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Isolation and Characterization of Lactoferrin Peptides with Stimulatory Effect on Osteoblast Proliferation Fengjiao Fan, Maolin Tu, Meng Liu, Pujie Shi, Yun Wang, Di Wu, and Ming Du J. Agric. Food Chem., Just Accepted Manuscript • Publication Date (Web): 21 Jul 2017 Downloaded from http://pubs.acs.org on July 21, 2017
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Journal of Agricultural and Food Chemistry
Isolation and Characterization of Lactoferrin Peptides with Stimulatory Effect on Osteoblast Proliferation
Fengjiao Fana, Maolin Tua, Meng Liua, Pujie Shia, Yun Wanga, Di Wub, Ming Dub,*
a
Department of Food Science and Engineering, Harbin Institute of Technology, Harbin 150090, China;
b
School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, China.
*
Corresponding author: Tel: +86-411-86332275; Fax: +86-411-86323262; E-mail:
[email protected].
1
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ABSTRACT Lactoferrin is reported to be a potential food protein with osteogenic
2
activity. However, the activity of lactoferrin peptides is questionable. In the present
3
study, we isolated and characterized peptides from lactoferrin with stimulatory effect
4
on osteoblast proliferation. Peptides from the lactoferrin pepsin hydrolysate were
5
purified using cation-exchange and gel-filtration chromatography. Effects of different
6
hydrolysates and peptides on the proliferation of osteoblast MC3T3-E1 cells were
7
compared by MTT assay. Results showed that fraction P5-a from Superdex Peptide
8
10/300 GL gel chromatography showed better activity. Tricine-sodium dodecyl sulfate
9
polyacrylamide gel electrophoresis (Tricine-SDS-PAGE) and high-performance liquid
10
chromatography coupled to electrospray ionization tandem mass spectrometry
11
(HPLC-ESI–MS/MS) confirmed that two peptides components of P5-a corresponded
12
to fractions of 20-78 and 191-277 amino acids in Bos taurus lactoferrin molecule (GI:
13
221706349). These results will provide some theoretical and practical data for the
14
preparation and application of osteogenic peptides in functional food industry.
15
KEYWORDS:
16
Proliferation of osteoblast, HPLC-ESI–MS/MS
Lactoferrin,
Peptides,
Enzymatic
hydrolysis,
2
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INTRODUCTION
18
Bone remodeling, an ongoing process in skeletal tissue at all stages of life,
19
involves bone formation by osteoblasts and bone resorption by osteoclasts. During the
20
biological process of bone remodeling, an imbalance wherein bone resorption
21
predominates over bone formation will result in osteoporosis. Osteoporosis,
22
characterized by reduced bone mineral density (BMD), is one of the major public health
23
problems that enhance susceptibility to bone fractures and affect more than 200 million
24
people.1,2 Osteoblast plays an important role in bone rebuilding; hence, proteins with
25
osteogenic activity are attracting more attention owing to the prevalence and importance
26
of osteoporosis.
