CN108794604B

CN108794604B - Bioactive polypeptide SVAPAAAGIN, and preparation method and application thereof

Info

Publication number: CN108794604B
Application number: CN201810717782.9A
Authority: CN
Inventors: 张少辉; 亚辛·黑马尔; 洪志骏; 陈平; 陈承余; 林学海; 张伯宇; 占文静
Original assignee: Shanghai Platinum Hui Biological Technology Co Ltd; Zhejiang Peptide Life Health Science And Technology Co Ltd
Current assignee: Shanghai Platinum Hui Biological Technology Co Ltd; Zhejiang Peptide Life Health Science And Technology Co Ltd
Priority date: 2018-06-29
Filing date: 2018-06-29
Publication date: 2020-02-07
Anticipated expiration: 2038-06-29
Also published as: CN108794604A

Abstract

The invention relates to the field of protein, in particular to a bioactive polypeptide SVAPAAAGIN, a preparation method and application thereof, wherein the amino acid sequence of the bioactive polypeptide SVAPAAAGIN is Ser-Val-Ala-Pro-Ala-Ala-Ala-Gly-Ile-Asn. Through in vitro immune function regulation experiments and in vivo anti-aging experiments, the polypeptide SVAPAAAGIN is verified to have better immune function regulation and anti-aging activity, on one hand, the bioactive polypeptide SVAPAAAGIN 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 SVAPAAAGIN, and preparation method and application thereof

Technical Field

The invention relates to the field of proteins, in particular to a bioactive polypeptide SVAPAAAGIN, 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 the changes of antioxidant level, organ tissues and immune factors, wherein the cytokines are changed in a complex way, such as proinflammatory cytokines IL-6, IL-4, TNF- α and the like show a growing trend, and IL-6 and TNF-a are considered to play important roles in the process of the senile diseases.

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 SVAPAAAGIN, 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 SVAPAAAGIN having an amino acid sequence Ser-Val-Ala-Pro-Ala-Ala-Ala-Gly-Ile-Asn, as shown in SEQ ID NO: 1 is shown.

Preferably, the bioactive polypeptide is derived from lactobacillus helveticus mycoprotein. Specifically from LBH-1221. sub.m.1131 LBH-1221. sub.g.1131 ORF LBH-1221. sub.g.1131 LBH-1221. sub.m.1131 type complete len:119(+) LBH-1221: 598-. LBH-1221. sub.m.1131 LBH-1221. sub.g.1131 ORF LBH-1221. sub.g.1131 LBH-1221. sub.m.1131type complete len:119(+) LBH-1221: 598-954(+) protein amino acid sequence is as shown in SEQ ID NO: 3, respectively.

The amino acid sequence of LBH _1221| m.1131 LBH _1221| g.1131 ORF LBH _1221| g.1131LBH _1221| m.1131type complete len:119(+) LBH _1221:598-954(+) protein and the corresponding nucleotide sequence are known techniques, and a fragment of nucleotides encoding amino acid residues 104 to 113 of this protein encodes the mature biologically active polypeptide SVAPAAAGIN.

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 SVAPAAAGIN, the sequence of which is: 5'-ctg ttg ctc ctg cag ctg ctg gca taa att-3', as shown in SEQ ID NO: 2, respectively.

In the third aspect of the invention, the preparation method of the bioactive polypeptide SVAPAAAGIN 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 SVAPAAAGIN 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 SVAPAAAGIN 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 SVAPAAAGIN in preparing food, health care products or medicines with immune regulation function and anti-aging function.

Specifically, the bioactive polypeptide SVAPAAAGIN 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 SVAPAAAGIN degraded by gastrointestinal tract still has bioactivity, the bioactive polypeptide SVAPAAAGIN 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 SVAPAAAGIN or a derivative of said biologically active polypeptide SVAPAAAGIN; the immunoregulation product comprises immunoregulation food, immunoregulation health-care products, immunoregulation medicaments or immunoregulation cosmetics; the derivative of the biologically active polypeptide SVAPAAAGIN 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 SVAPAAAGIN.

In an eighth aspect of the invention, there is provided an anti-aging product comprising the biologically active polypeptide SVAPAAAGIN or a derivative of the biologically active polypeptide SVAPAAAGIN; the anti-aging product comprises anti-aging food, anti-aging health care product or anti-aging drug; the derivative of the biologically active polypeptide SVAPAAAGIN 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 SVAPAAAGIN.

