Bioactive peptide with weight losing effect, preparation and application of bioactive peptide

Abstract

The invention discloses a bioactive peptide with a weight losing effect, a preparation and application of the bioactive peptide, and belongs to the technical field of bioactive peptides. The amino acid sequence of the bioactive peptide with the weight losing effect is at least one of QLGIK and NTDKQVT. According to the invention, two bioactive peptides with a weight-losing effect are separated and purified from defatted euphausia superba protein, and components and sequences of the bioactive peptides are preliminarily identified through a liquid chromatography-mass spectrometry technology. According to the present invention, chemical synthesis is performed according to the identified peptide fragment sequence, and the weight reducing effects of the synthesized single peptide fragment and the compounded peptide fragment are detected, such that the bioactive peptides have good pancreatic lipase and alpha-amylase inhibition activity so as to provide good application prospects in the preparation of the weight reducing effect product, and a foundation is laid for high-added-value utilization of the euphausia superba protein and promotion of research, development and application of functional active peptides.

Description

Technical Field

[0001] The invention belongs to the technical field of bioactive peptides, and in particular relates to a bioactive peptide with weight loss effect, a preparation and application thereof. Background Art

[0002] The fat component in food is mainly triglycerides. After the food is ingested by the body, the water-insoluble fat is first emulsified into chylomicrons in the stomach so that it can be hydrolyzed by water-soluble lipase in the duodenum. Then the lipase hydrolyzes to produce fatty acids and monoglycerides, which are transformed into soluble mixed micelles by bile acid micelles, and then absorbed in the gastrointestinal tract, and the body resynthesizes fat. If too much high-fat food is consumed, it will eventually cause the accumulation of body fat and form obesity. In order to effectively prevent, control and treat obesity and reduce the adverse effects of obesity on the body, people have studied and tried many technical methods. Among them, the methods of controlling and treating obesity include physical and chemical methods. Physical methods refer to reducing fat by controlling diet, exercise and liposuction surgery; chemical methods mainly achieve the purpose of fat reduction through the chemical effects of some drugs and health foods. Among these technologies, taking weight loss drugs is an effective and convenient method to prevent or assist in the treatment of weight loss diseases.

[0003] At present, the functional food ingredients with lipid-lowering and weight-loss effects found in research include alkaloids, saponins, L-carnitine, enzymes, phenolphthalein and other substances. The weight-loss drugs composed of these active substances often achieve the purpose of controlling weight or losing weight by affecting gastrointestinal reactions and regulating the nervous system, reducing appetite or inhibiting the absorption of glucose, protein and lipid by the gastrointestinal tract. However, its side effects are often proportional to the dosage of the drug, that is, the larger the dosage, the greater the side effects, which can cause insomnia, fatigue, diarrhea, vomiting, increased blood pressure, etc., and even tachycardia, arrhythmia, heart failure. The side effects and safety hazards of weight-loss drugs have become the key factors limiting their application in the food industry.

[0004] The molecular weight of bioactive peptides is generally less than 6000Da, containing at least 2 amino acids, with good functionality and special activity, and can regulate the body's special physiological effects and life activities. They play a key role in a variety of biological processes, including hormone regulation, immune response and cell signal transduction. Natural bioactive peptides with weight loss effects isolated from natural substances, including functional peptides that inhibit the activity of pancreatic lipase and α-amylase and active peptides that reduce fat content by regulating appetite hormones and affecting the proliferation and differentiation of pre-adipocytes, are safe and side-effect-free functional ingredients with great potential to replace traditional weight loss drugs. Summary of the invention

[0005] In view of the problems existing in the prior art, the object of the present invention is to provide a bioactive peptide with weight loss effect, a preparation and application thereof.

[0006] In order to achieve the above object, the present invention adopts the following technical solution: A bioactive peptide with weight loss effect, wherein the amino acid sequence of the bioactive peptide with weight loss effect is at least one of QLGIK and NTDKQVT.

[0007] The application of the above bioactive peptides with weight loss effect in the preparation of products with weight loss effect.

[0008] Based on the above scheme, the product is food, medicine or health care product.