27
Bone morphogenetic proteins (BMPs) are members of the transforming growth
28
factor-β superfamily, known to induce the formation of bone and cartilage in vivo.3 The
29
most widely studied BMPs are BMP-2, BMP-3 (osteogenin), BMP-4, and BMP-7
30
(osteogenic protein-1). A synthetic peptide derived from BMP-2 is reported to induce
31
ectopic bone formation and promote repair of tibial bone defects.4,5
32
Studies have shown that lactoferrin, bovine angiogenin, and lactoperoxidase—the
33
three components of milk basic protein—modulate bone metabolism,6 stimulate
34
osteoblast proliferation and collagen production, and suppress osteoclast activity.7-9
35
Lactoferrin is a multi-functional protein from various secretions of organisms and has
36
been associated with almost 20 different physiological functions10 such as antimicrobial,
37
antitumor, antioxidative, osteogenic, and immunoregulatory activities.11-13 In recent
38
years, studies have highlighted the osteogenic activity of lactoferrin; Lactoferrin 3
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improved BMD of C3H-ovariectomized mice and stimulated growth of osteoblastic
40
cells while inhibiting preosteoclastic cell growth in vitro.14 In addition, it acted as a
41
growth factor and showed in vitro and in vivo anabolic activity in bone.15-17 The
42
mitogen-activated protein kinase (MAPK) and osteoprotegerin (OPG)/receptor activator
43
of nuclear factor kappa-B ligand (RANKL)/receptor activator of nuclear factor kappa-B
44
(RANK) signaling pathways were involved in the effects of lactoferrin on bone
45
metabolism.18-20
46
Lactoferricin, a peptide derived from the N-terminal region of lactoferrin (fraction
47
17-41) has been reported to exhibit bactericidal activity higher than that of
48
lactoferrin.21,22 Some pepsin-digested bovine lactoferrin peptides showed antitumor
49
activity against human oral squamous cell carcinoma and murine tumor.23,24 In addition,
50
some lactoferrin peptides (< 3 kD) displayed antihypertensive effect and lowered blood
51
pressure in spontaneously hypertensive rats.25,26 Studies have shown that oral
52
administration of lactoferrin results in its degradation into bioactive peptides.27,28
53
However, very few studies have focused on the osteogenic activity of lactoferrin
54
peptides, thereby limiting their applications.
55
The objective of the present study was to isolate and identify peptides with
56
stimulatory effect on osteoblast proliferation from the pepsin hydrolysate of lactoferrin
57
using column chromatography and high-performance liquid chromatography (HPLC)
58
coupled to electrospray ionization tandem mass spectrometry (ESI-MS/MS). The select
59
peptides can be used as potential health-promoting functional foods for prevention of
60
osteoporosis. 4
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MATERIALS AND METHODS
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Cell Line and Materials
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MC3T3-E1 cells purchased from the Cell Bank of Chinese Academy of Sciences
64
(Shanghai, China) were cultured in α-modified Eagle’s medium (α-MEM) containing
65
10% fetal bovine serum (FBS) and 1% penicillin-streptomycin (HyClone, Logan, UT,
66
USA).
67
Bovine lactoferrin (95.41% purity) used in this study was obtained from New
68
Zealand. Pepsin (EC 3.4.23.1, 1:3000) was purchased from AMRESCO (Cleveland, OH,
69
USA). SP Sepharose Fast Flow and Superdex Peptide 10/300 GL were supplied by GE
70
Healthcare (Beijing, China). All other reagents used were of analytical grade.
71
Preparation of Crude Peptides
72
Lactoferrin was dissolved in distilled deionized water at 5% (W/V), while pepsin
73
was dissolved at a concentration of 26.125 mg/L in 150 mM sodium chloride
74
(NaCl)/hydrochloric (HCl, pH 2.0). The pepsin solution (912 mL) was pre-warmed to
75
37 °C and mixed with 48 mL lactoferrin solution to initiate hydrolysis at 37 °C for
76
0-240 min. The ratio of pepsin to lactoferrin was 238 U/g. Aliquots of 50 mL of
77
pepsin-digested lactoferrin were taken at 5, 10, 30, 60, 90, 120, 180, and 240 min and
78
treated with 25 mL sodium bicarbonate (NaHCO3, 25 mM) to terminate the reaction in
79
an ice bath and the corresponding lactoferrin hydrolysates (LFH) were named as LFH5,
80
LFH10, LFH30, LFH60, LFH90, LFH120, LFH180, and LFH240, respectively.
81
Supernatants were separated by centrifugation for 10 min at 16000 ×g and the crude
82
peptides were obtained by dialysis with 3 kD cut-off membrane for complete removal of 5
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salt.
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Purification of Peptides
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Lactoferrin hydrolysate with highest stimulatory activity on osteoblast proliferation
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(LFH5) was filtered using a 0.22 µm syringe filter and loaded onto an SP Sepharose
87
Fast Flow column (1.6 cm × 10 cm) pre-equilibrated with 0.05 mol/L
88
phosphate-buffered saline (PBS, pH 7.4) buffer. Elution was performed using 0.05
89
mol/L PBS buffer (pH 7.4) and 0.05 mol/L PBS buffer (with 1 mol/L NaCl, pH 7.4) as
90
mobile phase at a flow rate of 3 mL/min. Elution was operated at 4 °C and monitored at
91
280 nm wavelength. All peaks were analyzed for their effect on osteoblast proliferation.
