CN109160944B

CN109160944B - Bioactive polypeptide ATAVPIIFF, and preparation method and application thereof

Info

Publication number: CN109160944B
Application number: CN201811002919.9A
Authority: CN
Inventors: 张少辉; 占文静; 汪超; 李阜烁; 范梦珠; 张伯宇; 亚辛·黑马尔
Original assignee: Zhejiang Huitai Life Health Technology Co ltd; Shanghai Jiaotong University
Current assignee: Zhejiang Huitai Life Health Technology Co ltd; Shanghai Jiaotong University
Priority date: 2018-08-30
Filing date: 2018-08-30
Publication date: 2021-03-23
Anticipated expiration: 2038-08-30
Also published as: CN109160944A

Abstract

The invention relates to the field of proteins, in particular to a bioactive polypeptide ATAVPIIFF, a preparation method and application thereof, wherein the amino acid sequence of the bioactive polypeptide ATAVPIIFF is Ala-Thr-Ala-Val-Pro-Ile-Ile-Phe-Phe. Through in vitro immune function regulation experiments and in vivo anti-aging experiments, the polypeptide ATAVPIIFF is verified to have better immune function regulation and anti-aging activity, on one hand, the bioactive polypeptide ATAVPIIFF disclosed by the invention can enhance the in vitro proliferation capacity of lymphocytes and macrophages, improve the resistance of an organism to external pathogen infection and reduce the morbidity of the organism; on the other hand, the activity of an anti-peroxidase system in vivo can be improved, and the function of resisting exogenous stimulation of an organism is enhanced, so that the probability of aging, aging and illness of the organism is reduced, and the method has very important significance for developing foods, health-care products and medicines with immunoregulation function and anti-aging function.

Description

Bioactive polypeptide ATAVPIIFF, and preparation method and application thereof

Technical Field

The invention relates to the field of proteins, in particular to a bioactive polypeptide ATAVPIIFF, and a preparation method and application thereof.

Background

In the process of fermenting the cow milk by the lactic acid bacteria, a part of protein in the cow milk is metabolized and utilized by the lactic acid bacteria, and a series of physiological and biochemical reactions occur, so that the protein is changed into polypeptide or free amino acid which is digested and absorbed by a human body or directly enters the blood circulation of the human body through the absorption and transportation of small intestinal epithelial cells. The lactobacillus also has some self-synthesized protein polypeptide fragments for the bacteria to grow. Among these polypeptides, some have a specific physiological function and are called "bioactive peptides".

It is particularly important to find safe bioactive peptides in natural food sources. In recent years, some food-derived polypeptides, such as short peptides of corn, soybean peptides, milk polypeptides, etc., have been found to have good biological activity. The polypeptides can be obtained through various ways such as microbial fermentation, digestion and enzymolysis and the like, and most of the polypeptides with biological activity consist of 2-20 amino acid residues, have the molecular weight of less than 6000Da and contain a certain amount of hydrophobic amino acids and aromatic amino acids.

Immunoactive peptides are a class of bioactive polypeptides that are first obtained from milk following opioid peptide discovery and demonstrate their physiological activity. Jolles et al found in 1981 for the first time that a hexapeptide with an amino acid sequence Val-Glu-Pro-Ile-Pro-Tyr can be obtained by hydrolyzing human milk protein with trypsin, and in vitro experiments prove that the hexapeptide can enhance the phagocytosis of mouse abdominal cavity macrophages to sheep erythrocytes. Migliore-Samour et al found that the casein-derived hexapeptide Thr-Thr-Met-Pro-Leu-Trp was able to stimulate phagocytosis of murine peritoneal macrophages by sheep red blood cells and to enhance resistance to Klebsiella pneumoniae. Lemna hexandra et al, fed rats with synthetic milk-derived immunoregulatory peptide (PGPIPN), found that phagocytosis of macrophages in the abdominal cavity of rats and immunoregulatory function related to erythrocytes were significantly enhanced.

Researches show that the immune active peptide can not only enhance the immunity of the organism, stimulate the proliferation of lymphocytes of the organism, enhance the phagocytic function of macrophages, promote the release of cell factors, improve the capability of the organism for resisting the infection of external pathogens, reduce the morbidity of the organism, but also can not cause the immune rejection reaction of the organism.

Aging is a natural phenomenon, and the process is often accompanied by changes of antioxidant level, organ tissues and immune factors, wherein cytokines are subjected to complex changes, such as proinflammatory cytokines IL-6, IL-4, TNF-alpha and the like show a growing trend, and IL-6 and TNF-a are considered to play an important role in the process of the senile diseases. With the development of genetics and molecular biology, research on the biological aging mechanism has made favorable progress. Researchers have found that some genes can significantly increase the life span of some model organisms by as much as 6-fold by using single gene mutation experiments in these organisms, such as mice, Drosophila, and caenorhabditis elegans.

The anti-aging peptide has the advantages that the anti-aging peptide is a novel anti-aging agent, has incomparable advantages with amino acid in the aspect of physiological function, can promote or inhibit enzymes in organisms, improve the absorption and utilization of minerals and other nutrient elements, clear away free radicals in the bodies, enhance the self anti-oxidation capability of the organisms and delay aging. Therefore, the nutrition and health care effects of bioactive peptides have become the focus of research on the subjects of scholars at home and abroad. Experiments and researches by meaningful people find that the milk-derived bioactive small peptide can effectively prolong the life of the drosophila and delay the aging of the drosophila, and has better antioxidation effect, and presumably is rich in thiopeptides. The results of Zhou Zhi Hui et al show that the bovine colostrum extract can obviously improve the SOD activity in serum of the elderly, reduce lipid peroxides of the SOD, enhance the oxidation resistance of organisms and have certain anti-aging function.

At present, there are many researches on bioactive polypeptides, for example, chinese patent CN105254738A discloses a milk-derived bioactive polypeptide DELQDKIH derived from β -casein, chinese patent CN105254739A discloses a milk-derived bioactive polypeptide GTQYTD derived from α s 1-casein, and chinese patent CN105254740A discloses a milk-derived bioactive polypeptide NQFYQKF derived from α s 2-casein.