[0009] Based on the above solution, the product further comprises excipients acceptable to food, pharmacy or health care products.

[0010] A bioactive peptide preparation with weight loss effect, wherein the active ingredient of the preparation is at least one of the bioactive peptides shown by QLGIK and NTDKQVT.

[0011] Based on the above scheme, the concentration of the active ingredient in the bioactive peptide preparation with weight loss effect is 0.5 mg / mL.

[0012] Based on the above scheme, the weight loss effect is having pancreatic lipase and α-amylase inhibitory activity.

[0013] Advantages of the technical solution of the present invention The present invention uses defatted Antarctic krill protein as raw material, separates bioactive peptides with weight loss efficacy through enzymatic hydrolysis, ultrafiltration, gel chromatography, and liquid chromatography separation technology, and preliminarily identifies its components and sequences through liquid chromatography-mass spectrometry technology. Chemical synthesis is performed based on the identified peptide sequences to obtain two bioactive peptides QLGIK and NTDKQVT with weight loss efficacy. According to the test, the two peptides and their composite peptides have good pancreatic lipase and α-amylase inhibitory activities, and have good application prospects in the preparation of products with weight loss efficacy, laying a foundation for the high added value utilization of Antarctic krill protein and promoting the research and development and application of functional active peptides.

[0014] Traditional weight loss drugs, such as orlistat, Qsymia, phenolphthalein, etc., may cause endocrine disorders, nutritional imbalance, and increased nerve excitability. Long-term use will affect the normal secretory function of the gastrointestinal tract and pose potential health risks. The bioactive peptides separated and obtained by the present invention have good weight loss effects. The raw materials are natural and non-toxic Antarctic krill protein, which is green and safe. No organic reagents are introduced during the preparation process, there are no side effects, the operation is simple, and the equipment requirements are low. It has the potential to be used as a new type of weight loss product in the field of health food. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Effects of different proteases on the hydrolysis degree of Antarctic krill protein (data marked with different lowercase letters are significantly different P<0.05); Figure 2 Effects of different proteases on the inhibitory activity of pancreatic lipase in Antarctic krill enzymatic hydrolysates (data marked with different lowercase letters are significantly different, P<0.05); Figure 3 The inhibitory activity of components with different molecular weights after ultrafiltration on pancreatic lipase (the data marked with different lowercase letters are significantly different, P<0.05); Figure 4 The inhibitory activity of components with different molecular weights after ultrafiltration on α-amylase (the data marked with different lowercase letters are significantly different, P<0.05); Figure 5 The components were separated and purified by gel filtration chromatography; Figure 6 The inhibitory activity of each fraction on pancreatic lipase after gel filtration chromatography (the data marked with different lowercase letters are significantly different, P<0.05); Figure 7 The inhibitory activity of each component on α-amylase after gel filtration chromatography (the data marked with different lowercase letters are significantly different P<0.05); Figure 8 Secondary mass spectrum of Antarctic krill peptide QLGIK; Fig. 9 The secondary mass spectrum of the Antarctic krill peptide NTDKQVT; Fig.10 Primary mass spectrum of the biosynthetic peptide QLGIK; Fig.11 Primary mass spectrum of the biosynthetic peptide NTDKQVT; Fig.12 The inhibitory activity of each biosynthesized peptide fragment on pancreatic lipase (the data marked with different lowercase letters are significantly different P<0.05); Fig.13The inhibitory activity of each peptide fragment on α-amylase after biosynthesis (the data marked with different lowercase letters are significantly different, P<0.05). DETAILED DESCRIPTION

[0016] The terms used in the present invention, unless otherwise specified, generally have the meanings commonly understood by those of ordinary skill in the art. The present invention will be further described in detail below in conjunction with specific examples and with reference to data. The following examples are intended to illustrate the present invention and are not intended to limit the scope of the present invention in any way.

[0017] The experimental methods in the following examples, unless otherwise specified, are all conventional methods, and are performed according to the techniques or conditions described in the literature in the field or according to the product instructions. The experimental materials, reagents, drugs, etc. used in the following examples, unless otherwise specified, can all be purchased through general channels.