92
The peak with the strongest activity was freeze-dried and loaded onto a Superdex
93
Peptide 10/300 GL column (1.0 cm × 300 mm). The column was equilibrated and eluted
94
with 0.02 mol/L PBS buffer (pH 7.6) at a flow rate of 0.5 mL/min. Elution was operated
95
at 4 °C and monitored at 280 nm wavelength. All fractions were analyzed for their
96
molecular masses and effects on osteoblast proliferation. The peak with the strongest
97
activity was freeze-dried and subjected to HPLC-ESI–MS/MS for the determination of
98
purified peptide sequence.
99
Sodium
100
Dodecyl
Sulfate
Polyacrylamide
Gel
Electrophoresis
(SDS-PAGE) Analysis
101
Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was
102
carried out in a modified Laemmli system to investigate purity and molecular masses of
103
peptides using 5% and 12% acrylamide in stacking and separating gels, respectively.29
104
Protein bands were visualized by staining with Coomassie R250 brilliant blue. Standard 6
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proteins (Thermo Scientific, Waltham, MA, USA) used for molecular mass
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determination were as follows: β-galactosidase (116 kD), bovine serum albumin (66.2
107
kD), ovalbumin (45 kD), lactate dehydrogenase (35 kD), REase Bsp981 (25 kD),
108
β-lactoglobulin (18.4 kD), and lysozyme (14.4 kD). Gels were scanned using Bio-Rad
109
Gel Doc XR system (Bio-Rad, Hercules, CA, USA) and analyzed by Quantity One
110
software Version 4.6.2 (Bio-Rad). Tricine–SDS-PAGE was preferred electrophoretic
111
system for separation of low molecular mass proteins.30 We selected 4% stacking and
112
16% separating gels according to the method used by Hermann Schägger.31 Low-range
113
protein marker (Thermo Scientific) used was a mixture of six recombinant proteins and
114
synthetic peptides (1.7 to 42 kD).
115
Cell Viability Assay
116
The
proliferation
activity
of
osteoblast
tetrazolium
was
measured
bromide
(MTT)
by
3-(4,
method.32,33
117
5-dimethylthiazol-2-yl)-2,5-diphenyl
118
MC3T3-E1 cells (l × 104 cells) were seeded in a 96-well plate and cultured in α-MEM
119
medium containing 10% FBS for 24 h in a humidified atmosphere of 5% CO2 at 37 °C.
120
Following incubation, the medium was dispensed and cells were washed with 0.01
121
mol/L PBS buffer (pH 7.2). Cells were further incubated for 24, 48, and 72 h at 37 °C in
122
presence of 95 µL α-MEM and 5 µL sample, followed by treatment with MTT solution
123
(0.5 mg/mL in PBS). After 4 h, the medium was removed and 150 µL of dimethyl
124
sulfoxide (DMSO) was added to dissolve MTT formazan crystals by shaking for 10 min.
125
The absorbance was measured at 490 nm wavelength on a microplate reader (Eon,
126
BioTek, USA). 7
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Enzymatic Hydrolysis of Isolated Peptides by Trypsin
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The lyophilized powder (about 30 µg) of the isolated peptide with the strongest
129
activity (named P5-a under Results and Discussion) was solubilized in 30 µL SDT
130
buffer(4% SDS, 100 mM dithiothreitol [DTT], and 150 mM Tris-HCl pH 8.0)at 90 °C
131
for 5 min. SDS, DTT, and other low molecular weight components were removed using
132
200 µL UA buffer (8 M urea and 150 mM Tris-HCl pH 8.0) by repeated ultrafiltration
133
(Microcon units, 30 kD). The retentate was treated with 100 µL of 0.05 M
134
iodoacetamide in UA buffer for 30 min in darkness. The filter was washed three times
135
with 100 µL UA buffer and treated twice with 100 µL ammonium bicarbonate
136
(NH4HCO3, 25 mM). The protein suspension was digested with 2 µg trypsin in 40 µL
137
NH4HCO3 (25 mM) overnight at 37 °C and the resulting peptides were collected as a
138
filtrate.34
139
Identification of Peptides by HPLC-ESI–MS/MS
140
The peptides of P5-a were identified by HPLC-ESI–MS/MS with some
141
modification in the method described by Xie.35 Chromatography was performed using
142
an Easy nLC system (Thermo Scientific). A sample volume of 6 µL was injected for
143
nanoLC-MS/MS analysis. Buffer A (0.1% formic acid in water) and buffer B (80%
144
acetonitrile and 0.1% formic acid) were used as mobile phases for gradient separation.