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 SVAPAAAGIN or a derivative of the bioactive polypeptide SVAPAAAGIN; products with immunoregulatory and anti-aging functions include foods, health products or drugs; the derivative of the biologically active polypeptide SVAPAAAGIN 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 SVAPAAAGIN.

The bioactive polypeptide SVAPAAAGIN has the following beneficial effects: the bioactive polypeptide SVAPAAAGIN has good activity of regulating the immunity of the organism and anti-aging activity; on one hand, the bioactive polypeptide SVAPAAAGIN 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 870.4579);

FIG. 2: a secondary mass spectrum of a fragment with a mass to charge ratio of 870.4579;

FIG. 3: fragmentation of polypeptide az and by with mass-to-charge ratio of 870.4579;

FIG. 4: the effect of biologically active polypeptide SVAPAAAGIN on female drosophila survival;

FIG. 5: hydrogen peroxide (H)₂O₂) And (5) acute experiments.

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, 1989and Third edition, 2001; ausubel et al, Current PROTOCOLS Inmolecular BIOLOGY, John Wiley & Sons, New York, 1987and periodic updates; the series METHODS IN ENZYMOLOGY, Academic Press, San Diego; wolffe, CHROMATINSTRUCUTURE AND FUNCTION, Third edition, Academic Press, San Diego, 1998; (iii) Methods Inenzymolygy, 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 SVAPAAAGIN

Synthesis of bioactive peptide

1. 3g 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 Ser and a proper amount of 1-hydroxy-benzotriazole (HOBT) into a 50ml centrifuge tube, adding 20ml of DMF to dissolve the amino acid Ser 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 Val, Ala, Pro, Ala, Gly, Ile and Asn are sequentially grafted 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 SVAPAAAGIN 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 SVAPAAAGIN, 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 870.4579Da, and the retention time is 48.3 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 870.4579Da obtained by analysis and calculation of Mascot software is Ser-Val-Ala-Pro-Ala-Ala-Gly-Ile-Asn (SVAPAAAGIN) and is marked as SEQ ID NO: 1. the fragment corresponds to the residue sequence at positions 104-113 of LBH _1221| m.1131 LBH _1221| g.1131 ORF LBH _1221| g.1131LBH _1221| m.1131type complete len:119(+) LBH _1221: 598-: 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 SVAPAAAGIN

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 SVAPAAAGIN 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; DragonWellscan MK3 microplate reader, Labsystems corporation; 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 blank controlA light value; 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 SVAPAAAGIN on in vitro lymphocyte proliferation

Experiment grouping	Stimulation index SI
		Negative control group	1
SVAPAAAGIN	1.172±0.036*

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 SVAPAAAGIN is 100 μ g/mL, the stimulation index of the bioactive peptide SVAPAAAGIN is greater than that of BSA, which indicates that SVAPAAAGIN can stimulate the proliferation of mouse lymphocytes in vitro to some extent. And SVAPAAAGIN reached a stimulation index of 1.172, which was significantly different from that of the negative control group (P < 0.05). Therefore, the active polypeptide SVAPAAAGIN 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 SVAPAAAGIN

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 SVAPAAAGIN 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 WellscanMK3 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 SVAPAAAGIN (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 SVAPAAAGIN on macrophage proliferation in vitro

Experiment grouping	Normal group GI	GI inflammation group
			Negative control group	1	1
SVAPAAAGIN(1mg/ml)	1.0854±0.0612**	1.1498±0.0264**

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 SVAPAAAGIN. 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 SVAPAAAGIN has obvious proliferation effect on in vitro macrophage.

Example 3 anti-aging Activity assay of bioactive peptides

Experiment for improving survival ability of drosophila by bioactive polypeptide SVAPAAAGIN

1. Experimental reagents and instruments:

reagent: oregon K wild type drosophila melanogaster, university of shanghai transport college genetics laboratory; agar powder, national drug group chemical reagents limited; the biologically active polypeptide SVAPAAAGIN obtained in example 1.

The instrument equipment comprises: model CM-230 Mohr super Water, Shanghai Mole scientific instruments, Inc.; model G136T Zealway intelligent high temperature sterilization pot, xiamen micro instrument science and technology ltd; BJ-CD SERIES Bioincubators, Shanghai Bingbo industries, Inc.; GRX-9073 hot air sterilization cabinet, Shanghai-constant technology, Inc.