[0018] In the following embodiments, 1. Determination of the degree of hydrolysis of Antarctic krill protein: 80 mg of OPA was dissolved in 2 mL of anhydrous ethanol, 200 μL of β-mercaptoethanol, 5 mL of 10% SDS (w / v) and 92.8 mL of 0.1 mol / L sodium tetraborate to prepare 100 mL of OPA reagent solution. 40 μL of Antarctic krill enzymatic hydrolysate was mixed with 4 mL of OPA reagent and incubated at room temperature for 2 min, and the absorbance at a wavelength of 340 nm was measured. Antarctic krill protein was placed in 6 mol / L HCl and reacted at 115 ° C for 24 h. The number of free amino groups was determined using the serine standard curve as the number of free amino acids produced by complete hydrolysis of Antarctic krill protein.

[0019] The degree of hydrolysis of Antarctic krill protein is calculated according to the following formula:

[0020] Where: (NH2) t Indicates the amount of free amino acids in the enzymatic hydrolysis product at time t; (NH2) t0 Indicates the amount of free amino acids that have not been hydrolyzed by enzymes; (NH2) T Represents the amount of free amino acids after complete hydrolysis.

[0021] 2. Determination of pancreatic lipase inhibitory activity: With p-nitrophenylbutyrate (0.005 mol / L) as substrate, Antarctic krill enzymatic hydrolysate and pancreatic lipase (1.25 mg / mL) were taken in PBS (0.01 mol / L, pH 7.4), placed in a 96-well plate and the reaction mixture volume was adjusted to 150 μL with PBS, incubated at 37°C for 30 min, and a multifunctional microplate reader was selected to measure the absorbance at a wavelength of 405 nm. The components of the reaction system are shown in Table 1.

[0022] Table 1 Composition of various systems for pancreatic lipase inhibition activity assay

[0023] Result calculation: The inhibitory effect of Antarctic krill enzymatic hydrolysate on lipase activity was calculated according to the following formula:

[0024] Wherein, I: inhibition rate of Antarctic krill enzymatic hydrolysate on pancreatic lipase; A: blank tube; a: blank control tube; B: inhibition tube; b: background control tube; “ / ” means no sample was added.

[0025] 3. α-Amylase inhibitory activity determination method The activity of α-amylase was determined by spectrophotometry using soluble starch as substrate and 3,5-dinitrosalicylic acid (DNS) as colorimetric agent. 0.25 mL 4 units / mL α-amylase and 0.25 mL Antarctic krill hydrolysate were added to 0.5 mL pH 6.9 0.2 mol / L PBS, incubated at 37 °C for 10 min, then 0.5 mL 1% soluble starch solution was added, reacted accurately for 5 min, and finally 1 mL DNS reagent was added, boiled for 10 min, cooled rapidly with running water, diluted five times, and the absorbance was measured at a wavelength of 540 nm. The components of the reaction system are shown in Table 2.

[0026] Table 2 Composition of various systems for α-amylase activity determination

[0027] Result calculation: The inhibitory effect of Antarctic krill enzymatic hydrolysate on α-amylase activity was calculated according to the following formula:

[0028] Wherein, I: inhibition rate of Antarctic krill enzymatic hydrolysate on α-amylase; A: blank tube; a: blank control tube; B: inhibition tube; b: background control tube; “ / ” means no sample was added.

[0029] The Antarctic krill used in the examples were purchased from Qingdao Antarctic Weikang Biotechnology Co., Ltd. (Qingdao, China).

[0030] Example 1 A bioactive peptide with weight loss effect, the amino acid sequence of the bioactive peptide is shown as SEQ ID NO: 1 or SEQ ID NO: 2.

[0031] SEQ ID NO: 1: QLGIK; SEQ ID NO:2: NTDKQVT.