Disclosure of Invention

The invention aims to provide a bioactive polypeptide ATAVPIIFF, and a preparation method and application thereof.

The purpose of the invention can be realized by the following technical scheme:

in a first aspect of the invention, there is provided a biologically active polypeptide ATAVPIIFF having an amino acid sequence of Ala-Thr-Ala-Val-Pro-Ile-Ile-Phe-Phe, as set forth in SEQ ID NO: 1 is shown.

Preferably, the bioactive polypeptide is derived from lactobacillus helveticus mycoprotein. In particular, the protein is derived from LBH _0027| m.24LBH _0027| g.24ORF LBH _0027| g.24LBH _0027| m.24type:5prime _ partial len:320(+) LBH _0027:1-960(+) protein, and is the amino acid residue at the 17 th to 25 th positions of the protein. LBH-0027. mu.m.24LBH-0027. mu.g.24ORF LBH-0027. mu.g.24LBH-0027. mu.m.24type: 5prime partial len:320(+) LBH-0027: 1-960(+) protein amino acid sequence is as shown in SEQ ID NO: 3, respectively.

The amino acid sequence of LBH-0027 | m.24LBH-0027 | g.24ORF LBH-0027 | g.24LBH-0027 | m.24type:5prime partial len:320(+) LBH-0027: 1-960(+) protein and the corresponding nucleotide sequence are known techniques, and a nucleotide fragment encoding amino acid residues 17 to 25 of the protein encodes a mature biologically active polypeptide ATAVPIIFF.

Preferably, the bioactive polypeptide has an immunoregulatory function and an anti-aging function.

In a second aspect of the present invention, there is provided a nucleotide fragment encoding the biologically active polypeptide ATAVPIIFF, the sequence of which is: 5'-cta ctg ctg ttc cta tta tat ttt ttg-3', as shown in SEQ ID NO: 2, respectively.

In the third aspect of the invention, the preparation method of the bioactive polypeptide ATAVPIIFF is provided, which can be artificially synthesized by a genetic engineering method, can be directly obtained from lactobacillus helveticus thallus by a cell disruption separation and purification method, and can be directly prepared by chemical synthesis.

In the fourth aspect of the invention, the application of the bioactive polypeptide ATAVPIIFF in preparing food, health products, medicines or cosmetics with immunoregulation function is provided.

In the fifth aspect of the invention, the application of the bioactive polypeptide ATAVPIIFF in preparing food, health-care products or medicines with the anti-aging function is provided.

In a sixth aspect, the invention provides an application of the bioactive polypeptide ATAVPIIFF in preparing food, health care products or medicines with immune regulation function and anti-aging function.

Specifically, the bioactive polypeptide ATAVPIIFF of the present invention can be used for preparing cosmetics for reducing free radical damage to skin, medicines for regulating immunity and/or resisting aging; and because the product of the bioactive polypeptide ATAVPIIFF degraded by gastrointestinal tract still has bioactivity, the bioactive polypeptide ATAVPIIFF can be used for preparing foods such as yoghourt and the like, health-care products for regulating immunity and oral medicines for regulating immunity and/or resisting aging.

In a seventh aspect of the invention, there is provided an immunomodulatory product comprising said biologically active polypeptide ATAVPIIFF or a derivative of said biologically active polypeptide ATAVPIIFF; the immunoregulation product comprises immunoregulation food, immunoregulation health-care products, immunoregulation medicaments or immunoregulation cosmetics; the derivative of the biologically active polypeptide ATAVPIIFF refers to a polypeptide derivative obtained by performing modifications such as hydroxylation, carboxylation, carbonylation, methylation, acetylation, phosphorylation, esterification or glycosylation on an amino acid side chain group, an amino terminal or a carboxyl terminal of the biologically active polypeptide ATAVPIIFF.

In an eighth aspect of the invention, there is provided an anti-aging product comprising the biologically active polypeptide ATAVPIIFF or a derivative of the biologically active polypeptide ATAVPIIFF; the anti-aging product comprises anti-aging food, anti-aging health care product or anti-aging drug; the derivative of the biologically active polypeptide ATAVPIIFF refers to a polypeptide derivative obtained by performing modifications such as hydroxylation, carboxylation, carbonylation, methylation, acetylation, phosphorylation, esterification or glycosylation on an amino acid side chain group, an amino terminal or a carboxyl terminal of the biologically active polypeptide ATAVPIIFF.

In the ninth aspect of the present invention, a product having both immunoregulatory function and anti-aging function is provided, which comprises the bioactive polypeptide ATAVPIIFF or a derivative of the bioactive polypeptide ATAVPIIFF; products with immunoregulatory and anti-aging functions include foods, health products or drugs; the derivative of the biologically active polypeptide ATAVPIIFF refers to a polypeptide derivative obtained by performing modifications such as hydroxylation, carboxylation, carbonylation, methylation, acetylation, phosphorylation, esterification or glycosylation on an amino acid side chain group, an amino terminal or a carboxyl terminal of the biologically active polypeptide ATAVPIIFF.

The bioactive polypeptide ATAVPIIFF has the following beneficial effects: the bioactive polypeptide ATAVPIIFF has good activity of regulating the immunity of the organism and anti-aging activity; on one hand, the bioactive polypeptide ATAVPIIFF can enhance the in vitro proliferation capacity of lymphocytes and macrophages, improve the capability of an organism for resisting infection of external pathogens and reduce the morbidity of the organism; on the other hand, the activity of an anti-peroxidase system in vivo can be improved, and the function of resisting exogenous stimulation of an organism is enhanced, so that the probability of aging, aging and illness of the organism is reduced, and the method has very important significance for developing dairy products and health care products with immunoregulation function and anti-aging function.

