). Each row in the heatplot represents one peptide. Peptides were arranged based on their sequential order in proteins, and the uncovered peptides are shown in grey. Peptide concentrations (P/P0) in this heatplot were averaged from 3 independent experiments. Detailed information of peptide sequences, reaction rate constants and standard errors are provided in Table S6.
ACS Paragon Plus Environment
24
Page 25 of 31
Environmental Science & Technology
C / C0 100
P / P0
100
10-1
10-2
10-3
Membrane
100
10-1
10-2
10-3
Nucleocapsid
100
10-1
10-2
10-3
Polymerase complex
10-1
10-2 53-66 LWEVGKGNIDPVMY (P1)
10-3 188-203 MDWEGSAVADAYAAIR (P3)
500 501 502 503 504 505 506 507 508 509 510 511 512
47-82 SNPVVAGLTLAQIGSTGYD AYQQLLENHPEVAEMLK (P8)
209-215 MLQATFK (P1) 448-463 DYALDRDPMVAIAALR (P1) 678-697 IEMIGTTGIGASAVHLAQSR (P1) 15-24 AQMLFANNIK (P2) 282-296 AADTHMPSMDRPTSM (P4)
Figure 4. Decay of the 8 most reactive Phi6 peptides (P/P0) by free chlorine with respect to virus inactivation (C/C0). Data below the LC-MS/MS limit of quantification is shown in grey.
ACS Paragon Plus Environment
25
Environmental Science & Technology
FC
UV 850
Control
800
800
750
750
m/z
700
700
650
650
600 850
Control
600 850
5
2.3-log10
6 7
800
1.8-log10
log10 (Peak Intensity)
m/z
850
800
750
m/z
m/z
8
750
700
700
650
650
600
600 850
5
9.1-log10
7
800 1
800
8
2
750
750
m/z
9 10 3
700
8.5-log10
6
m/z
850
Page 26 of 31
700
4
650
650
600
600 400
513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531
500
600
700
Retention time (seconds)
800
400
500
600
700
800
Retention time (seconds)
Figure 5. Phi6 lipids data collected by LC-MS before and after treatments of free chlorine (FC) and UV254 (UV). Arrows identify specific lipid products [M-H]- following free chlorine treatment, including the following accurate masses (1) 775.513; (2) 779.464; (3) 710.477; (4) 684.461; (5) 846.588; (6) 820.572; (7) 804.541; (8) 778.525; (9) 748.469 (monochloramine of PE(16:0/16:1)); (10) 722.454 (monochloramine of PE(18:1/16:1)).
ACS Paragon Plus Environment
26
Page 27 of 31
532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576
Environmental Science & Technology
REFERENCES (1) Pica, N.; Bouvier, N. M. Environmental factors affecting the transmission of respiratory viruses. Curr. Opin. Virol. 2012, 2 (1), 90–95. (2) Wigginton, K. R.; Ye, Y.; Ellenberg, R. M. Emerging investigators series: The source and fate of pandemic viruses in the urban water cycle. Environ. Sci.: Water Res. Technol. 2015, 1, 735–746. (3) Osterholm, M. T.; Moore, K. A.; Kelley, N. S.; Brosseau, L. M.; Wong, G.; Murphy, F. A.; Peters, C. J.; LeDuc, J. W.; Russell, P. K.; Van Herp, M.; et al. Transmission of Ebola viruses: What we know and what we do not know. mBio 2015, 6 (2), 1–9. (4) Memarzadeh, F. Literature review of the effect of temperature and humidity on viruses. ASHRAE Trans. 2012, 118, 1049–1060. (5) Welliver, R. C. Temperature, humidity, and ultraviolet B radiation predict community respiratory syncytial virus activity. Pediatr. Infect. Dis. J. 2007, 26, S29–S35. (6) Casanova, L. M.; Jeon, S.; Rutala, W. A.; Weber, D. J.; Sobsey, M. D. Effects of air temperature and relative humidity on coronavirus survival on surfaces. Appl. Environ. Microbiol. 2010, 76 (9), 2712–2717. (7) Songer, J. R. Influence of relative humidity on the survival of some airborne viruses. Appl. Microbiol. 