2. The experimental method comprises the following steps:

taking fruit flies as an experimental model: collecting newly emerged fruit fly imagoes within 8 hours, randomly transferring the imagoes into each experimental group after anesthesia, wherein each sex of each group is 100, each group is provided with 3 parallels, a control group is given with a common corn flour culture medium, and the experimental groups are SVAPAAAGIN bioactive peptide-corn culture media containing 0.05mg/ml, 0.5mg/ml and 1mg/ml respectively. Fresh medium was changed every 2 days, and the number of deaths of flies of different genders was observed and recorded every day until all flies died. And (4) drawing a survival curve of the fruit flies, and calculating the average life and the maximum life of the fruit flies of different sexes (taking 5 fruit flies dead finally for statistics).

3. Experimental results and analysis:

the results of the study of the life of drosophila fed with bioactive peptides of different concentrations in this experiment are as follows: from FIG. 4, it can be seen that SVAPAAAGIN fed at a concentration of 0.05mg/ml did not significantly change the survival rate of male drosophila relative to the blank control group, whereas the survival rate of female drosophila was improved at the same time point when the peptide concentration reached 0.5mg/ml and 1mg/ml, but the difference was not significant.

TABLE 3-1 SVAPAAAGIN Effect on the longevity of male Drosophila

Note: significant differences (P <0.05) in the plots compared to the placebo group; the same applies below.

TABLE 3-2 SVAPAAAGIN Effect on female Drosophila longevity

From table 3-1, it can be seen that the average life span of the male drosophila in the low dose group is not significantly changed relative to the blank control group, but the average life span of the male drosophila in the medium dose group and the high dose group is improved, namely 16.51% and 11.77% respectively, but only the medium dose group generates a significant difference (p <0.05), which indicates that the average life span of the male drosophila in the medium dose group is significantly improved. Meanwhile, the half death time of the drosophila flies in the medium-dose group and the high-dose group is improved, but no obvious difference exists in the aspect of the longest life. As can be seen from table 3-2, the low-, medium-and high-dose groups of female drosophila all improved in mean life, but did not produce significant differences. However, the longest life of both the medium and high dose groups was improved, 5 and 4 days longer than the blank control group, respectively, and a significant difference was generated (P < 0.05).

The results of this experiment demonstrate that bioactive polypeptide SVAPAAAGIN can increase the average and maximum life span of Drosophila at certain concentrations, but is related to concentration and sex. The phenomenon related to the concentration and strain of the test substance is probably because SVAPAAAGIN is involved in part of the biological metabolism of the fruit flies, or the effect of prolonging the life of the fruit flies is achieved by improving the antioxidant system of the fruit fly tissues. The metabolism of fruit flies in different strains can be differentiated, so that the results are different. The sex difference is probably because the female fruit flies have certain conservation and resistance to the external environment, so SVAPAAAGIN is not obvious in prolonging the life of the female fruit flies.

Second, experiment for improving reproductive capacity of drosophila by bioactive polypeptide SVAPAAAGIN

1. Experimental reagents and instruments:

2. The experimental method comprises the following steps:

collecting newly emerged fruit fly imago within 8 hours, separately feeding male and female, adding SVAPAAAGIN solution with concentration of 0mg/ml, 0.05mg/ml, 0.5mg/ml and 1mg/ml into the culture medium, and continuously culturing for 12 days. Adult fruit flies cultured at the same concentration were collected on day 13 and transferred to new common culture flasks, each flask holding 1 female and 2 males (5 flasks per group), each flask being given the correct 24 hours for oviposition. Transferring the parent fruit fly into a new common culture bottle after spawning, continuously breeding and culturing the old culture bottle, counting the number of offspring after the larva eclosion, continuously measuring for 7 days, and repeating for 3 times.

3. Experimental results and analysis:

TABLE 4 fertility assay results

As can be seen from table 4, the low concentration experimental group showed no significant change in the fertility compared with the control group, but the medium and high dose experimental groups showed significantly improved drosophila fertility compared with the blank control group (P < 0.05). Indicating that SVAPAAAGIN at a certain concentration can promote the reproductive capacity of fruit flies. The results of this experiment show that the prolongation of the life span of drosophila is the result of the direct action of SVAPAAAGIN, and not the secondary physiological effect of SVAPAAAGIN by reducing fertility. Meanwhile, SVAPAAAGIN is safe to fruit flies and has no toxic hazard.

Thirdly, acute oxidation experiment of hydrogen peroxide by bioactive polypeptide SVAPAAAGIN

1. Experimental reagents and instruments:

reagent: oregon K wild type drosophila melanogaster, university of shanghai transport college genetics laboratory; agar powder, national drug group chemical reagents limited; hydrogen peroxide, shanghai Lingfeng Chemicals, Inc.; the biologically active polypeptide SVAPAAAGIN obtained in example 1.