Drawings

FIG. 1: mass chromatogram extraction (m/z 978.5601);

FIG. 2: a secondary mass spectrum of a fragment with a mass to charge ratio of 978.5601;

FIG. 3: fragmentation of polypeptide az and by with mass-to-charge ratio of 978.5601;

FIG. 4: spleen change of each group of experimental animal mice;

(a) spleen tissue maps of mice in the low-dose gavage group; (b) spleen tissue maps of mice in the high-dose gavage group;

(c) spleen tissues of blank mice; (d) is a spleen tissue map of mice in an animal model group;

FIG. 5: serum IL-6 profiles for each group of mice;

FIG. 6: serum TNF-alpha profiles for each group of mice;

FIG. 7: serum IL-2 profiles for each group of mice;

FIG. 8: serum IL-10 profiles for each group of mice.

Detailed Description

Before the present embodiments are further described, it is to be understood that the scope of the invention is not limited to the particular embodiments described below; it is also to be understood that the terminology used in the examples is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention.

When numerical ranges are given in the examples, it is understood that both endpoints of each of the numerical ranges and any value therebetween can be selected unless the invention otherwise indicated. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In addition to the specific methods, devices, and materials used in the examples, any methods, devices, and materials similar or equivalent to those described in the examples may be used in the practice of the invention in addition to the specific methods, devices, and materials used in the examples, in keeping with the knowledge of one skilled in the art and with the description of the invention.

Unless otherwise indicated, the experimental methods, detection methods, and preparation methods disclosed herein all employ techniques conventional in the art of molecular biology, biochemistry, chromatin structure and analysis, analytical chemistry, cell culture, recombinant DNA technology, and related arts. These techniques are well described in the literature, and may be found in particular in the study of the MOLECULAR CLONING, Sambrook et al: a LABORATORY MANUAL, Second edition, Cold Spring Harbor LABORATORY Press, 1989 and Third edition, 2001; ausubel et al, Current PROTOCOLS IN MOLECULAR BIOLOGY, John Wiley & Sons, New York, 1987 and periodic updates; the series METHODS IN ENZYMOLOGY, Academic Press, San Diego; wolffe, CHROMATIN STRUCTURE AND FUNCTION, Third edition, Academic Press, San Diego, 1998; (iii) METHODS IN ENZYMOLOGY, Vol.304, Chromatin (P.M.Wassarman and A.P.Wolffe, eds.), Academic Press, San Diego, 1999; and METHODS IN MOLECULAR BIOLOGY, Vol.119, chromatography Protocols (P.B.Becker, ed.) Humana Press, Totowa, 1999, etc.

The invention is described in detail below with reference to the figures and specific embodiments.

Example 1 Artificial Synthesis of active peptide ATAVPIIFF

Synthesis of bioactive peptide

1.3 g of RINK resin (degree of substitution 0.3mmol/g) was weighed into a 150ml reactor and soaked with 50ml of Dichloromethane (DCM).

After 2.2 hours, the resin was washed with 3 resin volumes of N-Dimethylformamide (DMF) and then drained, and this was repeated four times and the resin was drained until use.

3. The Fmoc protecting group on the resin was removed by adding a quantity of 20% piperidine (piperidine/DMF: 1:4, v: v) to the reactor and shaking on a decolourising shaker for 20 min. After deprotection, the resin was washed four times with 3 resin volumes of DMF and then drained.

4. And (3) detecting a small amount of resin by a ninhydrin (ninhydrin) method (detecting A and B, respectively, and reacting at 100 ℃ for 1min), wherein the resin is colored, which indicates that the deprotection is successful.

5. Weighing a proper amount of amino acid Ala and a proper amount of 1-hydroxy-benzotriazole (HOBT) into a 50ml centrifuge tube, adding 20ml of DMF to dissolve the amino acid Ala and the 1-hydroxy-benzotriazole (HOBT), then adding 3ml of N, N diisopropyl carbodiimide (DIC) to shake and shake for 1min, adding the solution into a reactor after the solution is clarified, and then placing the reactor into a 30 ℃ shaking table to react.

After 6.2 hours, the column was capped with a suitable amount of acetic anhydride (acetic anhydride: DIEA: DCM ═ 1:1:2, v: v: v) for half an hour, then washed four times with 3 resin volumes of DMF and drained until needed.

7. The Fmoc protecting group on the resin was removed by adding a quantity of 20% piperidine (piperidine/DMF: 1:4, v: v) to the reactor and shaking on a decolourising shaker for 20 min. After deprotection was washed four times with DMF and then drained.

8. And (3) detecting a small amount of resin by a ninhydrin (ninhydrin) method (detecting A and B, respectively, and reacting at 100 ℃ for 1min), wherein the resin is colored, which indicates that the deprotection is successful.

9. Weighing a second proper amount of amino acid and a proper amount of HOBT in a 50ml centrifuge tube, adding 25ml of DMF to dissolve the amino acid and the HOBT, adding 2.5ml of DIC to shake and shake for 1min, adding the solution into a reactor after the solution is clarified, and then placing the reactor in a shaking table at 30 ℃ to react.

After 10.1 hours, a small amount of resin is taken for detection, and the detection is carried out by an indanthrone method (two drops are respectively detected A and B, and the reaction is carried out for 1min at 100 ℃), if the resin is colorless, the reaction is complete; if the resin is colored, the condensation is not complete and the reaction is continued.

11. After the reaction was completed, the resin was washed four times with DMF and then drained, and a certain amount of 20% piperidine (piperidine/DMF ═ 1:4, v: v) was added to the reactor, and the mixture was shaken on a decolorizing shaker for 20min to remove the Fmoc-protecting group from the resin. After the protection is removed, washing with DMF for four times, and then draining to detect whether the protection is removed.

12. The amino acids Thr, Ala, Val, Pro, Ile, Phe and Phe are ligated in sequence according to steps 9-11.

13. After the last amino acid had been grafted, the protection was removed, washed four times with DMF and the resin was drained with methanol. The polypeptide was then cleaved from the resin with 95 cleavage medium (trifluoroacetic acid: 1,2 ethanedithiol: 3, isopropylsilane: water: 95:2:2:1, v: v: v) (10 ml of cleavage medium per gram of resin) and centrifuged four times with glacial ethyl ether (cleavage medium: ethyl ether: 1:9, v: v).