145
The column was equilibrated with 95% buffer A before sample injection, and samples
146
were automatically loaded onto a C18-reversed phase column (2 cm × 100 µm, 5 µm
147
resin, Thermo scientific) and eluted onto a C18-reversed phase analytical column (75
148
µm × 100 mm, 3 µm resin, Thermo Scientific). A 60-min gradient was run as follows: 8
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50 min from 4% to 50% B, 4 min linear gradient to 100% B, and 6 min at 100% B.
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Peptides eluted from the C18 column were pumped through a capillary tip for
151
electrospray and analyzed by a Q-Exactive mass spectrometer (Thermo Scientific). Full
152
scans were acquired in Orbitrap mass analyzer over m/z 300-1800 range with resolution
153
of 70,000. Normalized collision energy was 30 eV and the underfill ratio was defined as
154
0.1%. The instrument was run with peptide recognition mode enabled. Data were
155
acquired using a data-dependent top10 method dynamically choosing the most abundant
156
precursor ions. Mascot 2.2 was used for searching against corresponding database.
157
Statistical Analysis
158
Data represent results of three independent experiments each performed in
159
triplicate and are expressed as mean ± standard deviation (SD). Statistical analyses were
160
performed using the statistical software package SPSS 19.0. One-way analysis of
161
variance (ANOVA) was employed to determine the significant difference between the
162
means at p < 0.05.
163
RESULTS AND DISCUSSION
164
Preparation of Lactoferrin Hydrolysates with Pepsin Digestion
165
Peptides from lactoferrin were obtained after hydrolysis with pepsin for 5-240 min.
166
Different digestion time resulted in different protein degradation profiles, owing to
167
differences in the degree of hydrolysis. As shown in Figure 1A, pepsin at pH 2.0
168
showed significant effects on the proteolysis of lactoferrin; no intact lactoferrin was
169
detected in all hydrolysates, as analyzed by SDS-PAGE. An increase in hydrolysis time
170
resulted in gradual lysis of lactoferrin into peptides with low molecular weight. This 9
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observation is in line with a previous study reporting only 6% intact lactoferrin after
172
10-min treatment and no intact lactoferrin after 30-min treatment with porcine pepsin
173
A .36 Small differences observed may be attributed to various experimental conditions
174
and enzymes sources. After 90 min of hydrolysis, hydrolysate profiles were unchanged.
175
As molecular masses of peptides in all hydrolysates were less than 14.4 kD,
176
Tricine-SDS-PAGE analysis was performed. As shown in Figure 1B, LFH5 and LFH10
177
showed more peptides as compared to other hydrolysates. The peptide with the lowest
178
molecular mass in these hydrolysates was about 5 kD, while molecular masses of
179
peptides in LFH5 and LFH10 ranged from 10 to 17 kD.
180
Effects of Peptides on Proliferation of Osteoblast
181
MC3T3-E1 cells were cultured for 24, 48, and 72 h in presence of 100 µg/mL LFH
182
lyophilized powder. Many studies have reported that 100 µg/mL of lactoferrin exhibited
183
better osteogenic activity,37,38 which was consistent with the results of the present study.