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

2. The experimental method comprises the following steps:

collecting newly emerged fruit fly imagoes within 8 hours, randomly transferring the imagoes into each experimental group after anesthesia, taking a peptide concentration culture medium with a better result in a life test, setting a blank control group and the experimental group, and giving a common corn flour culture medium to the control group. Each group of male and female sex fruit flies was 50, and the fruit flies were cultured for three weeks. Then, 5 male and 5 female fruit flies each time were transferred to a new container containing a paper disc containing 300. mu.L of a 5% sucrose solution and 1ml of 30% hydrogen peroxide, and the blank and experimental groups were exposed to the toxic peroxide environment generated by this hydrogen peroxide, and 10 replicates of each group were set up and observed for their antioxidant capacity. The number of fruit fly deaths and sex were recorded every 4 hours until all of the flies had died.

3. Experimental results and analysis:

as can be seen from fig. 5(a), for male fruit flies fed at SVAPAAAGIN, the survival rate of the male fruit flies was higher than that of the fruit flies not fed at SVAPAAAGIN at each time point, and the survival time was improved compared with that of the blank control group, indicating that the antioxidant capacity of the male fruit flies was improved after SVAPAAAGIN was fed. In fig. 5(B), the survival rate of the female fruit flies fed with SVAPAAAGIN in the high-concentration hydrogen peroxide environment for 15h is obviously higher than that of the control group, which shows that the antioxidant capacity of the female fruit flies is improved in this period. However, the survival curves of the later experimental group and the control group are basically coincident, which shows that the antioxidant capacity of the female drosophila fed with SVAPAAAGIN is gradually weakened, and the female drosophila fed with SVAPAAAGIN has no difference with the control group after a certain time. The experimental result shows that SVAPAAAGIN can improve the antioxidant capacity of fruit flies. According to H₂O₂As a result of acute toxicity test, it is presumed that SVAPAAAGIN might increase the H pair of fruit fly by regulating catalase CAT activity₂O₂Resistance to injury.

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> Zhejiang ghui peptide Life health science and technology Limited; shanghai platinum Biotech Ltd

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

<160>3

<170>SIPOSequenceListing 1.0

<210>1

<211>10

<212>PRT

<213> Artificial Sequence (Artificial Sequence)

<400>1

Ser Val Ala Pro Ala Ala Ala Gly Ile Asn

1 5 10

<210>2

<211>30

<212>DNA

<213> Artificial Sequence (Artificial Sequence)

<400>2

ctgttgctcc tgcagctgct ggcataaatt 30

<210>3

<211>118

<212>PRT

<213> Artificial Sequence (Artificial Sequence)

<400>3

Met Arg Tyr Ile Gly Val Leu Ile Ser Gly Phe Met Ala Gly Leu Gly

1 5 10 15

Gly Ala Val Phe Ala Gln Ser Ile Ser Gly Asn Phe Ser Ile Ser Thr

20 25 30

Ile Val Gly Gln Gly Phe Ile Ala Leu Ala Ala Val Ile Phe Gly Lys

35 40 45

Trp Asn Pro Ile Gly Ala Met Leu Ser Ser Leu Phe Phe Gly Phe Ala

50 55 60

Gln Ser Leu Ser Ile Ile Gly Asn Gln Leu Pro Gly Phe Glu Lys Ile

65 70 75 80

Pro Thr Val Tyr Met Gln Ile Thr Pro Tyr Val Ile Thr Ile Val Val

85 90 95

Leu Val Ile Phe Leu Gly Lys Ser Val Ala Pro Ala Ala Ala Gly Ile

100 105 110

Asn Tyr Ile Lys Ser Lys

115

Claims

1. A biologically active polypeptide SVAPAAAGIN, having an amino acid sequence Ser-Val-Ala-Pro-Ala-Ala-Ala-Gly-Ile-Asn.

2. A nucleotide fragment encoding the biologically active polypeptide SVAPAAAGIN 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 SVAPAAAGIN is synthesized by genetic engineering methods or is prepared directly by chemical synthesis.

4. The use of the biologically active polypeptide SVAPAAAGIN of claim 1, wherein the biologically active polypeptide SVAPAAAGIN 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 SVAPAAAGIN of claim 1, wherein the biologically active polypeptide SVAPAAAGIN 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 SVAPAAAGIN of claim 1, wherein the biologically active polypeptide SVAPAAAGIN 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 SVAPAAAGIN 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 SVAPAAAGIN 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 SVAPAAAGIN of claim 1; the product with immunoregulation function and anti-aging function comprises food, health product or medicine.