To this end, bioactive peptide ATAVPIIFF was synthesized.

Confirmation of biologically active peptides

1) UPLC analysis

UPLC conditions were as follows:

the instrument comprises the following steps: waters ACQUITY UPLC ultra-high performance liquid-electrospray-quadrupole-time-of-flight mass spectrometer

Specification of chromatographic column: BEH C18 chromatographic column

Flow rate: 0.4mL/min

Temperature: 50 deg.C

Ultraviolet detection wavelength: 210nm

Sample introduction amount: 2 μ L

Gradient conditions: solution A: water containing 0.1% formic acid (v/v), liquid B: acetonitrile containing 0.1% formic acid (v/v)

2) Mass spectrometric analysis

The mass spectrometry conditions were as follows:

ion mode: ES +

Mass range (m/z): 100-1000

Capillary voltage (Capillary) (kV): 3.0

Sampling cone (V): 35.0

Ion source temperature (. degree. C.): 115

Desolvation temperature (. degree. C.): 350

Desolventizing gas stream (L/hr): 700.0

Collision energy (eV): 4.0

Scan time (sec): 0.25

Inner scan time (sec): 0.02

According to the analysis method, the ultra-high performance liquid chromatography-electrospray-quadrupole-time-of-flight mass spectrometry is used for carrying out chromatographic analysis and mass spectrometric analysis on the bioactive peptide ATAVPIIFF, the mass chromatogram extraction diagram is shown in figure 1, the secondary mass spectrogram of the peak and the az and by fracture conditions are shown in figures 2 and 3, the polypeptide mass-to-charge ratio of the peak is 978.5601Da, and the retention time is 47.6 min.

3) Results

As can be seen from FIG. 3, according to the cases of az and by fragmentation, the fragment sequence with mass-to-charge ratio of 978.5601Da obtained by analysis and calculation of Mascot software is Ala-Thr-Ala-Val-Pro-Ile-Ile-Phe (ATAVPIIFF) and is marked as SEQ ID NO: 1. the fragment corresponds to the 17-25 residue sequence of LBH-0027. mu.m.24 LBH-0027. mu.g.24 ORF LBH-0027. mu.g.24LBH-0027. mu.m.24 type 5prime partial len:320(+) LBH-0027: 1-960(+) protein, see SEQ ID NO: 3.

example 2 experiment of the Activity of bioactive peptides in regulating the Immunity of the organism

First, MTT method for testing in vitro lymphocyte proliferation capacity experiment of bioactive polypeptide ATAVPIIFF

1. Experimental materials and instruments:

reagents and materials: experimental animals balb/c mice (male 6-8 weeks old, animal experiment center of Shanghai university of transportation, college of agriculture and biology); the biologically active polypeptide ATAVPIIFF obtained in example 1; mouse lymphocyte extract (ex solibao); RPMI1640 medium (purchased from GIBCO); 3- (4, 5-Dimethylthiazol-2) -2, 5-diphenyltetrazolium bromide salt (MTT, available from Amresco, Inc.); concanavalin (ConA, available from Sigma); bovine serum albumin (BSA, available from Genebase); pepsin (available from Sigma); pancreatin (Corolase PP, from AB).

The instrument equipment comprises: LRH-250F Biochemical incubator, Shanghai Hengshi Co., Ltd; GL-22M high speed refrigerated centrifuge, shanghai luxiang instrument centrifuge instruments ltd; hera cell 150 CO2 incubator, Heraeus; dragon Wellscan MK3 microplate reader, Labsystems Inc.; ALPHA 1-2-LD vacuum freeze drier, Christ company; ultra performance liquid chromatography-quadrupole time-of-flight mass spectrometer, waters corporation.

2. The experimental method comprises the following steps:

taking mouse spleen under aseptic condition, extracting mouse lymphocyte with lymphocyte extract, and performing primary culture. The cell density was adjusted to 2.5X 10 with complete RPMI1640 medium⁶one/mL. To a 96-well cell culture plate were added in sequence: 100 μ L mouse lymphocyte suspension, 100 μ L RPMI1640 complete medium, 20 μ L concanavalin, 100 μ L sample. In addition, a blank control group (PBS with pH7.2-7.4 and 3 mol/L) and a negative control group (500 mu g/mL BSA) are arranged, and the research shows that the blank control group has no influence on the in vitro lymphocyte proliferation. Each set of 3 replicates. At 5% CO₂Culturing at 37 deg.C for 68h, adding 20 μ L MTT into each well under aseptic condition, culturing for 4h, carefully removing supernatant, adding 100 μ L dimethyl sulfoxide into each well, incubating at 37 deg.C for 10min, shaking, and measuring absorbance at 570nm with microplate reader.

The in vitro lymphocyte proliferation capacity is expressed by a stimulation index and is calculated as follows:

in the formula: a. the₁Absorbance at 570nm for the blank; a. the₂Absorbance at 570nm for the negative control, A₃The absorbance at 570nm for the experimental group.

3. Experimental results and analysis:

TABLE 1 Effect of biologically active polypeptide ATAVPIIFF on in vitro lymphocyte proliferation

Experiment grouping	Stimulation index SI
		Negative control group	1
ATAVPIIFF	1.175±0.021*

Note: the number marked as significant difference (P <0.05) compared to the negative control.

The results are shown in Table 1. As can be seen from Table 1, under the condition that the mass concentration of the bioactive peptide ATAVPIIFF is 100 μ g/mL, the stimulation index of the bioactive peptide ATAVPIIFF is greater than that of BSA, which indicates that ATAVPIIFF can stimulate the proliferation of mouse lymphocytes in vitro to some extent. And ATAVPIIFF reached a stimulation index of 1.175, which was significantly different from that of the negative control group (P < 0.05). Therefore, the active polypeptide ATAVPIIFF can be considered to have the capacity of remarkably promoting the mouse lymphocyte proliferation, can be eaten as a health product or an additive, and can improve the immunity of animals and human bodies.