1967, 15 (1), 35–42. (8) Weber, T. P.; Stilianakis, N. I. A note on the inactivation of influenza A viruses by solar radiation, relative humidity and temperature. Photochem. Photobiol. 2008, 84 (6), 1601– 1602. (9) Yang, W.; Elankumaran, S.; Marr, L. C. Relationship between humidity and influenza A viability in droplets and implications for influenza’s seasonality. PLoS ONE 2012, 7 (10), e46789. (10) Chumpolbanchorn, K.; Suemanotham, N.; Siripara, N.; Puyati, B.; Chaichoune, K. The effect of temperature and UV light on infectivity of avian influenza virus (H5N1, Thai field strain) in chicken fecal manure. Southeast Asian J. Trop. Med. Public Health 2006, 37 (1), 102–105. (11) Sagripanti, J. L.; Lytle, C. D. Inactivation of influenza virus by solar radiation. Photochem. Photobiol. 2007, 83 (5), 1278–1282. (12) Bosshard, F.; Bosshard, F.; Armand, F.; Armand, F.; Hamelin, R.; Hamelin, R.; Kohn, T. Mechanisms of human adenovirus inactivation by sunlight and UVC light as examined by quantitative PCR and quantitative proteomics. Appl. Environ. Microbiol. 2012, 79 (4), 1325–1332. (13) Ehrlich, R.; Miller, S. Effect of NO2 on airborne Venezuelan equine encephalomyelitis virus. Appl. Microbiol. 1972, 23 (3), 481–484. (14) Sobsey, M. D.; Meschke, J. S. Virus survival in the environment with special attention to survival in sewage droplets and other environmental media of fecal or respiratory origin. http://www.unc.edu.proxy.lib.umich.edu/courses/2008spring/envr/421/001/WHO_VirusS urvivalReport_21Aug2003.pdf. (15) Wigginton, K. R.; Kohn, T. Virus disinfection mechanisms: The role of virus composition, structure, and function. Curr. Opin. Virol. 2012, 2 (1), 84–89. (16) Ye, Y.; Ellenberg, R. M.; Graham, K. E.; Wigginton, K. R. Survivability, partitioning, and recovery of enveloped viruses in untreated municipal wastewater. Environ. Sci. Technol. 2016, 50, 5077–5085.
ACS Paragon Plus Environment
27
Environmental Science & Technology
577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622
(17) (18) (19) (20) (21) (22) (23) (24) (25) (26) (27) (28) (29) (30) (31)
(32) (33) (34)
Page 28 of 31
Casanova, L. M.; Weaver, S. R. Inactivation of an enveloped surrogate virus in human sewage. Environ. Sci. Technol. Lett. 2015, 2, 76–78. Bibby, K.; Fischer, R.; Casson, L.; Stachler, E. Persistence of Ebola virus in sterilized wastewater. Environ. Sci. Technol. Lett. 2015, 2, 245–249. Gallandat, K.; Lantagne, D. Selection of a Biosafety Level 1 (BSL-1) surrogate to evaluate surface disinfection efficacy in Ebola outbreaks: Comparison of four bacteriophages. PLoS ONE 2017, 12 (5), 1–10. Rabenau, H. F.; Cinatl, J.; Morgenstern, B.; Bauer, G.; Preiser, W.; Doerr, H. W. Stability and inactivation of SARS coronavirus. Med. Microbiol. Immunol. 2005, 194 (12), 1–6. Chan, K. H.; Poon, L. L. L. M.; Cheng, V. C. C.; Guan, Y.; Hung, I. F. N.; Kong, J.; Yam, L. Y. C.; Seto, W. H.; Yuen, K. Y.; Peiris, J. S. M. Detection of SARS coronavirus in patients with suspected SARS. Emerg. Infect. Dis. 2004, 10 (2), 294–299. Yu, I. T. S.; Li, Y.; Wong, T. W.; Tam, W.; Chan, A. T.; Lee, J. H. W.; Leung, D. Y. C.; Ho, T. Evidence of airborne transmissionof the severe acute respiratory syndrome virus. N. Engl. J. Med. 2004, 350, 1731–1739. Tellier, R. Review of aerosol transmission of influenza A virus. Emerg. Infect. Dis. 2006, 12 (11), 1657–1662. Bean, B.; Moore, B. M.; Sterner, B.; Peterson, L. R.; Gerding, D. N.; Balfour, H. H. Survival of influenza viruses on environmental surfaces. J. Infect. Dis. 1982, 146 (1), 47–51. Webster, R. G. Influenza: an emerging disease. Emerg. Infect. Dis. 1998, 4 (3), 436–441. Stallknecht, D. E.; Goekjian, V. H.; Wilcox, B. R.; Poulson, R. L.; Brown, J. D. Avian influenza virus in aquatic habitats: what do we need to learn? Avian Dis. 2010, 54 (s1), 461–465. Albina, E. Epidemiology of porcine reproductive and respiratory syndrome (PRRS): An overview. Veterinary microbiol. 