184
Therefore, we investigated the activity of 100 µg/mL lactoferrin. Lactoferrin, LFH5, and
185
LFH10 increased the survival of MC3T3-E1 cells, as demonstrated by the MTT assay
186
(Figure 2). This result suggests that lactoferrin promoted the proliferation of primary
187
osteoblast and osteoblastic cell lines.37,39 However, the activity of LFH5 was
188
significantly higher than that of lactoferrin at 24 h, indicating that lactoferrin took
189
longer time to stimulate osteoblast proliferation via receptor and signaling pathways40,15
190
and that hydrolysates with small peptides may stimulate osteoblast proliferation at a
191
shorter time. LFH5 showed highest activity at 48 and 72 h, although the difference
192
between LFH5 and lactoferrin activities was not significant. 10
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In comparison with the control group, LFH5 significantly stimulated proliferation
194
of osteoblast cells after 24, 48, and 72 h of treatment, while LFH10 significantly
195
stimulated osteoblast cell proliferation after 24 and 48 h of treatment (Figure 2). An
196
increase of 15.29%, 29.73%, and 41.61% in cell growth was observed after 24, 48, and
197
72 h of LFH5 treatment, respectively. Although the proliferation ratio of
198
LFH30-LFH240 hydrolysates at 24 h and LFH120-LFH240 hydrolysates at 72 h seem
199
to be decreased, these hydrolysates showed no significant difference as compared with
200
the control group. Natural and synthetic peptides derived from different sources have
201
shown stimulatory effect on cell proliferation at 24-72 h.41,42 Therefore, LFH5 was
202
enriched with promising bioactive peptides and can be subjected to purification because
203
of its multiple constituents.
204
Isolation of Peptides with Stimulatory Effect on Proliferation of
205
Osteoblast
206
As shown in Figure 3A, we chose five fractions P1-P5 eluted from SP Sepharose
207
Fast Flow column and investigated their effect on osteoblast proliferation at 100 µg/mL
208
using MTT assay. As shown in Figure 4, P1, P4, and P5 significantly stimulated
209
proliferation of cells. Of the five fractions, P5 showed the highest activity after 24, 48,
210
and 72 h of treatment. An increase of 31.78%, 29.76%, and 33.73% in cell growth was
211
observed after 24, 48, and 72 h, respectively.
212
P5 fraction from several runs were pooled, concentrated by ultrafiltration, and used
213
for the subsequent gel-filtration chromatography. As shown in Figure 3B, two peptide
214
fractions P5-a and P5-b were isolated and their stimulatory effect on osteoblast 11
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proliferation analyzed at 100 µg/mL using MTT assay. As shown in Figure 5, after
216
24~72 h of treatment, stimulatory effect of P5-a on osteoblast proliferation was higher
217
than that of P5-b and P5. An increase of 23.42 %, 13.24%, and 10.59% in cell growth
218
was observed after P5-a treatment for 24, 48, and 72 h, respectively. The purity and
219
molecular mass of P5-a was analyzed by electrophoresis. Tricine-SDS-PAGE analysis
220
showed that P5-a comprised two different peptides with molecular masses of 9.35 and
221
6.95 kD (Figure 6).
222
Identification of Peptides by HPLC-ESI–MS/MS
223
As shown in Table 1, amino acid sequences of peptides from P5-a were identified
224
by HPLC-ESI–MS/MS. Six peptides were identified based on the ESI-MS/MS and
225
Mascot analysis, combining with the selection standard of scores more than 40. These
226
peptides derived from different fractions of lactoferrin displayed sequence as follows:
227
WCTISQPEWFK (fraction 27-37aa), LGAPSITCVR (fraction 48-57aa), AFALECIR
228
(fraction 59-66aa), GEGENQCACSSR (fraction 194-205aa), CLQDGAGDVAFVKE
229
(fraction 217-229aa), and ECHLAQVPSHAVVAR (fraction 263-277aa).