Second, MTT method for measuring in vitro macrophage proliferation ability experiment of bioactive polypeptide ATAVPIIFF

1) Experimental reagent and instrument

Reagent: experimental animals balb/c mice (male 6-8 weeks old) were collected at the animal Experimental center of the college of agriculture and biology of Shanghai university of transportation; the biologically active polypeptide ATAVPIIFF obtained in example 1; 3- (4, 5-Dimethylthiazol-2) -2, 5-diphenyltetrazolium bromide (MTT) Amresco; LPS (lipopolysaccharide) Sigma company; bovine Serum Albumin (BSA) Genebase; triple solutions, aqueous solutions containing 10% SDS, 5% isobutanol and 0.012mol/L HCl.

The instrument equipment comprises: LRH-250F Biochemical incubator Shanghai Hengshi Co., Ltd; GL-22M high speed refrigerated centrifuge Shanghai Luxiang apparatus centrifuge Instrument Co., Ltd; hera cell 150 CO₂Incubator Heraeus; dragon Wellscan MK3 microplate reader Labsystems.

2) The test method comprises the following steps:

balb/c mice were injected intraperitoneally with 2ml of 2% (w/w) sterile starch solution for three consecutive days, and sacrificed by cervical dislocation 24 hours after the last injection. Peeling off the abdominal skin, sucking 4 ℃ Phosphate Buffer Solution (PBS) by using a syringe to repeatedly wash the abdominal cavity, centrifuging the washed solution by using a centrifuge tube for 10 minutes after collecting the washed solution, discarding the supernatant after centrifuging the washed solution (1000rpm and 4 ℃), washing the washed solution twice by using 4 ℃ RPMI1640 complete culture solution (containing 10% FBS), staining the washed solution by using 0.2% trypan blue solution to detect the vitality of the cells, and confirming that the collected viable macrophages account for more than 95%. After reading the cell counting plate, the cell concentration was adjusted to the appropriate concentration.

The cell suspension that had been blown to complete suspension was added to a 96-well cell culture plate at 37 ℃ with 5% CO in an appropriate volume₂After culturing for 4 hours under the environment, removing liquid in the holes, carefully cleaning the bottom of the holes of the cell culture plate by using a complete culture solution RPMI1640 at 37 ℃, and washing the cells and cell fragments which are not attached to the walls to obtain the purified attached abdominal cavity macrophages. 0.2ml of RPMI1640 complete medium was added to each well, and the small peptide sample for experiment and LPS were dissolved in the medium in advance and then added to start cell culture.

After obtaining the purified adherent abdominal cavity macrophages, 200 mul/hole of RPMI1640 complete culture solution (10% FBS) dissolved with bioactive polypeptide ATAVPIIFF (1mg/ml) is added into each hole of the experimental group for continuous culture for 48 h; negative control group added BSA (500. mu.g/mL) dissolved in RPMI1640 complete medium (10% FBS) 200. mu.l/well; the blank group was continuously cultured for 48 hours with the addition of 200. mu.l/well of RPMI1640 complete medium (10% FBS). In addition, the experimental group, the negative control group and the blank group are respectively provided with a normal group and an inflammation group; LPS is added into the inflammation group when the inflammation group is cultured for 24 hours until the final concentration is 100 ng/ml; LPS is not added in a normal group; and the normal group and the inflammatory group were added with 5% MTT 20. mu.l/well at 44 h; after the cell culture reached 48h, 100. mu.l/well of the triple lysis buffer was added to terminate the culture, and after overnight lysis, the absorbance value (OD570) of each well was measured by a microplate reader at a wavelength of 570nm, and the Growth index (Growth Indices) was calculated as follows:

wherein the blank culture solution is RPMI1640 complete culture solution containing 10% FBS.

3) Results and analysis of the experiments

TABLE 2 Effect of biologically active polypeptide ATAVPIIFF on macrophage proliferation in vitro

Experiment grouping	Normal group GI	GI inflammation group
			Negative control group	1	1
ATAVPIIFF(1mg/ml)	1.0794±0.0732**	1.117±0.0537**

Note: indicates a significant difference (P <0.05) compared to the negative control; indicates that there is a significant difference (P <0.01) compared with the negative control group

The results are shown in Table 2, and it is understood from Table 2 that macrophages were proliferated in both the normal group and the inflammatory group in the presence of 1mg/ml of the biologically active polypeptide ATAVPIIFF. And compared with a negative control group, the two groups have significant difference (P is less than 0.01). The result shows that the bioactive polypeptide ATAVPIIFF has obvious proliferation effect on in vitro macrophage.

Example 3 anti-aging Activity assay of bioactive peptides

Experiment of effect of bioactive polypeptide ATAVPIIFF on spleen tissue structure in vivo

1. Experimental reagents and instruments:

reagent: experimental animal ICR mouse (male 5 weeks old), shanghai city experimental animal center; d-gal, national pharmaceutical group chemical reagents, Inc.; paraformaldehyde, chemical reagents of the national drug group, ltd; sodium chloride, national pharmaceutical group chemical reagents ltd; the biologically active polypeptide ATAVPIIFF obtained in example 1.

The instrument equipment comprises: model CM-230 Mohr super Water, Shanghai Mole scientific instruments, Inc.; millipore Milllex GP0.22 μm membrane filter, Millipore USA; GL-22M high-speed refrigerated centrifuge, Shanghai Luxiang apparatus centrifuge instruments Inc.

2. The experimental method comprises the following steps:

(1) model for animal aging

After one week of adaptive ICR mouse feeding, 4 groups of 6 mice were divided. Group 1 was a low dose intragastric group, mice were injected subcutaneously in the neck and back with D-gal at a dose of 500mg/kg daily and intragastric bioactive polypeptide ATAVPIIFF at a dose of 1 mg/day; group 2 was a high dose intragastric group, mice were injected subcutaneously in the neck and back with D-gal at a dose of 500mg/kg daily, and 3 mg/mouse a day dose of intragastric bioactive polypeptide ATAVPIIFF; group 3 was blank, mice grew normally; group 4 was an animal model group, and mice were injected subcutaneously into the neck and back with D-gal at a dose of 500mg/kg daily, and gavage with 0.9% normal saline; the injection period of D-gal and the gavage period of polypeptide were 42 days. The bedding is replaced every 3 days and the feed and distilled water supply is ensured. The weight of the mice was weighed once every five days, D-gal injection was prepared according to the weight of the mice, and the D-gal injection was filtered through a 0.22 μm syringe filter to ensure sterility.