1997, 55, 309–316. Piercy, T. J.; Smither, S. J.; Steward, J. A.; Eastaugh, L.; Lever, M. S. The survival of filoviruses in liquids, on solid substrates and in a dynamic aerosol. J. Appl. Microbiol. 2010, 109 (5), 1531–1539. Bibby, K.; Aquino de Carvalho, N.; Rule Wigginton, K. Research needs for wastewater handling in virus outbreak response. Environ. Sci. Technol. 2017, 51, 2534–2535. Sigstam, T.; Gannon, G.; Cascella, M.; Pecson, B. M.; Wigginton, K. R.; Kohn, T. Subtle differences in virus composition affect disinfection kinetics and mechanisms. Appl. Environ. Microbiol. 2013, 79 (11), 3455–3467. Gall, A. M.; Shisler, J. L.; Mariñas, B. J. Characterizing bacteriophage PR772 as a potential surrogate for adenovirus in water disinfection: A comparative analysis of inactivation kinetics and replication cycle inhibition by free chlorine. Environ. Sci. Technol. 2016, 50 (5), 2522–2529. Lee, M. T.; Pruden, A.; science, L. M. E.; 2016. Partitioning of viruses in wastewater systems and potential for aerosolization. J. Chem. Eng. 2016, 3 (5), 210–215. Lin, K.; Marr, L. C. Aerosolization of Ebola virus surrogates in wastewater systems. Environ. Sci. Technol. 2017, 51 (5), 2669–2675. Wolfe, M. K.; Gallandat, K.; Daniels, K.; Desmarais, A. M.; Scheinman, P.; Lantagne, D. Handwashing and Ebola virus disease outbreaks: A randomized comparison of soap, hand sanitizer, and 0.05% chlorine solutions on the inactivation and removal of model
ACS Paragon Plus Environment
28
Page 29 of 31
623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668
Environmental Science & Technology
(35) (36) (37)
(38) (39) (40)
(41) (42)
(43) (44) (45) (46) (47) (48) (49) (50)
organisms Phi6 and E. coli from hands and persistence in rinse water. PLoS ONE 2017, 12 (2), e0172734. Aquino de Carvalho, N.; Stachler, E. N.; Cimabue, N.; Bibby, K. Evaluation of Phi6 persistence and suitability as an enveloped virus surrogate. Environ. Sci. Technol. 2017, 51 (15), 8692–8700. Gallandat, K.; Wolfe, M. K.; Lantagne, D. Surface cleaning and disinfection: Efficacy assessment of four chlorine types using escherichia coli and the Ebola surrogate Phi6. Environ. Sci. Technol. 2017, 51 (8), 4624–4631. Cytoviridae. Virus Taxonomy: Ninth Report of the International Committee on Taxonomy of Viruses; King, A. M. Q., Adams, M. J., Carstens, E. B., Lefkowitz, E. J., Eds.; Elsevier: Oxford, 2011; pp 515–518. Poranen, M. M.; Tuma, R.; Bamford, D. H. Assembly of double-stranded RNA bacteriophages. Adv. Virus Res. 2005, 64, 15–43. Laurinavičius, S.; Käkelä, R.; Bamford, D. H.; Somerharju, P. The origin of phospholipids of the enveloped bacteriophage Phi6. Virology 2004, 326 (1), 182–190. Gerl, M. J.; Sampaio, J. L.; Urban, S.; Kalvodova, L.; Verbavatz, J.