230
As P5-a was isolated from pepsin hydrolysate of lactoferrin using chromatography,
231
the theoretical pepsin cleavage sites in lactoferrin molecule were determined by
232
bioinformatics based on the BIOPEP database.43 At pH 1.3 and > 2.0, lactoferrin
233
molecule displayed 102 and 274 pepsin cleavage sites, respectively (Figure 7). The
234
composition and size of peptides produced may vary with conditions such as enzyme
235
concentration, hydrolysis period, pH, and temperature. As P5-a comprised peptides
236
isolated from LFH5, it may include peptides with relatively longer amino acid chains. 12
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BIOPEP analysis suggested that WCTISQPEWFK (fraction 27-37aa), LGAPSITCVR
238
(fraction 48-57aa), and AFALECIR (fraction 59-66aa) are derived from Peptide 1 with
239
calculated Mr. = 6976.36 Da (fraction 20-78), while GEGENQCACSSR (fraction
240
194-205aa), CLQDGAGDVAFVKE (fraction 217-229aa), and ECHLAQVPSHAVVAR
241
(fraction 263-277aa) are derived from Peptide 2 with calculated Mr. = 9544.71 Da
242
(fraction 191-277). These two peptides were observed as two bands corresponding to
243
6.95 and 9.53 kD on the SDS-PAGE gel (Figure 6). Thus, P5-a comprised two peptides,
244
APRKNVRWCTISQPEWFKCRRWQWRMKKLGAPSITCVRRAFALECIRAIAEKK
245
ADAVTL (Peptide 1) and LCKGEGENQCACSSREPYFGYSGAFKCLQDGAGDVAF
246
VKETTVFENLPEKADRDQYELLCLNNSRAPVDAFKECHLAQVPSHAVVAR
247
(Peptide 2). The identified peptide profile is shown in Figure 7. Sequences in blue
248
letters indicate these six peptides identified by HPLC-ESI–MS/MS (Table 1), while
249
those highlighted in yellow and green indicate Peptide 1 and 2, respectively.
250
In the present study, lactoferrin was hydrolyzed by pepsin to obtain fractions with
251
stimulatory effect on cell proliferation. The active fraction P5-a from lactoferrin
252
hydrolysate
253
cation-exchange chromatography and Superdex Peptide 10/300 GL gel chromatography.
254
P5-a was shown to significantly stimulate proliferation of osteoblastic cell line
255
MC3T3-E1 at 100 µg/mL concentration and comprised two long peptide components:
256
APRKNVRWCTISQPEWFKCRRWQWRMKKLGAPSITCVRRAFALECIRAIAEKK
257
ADAVTL (fraction 20-78) and LCKGEGENQCACSSREPYFGYSGAFKCLQDGAGD
258
VAFVKETTVFENLPEKADRDQYELLCLNNSRAPVDAFKECHLAQVPSHAVVAR
was subjected to purification using SP Sepharose Fast Flow
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(fraction 191-277).
260 261
ACKNOWLEDGEMENTS
262
We would like to thank Applied Protein Technology in Shanghai for determining the
263
sequence of peptides.
264
FUNDING SOURCES
265
This study was financially supported by the National Natural Science Foundation of
266
China
267
(2013BAD18B06-03).
(31371805),
the
National
Science
&
Technology
268 269
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399
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FIGURE CAPTIONS
401
Figure 1. Protein profiles of lactoferrin peptides. (A) SDS-PAGE. 1: Marker; 2:
402
Lactoferrin; 3: LFH5; 4: LFH10; 5: LFH30; 6: LFH60; 7: LFH90; 8: LFH120; 9:
403
LFH180; and 10: LFH240. (B) Tricine-SDS-PAGE. 1: Marker; 2: LFH5; 3: LFH10; 4:
404
LFH30; 5: LFH60; 6: LFH90; 7: LFH120; 8: LFH180; and 9: LFH240.
405
Figure 2. Effects of lactoferrin peptides on the proliferation of osteoblast. Error bars
406
indicate standard deviation. *p < 0.05 versus control; #p < 0.05 versus LFH5.
407
Figure 3. Purification of LFH5 by column chromatography. (A) Elution diagram of SP
408
Sepharose Fast Flow column. (B) Elution diagram of Superdex Peptide 10/300 GL
409
column.
410
Figure 4. Effects of peaks collected by cation-exchange chromatography on the
411
proliferation of osteoblast. Error bars indicate standard deviation. *p < 0.05 versus
412
control; &p < 0.05 versus P5.