(2) Obtaining animal viscera

After the experiment period is finished, blood of a mouse is obtained by an eyeball-picking blood-taking method, the mouse is killed by breaking the neck after the blood is obtained, then a body of the mouse is placed on a low-temperature ice box, the brain, the spleen, the liver and the kidney of the mouse are quickly picked, the obtained viscera are placed in a pre-sterilized 1.5mL centrifuge tube, and all organ samples are stored in a refrigerator at the temperature of-80 ℃ for inspection. All procedures in the procedure of treating the experimental animals followed the guidance comments on the animals being treated in good care published by the department of scientific technology in 2006. The spleen of the mouse is directly soaked in a prepared 4% paraformaldehyde solution to fix the shape. The paraformaldehyde powder is relatively insoluble, and a trace amount of sodium bicarbonate can be added to adjust the pH value to be alkaline so as to aid dissolution. The preparation of the paraformaldehyde solution needs to be completed in a fume hood.

(3) Sample detection

Preparation of tissue sections: mouse spleen samples were fixed in 4% paraformaldehyde solution for at least 24 hours. The preparation of wax block, slicing and HE staining of spleen tissue were completed by Shanghai Weiao Biotech Co., Ltd.

3. Experimental results and analysis:

in this experiment, there were 4 groups of mice, of which the blank group did not undergo any external stimulation for normal growth, and the remaining 3 groups received long-term injections of D-gal. By observing spleen sections of different groups of mice by using an optical microscope, as can be seen from fig. 4, compared with spleen sections of each group of mice, compared with blank groups of mice, spleen red marrow and white marrow of animal model mice have fuzzy boundaries and atrophy of the white marrow, which indicates that long-term D-gal injection causes sugar metabolism pathways of the mice to be disordered, so that the antioxidant enzyme activity is reduced, peroxide is accumulated, and further spleen aging and atrophy are possibly caused. Compared with the mice of the animal model group, the spleen tissues of the mice of the gavage polypeptide group have lighter atrophy degree of the white marrow and have better boundary between the red marrow and the white marrow. This result suggests that the experimental animals are continuously stimulated by the senescence-causing factor throughout the injection cycle of D-gal, resulting in senescence and atrophy of the spleen. Therefore, from the aspect of tissue structure change, the bioactive polypeptide ATAVPIIFF has certain protective effect on spleen aging and atrophy caused by stimulation of an adverse factor.

Second, experiment of the action of bioactive polypeptide ATAVPIIFF on antioxidant level of internal organs

1. Experimental reagents and instruments:

reagent: experimental animal ICR mouse (male 5 weeks old), shanghai city experimental animal center; d-gal, national pharmaceutical group chemical reagents, Inc.; paraformaldehyde, chemical reagents of the national drug group, ltd; sodium chloride, national pharmaceutical group chemical reagents ltd; the biologically active polypeptide ATAVPIIFF obtained in example 1; BCA protein kit, Nanjing Kaikyi Biotech Co., Ltd; MDA lipid peroxide kit, south kyo kaiky biotechnology limited; SOD superoxide dismutase kit, Nanjing, biological technology Limited; T-AOC total antioxidant activity kit, Nanjing, established Biotechnology Limited.

2. The experimental method comprises the following steps:

(1) model for animal aging

(2) Obtaining animal viscera

(3) Sample detection

Grinding all organs to be detected in a low-temperature environment, diluting the ground organs into 10% tissue homogenate by using a 4 ℃ sterile PBS solution, centrifuging 4000g at 4 ℃, sucking and taking supernate, removing precipitates, and operating according to a kit instruction or placing the mixture in a refrigerator at minus 80 ℃ for detection.

3. Experimental results and analysis:

TABLE 3 variation of SOD content in different organs of each group of experimental animal mice

Note: significant differences (P <0.05) in plots compared to model group controls; the plot showed significant differences (P <0.01) compared to the model group control, as follows.

As can be seen from table 3, the SOD content in the liver and kidney of the mice in the peptide gavage group showed significant increase (P <0.01) compared to the mice in the animal model group. The fact that the mice in the polypeptide gavage group are stimulated by large dose of D-gal for a long time and the SOD enzyme system in the mice is not completely destroyed even if the D-gal is excessively injected indicates that the experimental animals are continuously stimulated by the aging-causing factors in the injection period to reduce the SOD content in different organs, but simultaneously ingest a certain amount of polypeptide ATAVPIIFF to have certain protection effect on oxidative damage in the mice.

TABLE 4 variation of MDA content in different organs of various groups of experimental animal mice

As can be seen from Table 4, the liver MDA content of the mice in the animal model group is 26.86 +/-7.04 nmol/L, and compared with the animal model group, the MDA content of the livers of the two groups of mice with the polypeptide gavage shows a significant difference (P < 0.01). As MDA can be used for estimating the accumulation condition of lipid peroxides in animals, it can be known that in the process of forming an aging model, sugar metabolism pathways of mice in an animal model group are disordered due to long-term injection of excessive D-gal, a large amount of free radicals are generated to cause oxidative damage, a large amount of lipid peroxides are generated in liver tissues of the mice, and MDA is used as the lipid peroxides, so that the increase of the content of the lipid peroxides in the animals can be laterally reflected to reduce the activity of antioxidant enzyme systems in the mice. The obvious reduction of the MDA content in the liver of the mice in the polypeptide gavage group shows that the ingestion of the polypeptide ATAVPIIFF can effectively protect important tissues and organs from being stimulated by adverse factors to generate a large amount of lipid peroxides.