-M.; Binnington, B.; Lindemann, D.; Lingwood, C. A.; Shevchenko, A.; Schroeder, C.; et al. Quantitative analysis of the lipidomes of the influenza virus envelope and MDCK cell apical membrane. J. Cell Biol. 2012, 196 (2), 213–221. Bamford, D. H.; Ojala, P. M.; Frilander, M.; Walin, L.; Bamford, J. K. H. Isolation, purification, and function of assembly intermediates and subviral particles of bacteriophages PRD1 and Phi6. Methods Mol. Genet. 1995, 6, 455–474. Dodd, M. C.; Vu, N. D.; Ammann, A.; Le, V. C.; Kissner, R.; Pham, H. V.; Cao, T. H.; Berg, M.; Gunten, von, U. Kinetics and mechanistic aspects of As(III) oxidation by aqueous chlorine, chloramines, and ozone: Relevance to drinking water treatment. Environ. Sci. Technol. 2006, 40 (10), 3285–3292. Standard Methods for Examination of Water & Wastewater, 20 ed.; Clescerl, L. S., Greenberg, A. E., Eaton, A. D., Eds.; American Public Health Assocaition: Washington, DC, 1999. Qiao, Z.; Wigginton, K. R. Direct and indirect photochemical reactions in viral RNA measured with RT-qPCR and mass spectrometry. Environ. Sci. Technol. 2016, 50 (24), 13371–13379. Rahn, R. O. Potassium iodide as a chemical actinometer for 254 nm radiation: Use of iodate as an electron scavenger. Photochem. Photobiol. 1997, 66 (4), 450–455. Gyürék, L. L.; Finch, G. R. Modeling water treatment chemical disinfection kinetics. J. Environ. Eng. 1998, 124 (9), 783–793. Pecson, B. M.; Ackermann, M.; Kohn, T. Framework for using quantitative PCR as a nonculture based method to estimate virus infectivity. Environ. Sci. Technol. 2011, 45 (6), 2257–2263. Choe, J. K.; Richards, D. H.; Wilson, C. J.; Mitch, W. A. Degradation of amino acids and structure in model proteins and bacteriophage MS2 by chlorine, bromine, and ozone. Environ. Sci. Technol. 2015, 49 (22), 13331–13339. Goshe, M. B.; Smith, R. D. Stable isotope-coded proteomic mass spectrometry. Curr. Opin. Biotechnol. 2003, 14, 101–109. Gleit, A. Estimation for small normal data sets with detection limits. Environ. Sci. Technol. 1985, 19 (12), 1201–1206.
ACS Paragon Plus Environment
29
Environmental Science & Technology
669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713
(51) (52)
(53) (54) (55) (56) (57) (58) (59) (60) (61)
(62) (63)
(64) (65)
Page 30 of 31
Matyash, V.; Liebisch, G.; Kurzchalia, T. V.; Shevchenko, A.; Schwudke, D. Lipid extraction by methyl-tert-butyl ether for high-throughput lipidomics. J. Lipid Res. 2008, 49 (5), 1137–1146. Herzog, R.; Schwudke, D.; Schuhmann, K.; Sampaio, J. L.; Bornstein, S. R.; Schroeder, M.; Andrej Shevchenko. A novel informatics concept for high-throughput shotgun lipidomics based on the molecular fragmentation query language. Genome Biol. 2011, 12, 1–25. Kahler, A. M.; Cromeans, T. L.; Metcalfe, M. G.; Humphrey, C. D.; Hill, V. R. Aggregation of adenovirus 2 in source water and impacts on disinfection by chlorine. Food Environ. Virol. 2016, 8 (2), 148–155. Gerba, C. P.; Betancourt, W. Q. Viral aggregation: Impact on virus behavior in the environment. Environ. Sci. Technol. 2017, 51 (13), 7318–7325. Sigstam, T.; Rohatschek, A.; Zhong, Q.; Brennecke, M.; Kohn, T. On the cause of the tailing phenomenon during virus disinfection by chlorine dioxide. Water Res. 2014, 48, 82–89. Wigginton, K. R.; Pecson, B. M.; Sigstam, T.; Bosshard, F.; Kohn, T. Virus inactivation mechanisms: Impact of disinfectants on virus function and structural integrity. Environ. Sci. Technol. 2012, 46 (21), 12069–12078. Powell, W. F.; Setlow, R. B. The effect of monochromatic ultraviolet radiation on the interfering property of influenza virus. Water Res. 1956, 2, 337–343. Bay, P. H.; Reichmann, M. E. UV inactivation of the biological activity of defective interfering particles generated by vesicular stomatitis virus. J. Virol. 