413
Figure 5. Effects of fractions collected by gel-filtration chromatography on the
414
proliferation of osteoblast. Error bars indicate standard deviation. *p < 0.05 versus
415
control; $p < 0.05 versus P5-a.
416
Figure 6. Tricine-SDS-PAGE of P5-a. Analysis was carried out using 4% stacking and
417
16% separating gels. Low-range protein marker was a mixture of six recombinant
418
proteins and synthetic peptides (1.7 to 42 kD).
419
Figure 7. Peptides distribution in the partial amino acid sequence of lactoferrin (1-360).
420
The six peptides indicated in blue letters were identified by HPLC-ESI–MS/MS. The
421
peptides highlighted in yellow and green are Peptide 1 and Peptide 2, respectively. The 21
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vertical lines indicate pepsin cleavage sites in lactoferrin.
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TABLES Table 1. Identification of Peptides from Hydrolysate of P5-a by Trypsin. Position in No.
Peptide mass
Sequence lactoferrin
(Da)
pI
Hydrophilicity
Scores
1
WCTISQPEWFK
27-37
1481.69
6.4
-0.5
43.64
2
LGAPSITCVR
48-57
1073.58
9.0
-0.3
57.82
3
AFALECIR
59-66
979.50
6.2
-0.2
54.63
4
GEGENQCACSSR
194-205
1354.51
4.3
0.6
42.77
5
CLQDGAGDVAFVK
217-229
1379.662
3.9
0.0
80.71
6
ECHLAQVPSHAVVAR
263-277
1673.85
7.4
-0.2
72.92
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24h
*
1.2 #
#
#
#
1.0
b
#
#
#
#
#
0.8
0.6 ol ntr Co
LF FH5 H10 H30 H60 H90 120 180 240 L LF LF LF LF LFH LFH LFH
(A)
48h
1.4
Ratio of proliferation
Ratio of proliferation
1.4
* *
1.2
*
*
#
* #
#
*
*
1.0 0.8 0.6 ol LF FH5 H10 H30 H60 H90 120 180 240 ntr o L L F L F L F L F FH FH FH C L L L
(B)
25
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Ratio of proliferation
1.5
*
*
72h
*
1.2
#
#
#
# #
#
#
0.9
0.6 nt Co
rol LF FH5 H10 H30 H60 H90 120 180 240 L L F L F L F L F L FH L FH L FH
(C)
Figure 2
26
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Absorbance at 280 nm Electrical conductivity
P0
2000
100 80
1600
60
1200 P1
800
40 P4 P5
400
20
P2 P3
0
0 0
100
200
300
400
500
600
700
Elution volume (mL)
Absorbance at 280 nm (mAU)
(A)
P5-b
1080
P5-a
810 540 270 0 0
5
10
15
20
25
30
Elution volume (mL) (B)
Figure 3
27
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40
Electrical conductivity (mS/cm)
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Absorbance at 280 nm (mAU)
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24h
Ratio of proliferation
1.4
* *&
1.2 &
&
Control
P0
*&
&
1.0
&
0.8 0.6 P1
P2
P3
P4
P5
(A)
48h
1.4
Ratio of proliferation
* *&
1.2 *&
*&
&
&
&
1.0 0.8 0.6 Control
P0
P1
P2
P3
P4
(B)
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72h
1.4
*
Ratio of proliferation
*&
*&
*&
1.2
&
&
&
1.0 0.8 0.6 Control
P0
P1
P2
P3
P4
(C)
Figure 4
29
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P5
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24h
Ratio of proliferation
1.4 *
1.2 $ $
1.0
$
0.8 0.6 Control
P5
P5-a
P5-b
(A)
48h
Ratio of proliferation
1.4
1.2
* $
$
1.0
0.8
0.6 Control
P5
P5-a
P5-b
(B)
30
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72h
Ratio of proliferation
1.4 1.2 $
1.0
*$
0.8 0.6 Control
P5
P5-a
P5-b
(C)
Figure 5
31
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Figure 6
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Figure 7
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Graphic for Table of Contents
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