TABLE 5 Change in T-AOC in groups of Experimental animals mice

As can be seen from Table 5, the liver T-AOC value of the mice in the animal model group is 0.68 +/-0.21U/mgprot, and compared with the mice in the model group, the mice in the high-dose and low-dose gavage groups of the polypeptide show significant difference (P < 0.05); the kidney T-AOC content of the blank group of mice is 0.61 +/-0.25U/mgprot, and compared with the mice in the animal model group, the mice in the low-dose intragastric group show significant difference (P <0.05), and the mice in the high-dose intragastric group also show significant difference (P < 0.01). The results show that in the whole experimental period, because the experimental animals are continuously stimulated by the senescence-causing factors, the liver and kidney tissues of the mice in the animal model group are damaged, so that the total antioxidant capacity of the mice is reduced. Compared with animal model group and blank group, the total antioxidant capacity of main organs of mice in polypeptide gavage group is always maintained at a higher level in the process of being stimulated by aging-causing factors, which indicates that the animal body and the main organs thereof have higher self-protection function by taking the bioactive polypeptide ATAVPIIFF.

Third, experiment of biologically active polypeptide ATAVPIIFF on action of immunocytokines in serum

1. Experimental reagents and instruments:

reagent: experimental animal ICR mouse (male 5 weeks old), shanghai city experimental animal center; d-gal, national pharmaceutical group chemical reagents, Inc.; paraformaldehyde, chemical reagents of the national drug group, ltd; sodium chloride, national pharmaceutical group chemical reagents ltd; the biologically active polypeptide ATAVPIIFF obtained in example 1; BCA protein kit, Nanjing Kaikyi Biotech Co., Ltd; ELISA cytokine Rapid kits (TNF-. alpha., IL-2, IL-6 and IL-10), Wuhan Dr bioengineering, Inc.

2. The experimental method comprises the following steps:

(1) model for animal aging

(2) Obtaining animal viscera and serum

After the experiment period is finished, blood of the mouse is obtained by an eyeball-picking blood-taking method, the mouse is killed by breaking the neck after the blood is obtained, then the body of the mouse is placed on a low-temperature ice box, the blood of the mouse is stood for 1 hour at room temperature, and then is centrifuged for 15min at 3000g, and serum is separated. The serum was stored in a freezer at-80 ℃ for testing. All procedures in the procedure of treating the experimental animals followed the guidance comments on the animals being treated in good care published by the department of scientific technology in 2006. The spleen of the mouse is directly soaked in a prepared 4% paraformaldehyde solution to fix the shape. The paraformaldehyde powder is relatively insoluble, and a trace amount of sodium bicarbonate can be added to adjust the pH value to be alkaline so as to aid dissolution. The preparation of the paraformaldehyde solution needs to be completed in a fume hood.

(3) Sample detection

According to the instruction of the kit, firstly, a standard curve is drawn, standard powder is prepared into a solution of 1000pg/mL by using a standard diluent, and then the solution is continuously diluted into different concentrations of 500pg/mL, 250pg/mL, 125pg/mL, 62.5pg/mL, 31.3pg/mL, 15.6pg/mL and the like. Each concentration gradient solution was pipetted at 100. mu.L in an antibody-coated microplate. And (3) sucking 100 mu L of mouse serum sample, and adding the mouse serum sample into the same enzyme label plate (if the serum sample is insufficient, the mouse serum sample can be diluted properly and then needs to be converted proportionally when being detected and calculated). The plate was covered and incubated at 37 ℃ for 90 min. After the reaction is finished, carefully throwing off the liquid in the ELISA plate, placing the ELISA plate on absorbent paper, carefully beating the absorbent paper, and removing the redundant liquid. Adding preheated biotin anti-antibody working solution into each hole of the ELISA plate according to 100 mu L of each hole, and reacting for 60min at 37 ℃. After the reaction was completed, the reaction solution was washed 3 times with 0.01M PBS, 100. mu.L of PBS was added to each well, and the solution was removed after soaking for 1min, and the reaction was repeated 3 times. The preheated ABC working solution is added into each hole according to the volume of 0.1ml in turn, and the reaction is carried out for 30min at the temperature of 37 ℃. After the reaction, the reaction mixture was washed with 0.01M PBS for 5 times, and soaked for about 1min each time. Adding TMB color development solution which is balanced at 37 ℃ for 30min in turn according to 90 mu L per hole, and reacting for 8-12min at 37 ℃ in a dark place. TMB stop solution was added in an amount of 0.1ml per well in this order, and the color blue was immediately changed to yellow, and the OD value was measured at 450nm using a microplate reader. The standard protein of the cell factor is serially diluted in known concentration, an OD value is measured, a standard curve is drawn, and the content of the cell factor in the specimen can be calculated according to the standard curve.

3. Experimental results and analysis:

TABLE 6 cytokine profile in serum of groups of mice

From Table 6, FIG. 5 and FIG. 6, it can be found that the IL-6 and TNF- α contents in the mice of the model group in the experiment are 168.01 + -26.38 pg/mL and 4.34 + -0.76 pg/mL respectively, which show significant increase (P <0.01) compared with the normal group, so that it can be considered that the mice of the model group have symptoms of the aging inflammation at the level of the cytokine due to the continuous injection of the aging-causing factor, and the IL-6 and TNF- α contents in the serum of the mice of the polypeptide gavage group are effectively controlled. According to the experimental result of the cell factors, the secretion levels of serum inflammatory cell factors IL-6 and TNF-alpha of the mice in the polypeptide gavage group are lower than those of the mice in the animal model group, and the oxidation damage of the mice caused by free radical attack and peroxidation product accumulation can be inhibited to a certain degree from the perspective of the oxidation damage; from the viewpoint of inflammation, the inflammation caused by oxidation of the mice is effectively inhibited; from the aging point of view, a series of senile diseases of mice caused by aging caused by long-term injection of D-gal are likely to be controlled.