1979, 32 (3), 876– 884. Battigelli, D. A.; Sobesey, M. D.; Lobe, D. C. The inactivation of hepatitis A virus and other model viruses by UV irradiation. Water Sci. Technol. 1993, 27, 339–342. Simonet, J.; Gantzer, C. Inactivation of poliovirus 1 and F-specific RNA phages and degradation of their genomes by UV irradiation at 254 nanometers. Appl. Environ. Microbiol. 2006, 72 (12), 7671–7677. Beck, S. E.; Rodriguez, R. A.; Linden, K. G.; Hargy, T. M.; Larason, T. C.; Wright, H. B. Wavelength dependent UV inactivation and DNA damage of adenovirus as measured by cell culture infectivity and long range quantitative PCR. Environ. Sci. Technol. 2013, 48 (1), 591–598. Dodd, M. C. Potential impacts of disinfection processes on elimination and deactivation of antibiotic resistance genes during water and wastewater treatment. J. Environ. Monit. 2012, 14, 1754–1771. Lewis, A. K.; Dunleavy, K. M.; Senkow, T. L.; Her, C.; Horn, B. T.; Jersett, M. A.; Mahling, R.; McCarthy, M. R.; Perell, G. T.; Valley, C. C.; et al. Oxidation increases the strength of the methionine-aromatic interaction. Nat. Chem. Biol. 2016, 12 (10), 860– 866. Ogata, N. Inactivation of influenza virus haemagglutinin by chlorine dioxide: oxidation of the conserved tryptophan 153 residue in the receptor-binding site. J. Gen. Virol. 2012, 93, 2558–2563. Liu, D.; Ren, D.; Huang, H.; Dankberg, J.; Rosenfeld, R.; Cocco, M. J.; Li, L.; Brems, D. N.; Remmele, R. L. Structure and stability changes of human IgG1 Fc as a consequence of methionine oxidation. Biochemistry 2008, 47 (18), 5088–5100.
ACS Paragon Plus Environment
30
Page 31 of 31
714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734
Environmental Science & Technology
(66) (67) (68) (69) (70) (71) (72) (73) (74)
Krieger, E.; Vriend, G. New ways to boost molecular dynamics simulations. J. Comput. Chem. 2015, 36 (13), 996–1007. Mihalyi, E. Numerical values of the absorbances of the aromatic amino acids in acid, neutral, and alkaline solutions. J. Chem. Eng. 1968, 13, 179–182. Wigginton, K. R.; Menin, L.; Sigstam, T.; Gannon, G.; Cascella, M.; Hamidane, H. B.; Tsybin, Y. O.; Waridel, P.; Kohn, T. UV radiation induces genome-mediated, sitespecific cleavage in viral proteins. ChemBioChem 2012, 13 (6), 837–845. Pattison, D. I.; Davies, M. J. Reactions of myeloperoxidase-derived oxidants with biological substrates: Gaining chemical insight into human inflammatory diseases. Curr. Med. Chem. 2006, 13, 3271–3290. Spickett, C. M. Chlorinated lipids and fatty acids: An emerging role in pathology. Pharmacol. Ther. 2007, 115 (3), 400–409. Frankel, E. N. Lipid oxidation: Mechanisms, products and biological significance. J. Am. Oil. Chem. Soc. 1984, 61 (12), 1908–1917. Anderson, R.; Daya, M.; Reeve, J. An evaluation of the contribution of membrane lipids to protection against ultraviolet radiation. Adv. Virus Res. 1987, 905, 227–230. Ghanbari, H. A.; Wheeler, W. B.; Kirk, J. R. Reactions of aqueous chlorine and chlorine dioxide with lipids: Chlorine incorporation. J. Food Sci. 1982, 47, 482–485. Carr, A. C.; van den Berg, J. J. M.; Winterbourn, C. C. Chlorination of cholesterol in cell membranes by hypochlorous acid. Arch. Biochem. Biophys. 1996, 332 (1), 63–69.
ACS Paragon Plus Environment
31