From the results of fig. 7, it was found that IL-2 as a marker cytokine for aging did not show significant effect in both the model group and the gavage group in this experiment, and it is speculated that this index did not change due to the fact that the model used in this experiment was still different from natural aging or the molding cycle was not long enough. Meanwhile, from the results shown in FIG. 8, it was found that the bioactive polypeptide ATAVPIIFF could not affect the secretion of IL-10 in mice in this experiment in a period, and in the measurement of the serum IL-10 content in various mice, only the serum IL-10 content in the mice of the normal growth group was kept at a relatively low level, and the serum IL-10 content in the other groups was increased, which may be that the bioactive polypeptide ATAVPIIFF had no effect on the secretion pathway of IL-10.

The embodiments described above are described to facilitate an understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention based on the disclosure of the present invention.

Sequence listing

<110> Shanghai university of transportation; zhejiang ghui peptide Life health science and technology Limited

<120> a bioactive polypeptide ATAVPIIFF, and its preparation method and application

<160> 3

<170> SIPOSequenceListing 1.0

<210> 1

<211> 9

<212> PRT

<213> Artificial Sequence (Artificial Sequence)

<400> 1

Ala Thr Ala Val Pro Ile Ile Phe Phe

1 5

<210> 2

<211> 27

<212> DNA

<213> Artificial Sequence (Artificial Sequence)

<400> 2

ctactgctgt tcctattata ttttttg 27

<210> 3

<211> 319

<212> PRT

<213> Artificial Sequence (Artificial Sequence)

<400> 3

Leu Leu Asp Gln Phe Lys Ile Ser His Asp Pro Asn Pro Glu Val Arg

1 5 10 15

Ala Thr Ala Val Pro Ile Ile Phe Phe Glu Thr Arg Lys Gln Gly Glu

20 25 30

Arg Ile Phe His Gly Tyr Gly Val Ile Lys Asn Val Lys Leu Val Thr

35 40 45

Gln Tyr Thr Gly Ser Gly Ala Asp Lys Ala Tyr Phe Ser Asn Tyr Leu

50 55 60

Phe Thr Phe Cys Val Phe Ser Met Lys Lys Glu Gln Glu Gly Phe Asp

65 70 75 80

Trp Ser Trp Ile Glu Ala Arg Lys Gln Ala Ala Lys Asp Lys Asn Phe

85 90 95

Leu Ser Leu Ala Asn Ala Leu Ala Pro Lys Glu Trp Lys Phe Trp Ile

100 105 110

Arg Thr Gly Asp Leu Glu Lys Val Arg Arg Lys Val Tyr Gly Arg Ser

115 120 125

Thr Ser Lys Lys Glu Glu Gln Leu Pro Thr Pro Gly Ser Ala Asp Asp

130 135 140

Lys Ile Leu Asn Gln Ile Tyr Glu Tyr Tyr Arg Lys Lys Asp Asn Ser

145 150 155 160

Lys Ala His Ser Gly Asp Phe Glu Phe Glu Gly Leu Ala Lys Glu Ile

165 170 175

Thr Arg Leu Ile Ile Gly Asp Ala Cys His Asp Gly Trp Val Thr Lys

180 185 190

Ser Ser Gly Asp Gly Gly Tyr Asp Phe Val Leu Arg Val Asp Ile Gly

195 200 205

Thr Lys Gly Ile Ser Gln Val Arg Gln Val Val Leu Gly Gln Ala Lys

210 215 220

Cys Tyr Arg Arg Asp Gln Arg Ile Thr Gly Glu Ala Val Asp Arg Val

225 230 235 240

Val Ala Arg Leu Lys Arg Gly Trp Ile Ala Ala Phe Val Thr Thr Ser

245 250 255

Phe Phe Ser Asp Pro Ala Gln Arg Glu Ile Leu Glu Asp Asp Tyr Pro

260 265 270

Ile Met Leu Ile Ser Gly Lys Gln Val Ala Gln Thr Val Arg Lys Tyr

275 280 285

Ile Tyr Glu Lys Asn Ile Thr Leu Arg Glu Tyr Leu Asp Ser Leu Ser

290 295 300

Arg Asp Gln Ser Phe Lys Ser Pro Glu Asp Ile Leu Lys Glu Glu

305 310 315

Claims

1. A biologically active polypeptide ATAVPIIFF, having the amino acid sequence Ala-Thr-Ala-Val-Pro-Ile-Ile-Phe-Phe.

2. A nucleotide fragment encoding the biologically active polypeptide ATAVPIIFF of claim 1, wherein the nucleotide fragment has the sequence set forth in SEQ ID NO: 2, respectively.

3. The method of claim 1, wherein the biologically active polypeptide ATAVPIIFF is synthesized by genetic engineering methods or is prepared directly by chemical synthesis.

4. The use of the biologically active polypeptide ATAVPIIFF of claim 1, wherein the biologically active polypeptide ATAVPIIFF is used in the preparation of a food, a health product, a pharmaceutical or a cosmetic product with immunomodulatory activity.

5. The use of the biologically active polypeptide ATAVPIIFF of claim 1, wherein the biologically active polypeptide ATAVPIIFF is used in the preparation of a food, a health product or a pharmaceutical product with anti-aging properties.

6. The use of the biologically active polypeptide ATAVPIIFF of claim 1, wherein the biologically active polypeptide ATAVPIIFF is used in the preparation of a food, a health product or a pharmaceutical product with immunomodulatory and anti-aging effects.

7. An immunomodulatory product comprising the biologically active polypeptide ATAVPIIFF of claim 1; the immunoregulation product comprises an immunoregulation food, an immunoregulation health product, an immunoregulation medicament or an immunoregulation cosmetic.

8. An anti-aging product comprising the biologically active polypeptide ATAVPIIFF of claim 1; the anti-aging product comprises anti-aging food, anti-aging health care products or anti-aging drugs.

9. A product having immunomodulatory and anti-aging properties, comprising the biologically active polypeptide ATAVPIIFF of claim 1; the product with immunoregulation function and anti-aging function comprises food, health product or medicine.