[0032] Example 2 The method for extracting bioactive peptides with weight loss effects from Antarctic krill is as follows: (1) Weigh 100 g of washed, headless and shelled Antarctic krill meat, place it in a beaker, and add deionized water (4°C) with a liquid-to-solid ratio of 3.17 mL / g to homogenize. Subsequently, adjust the pH to 11.38 with 2 mol / L sodium hydroxide, let it stand for 0.5 h, and centrifuge it at 10,000 g for 10 min at 4°C to obtain the supernatant. Repeat the entire extraction process 3 times. Finally, adjust the collected supernatant to pH 4.5 with 2 mol / L phosphoric acid, let it stand for 1.0 h, and centrifuge it at 10,000 g for 10 min at 4°C. Collect the precipitate and freeze-dry it at -80°C to store it as Antarctic krill protein.

[0033] (2) Weigh 5 g of the Antarctic krill protein extracted in step (1), add acetone solution at a ratio of 1:4 (w:v), stir with a constant temperature magnetic stirrer for 3 h, and then let it stand for 0.5 h until the liquid becomes clear. The upper red liquid is Antarctic krill oil. Pour it out and continue to add acetone. Stir for 2 h and then let it stand for 0.5 h. Pour out the upper red liquid and repeat the above steps until the upper liquid becomes colorless. Recover the defatted Antarctic krill protein in a fume hood.

[0034] (3) Weigh the defatted Antarctic krill protein prepared in step (2) and dissolve it in deionized water at a ratio of 2% (w / v). Add alkaline protease to the solution. The amount of alkaline protease added is 3000U per gram of Antarctic krill protein. After low-speed stirring, adjust the pH value to 9.5 and the temperature to 55°C. Place the solution in a constant temperature incubator for enzymatic reaction for 4 hours. After enzymolysis, heat the solution in boiling water for 15 minutes to inactivate the protease. The reaction is terminated and the solution is quickly cooled to 4.0°C with ice water. Centrifuge at 12000g for 15 minutes to retain the supernatant (called AKPH), freeze-dry, and obtain the Antarctic krill protease hydrolysis product.

[0035] Effects of different proteases on the hydrolysis degree and pancreatic lipase inhibitory activity of Antarctic krill protein hydrolysates Acidic protease, neutral protease, trypsin, pepsin and papain were used to enzymolyze Antarctic krill protein. The temperature and pH of the enzymolysis were all at the optimal temperature and pH of each protease (Table 3). The other conditions were the same as those of alkaline protease. After the enzymolysis was completed, the effects of different proteases on the hydrolysis degree and pancreatic lipase inhibitory activity of Antarctic krill hydrolysates were determined. The results are shown in Figure 1 , Figure 2 shown.

[0036] Table 3 Optimal temperature and pH of different proteases

[0037] The degree of protein hydrolysis is one of the important indicators for evaluating the biological activity of enzymatic hydrolysis products. Different types of proteases hydrolyze proteins to different degrees at different times. A good hydrolysis effect can release more biologically active groups. Figure 1 It can be seen that the degree of hydrolysis of Antarctic krill protein by alkaline protease is 38.64%±1.15, which is significantly higher than the hydrolysis products of the other five proteases (P<0.05). This is because under the condition of sufficient substrate, alkaline protease has more cleavage sites, good heat resistance and hydrolysis performance, and the protein is more easily hydrolyzed into small molecular peptides.

[0038] Part of the dietary fat in the human body can be hydrolyzed by pancreatic lipase. When the activity of pancreatic lipase is inhibited by small molecule peptides, dietary fat cannot be broken down into short-chain fatty acids, which results in the body being unable to absorb fat. Therefore, the inhibitory activity of Antarctic krill enzymatic hydrolysate on pancreatic lipase was selected as the main indicator for evaluating its lipid-lowering and weight-loss activity. Figure 2 It can be seen that compared with the other five proteases, the enzymatic hydrolysis products of alkaline protease have a stronger inhibitory effect on pancreatic lipase, which is 34.20%±1.28. Alkaline protease is a serine protease, and the active center of this type of protease contains serine residues. Using alkaline protease digestion is more conducive to improving lipid-lowering and weight-loss activity, so alkaline protease is selected as the best hydrolase.

[0039] The amino acid composition of the Antarctic krill protease hydrolysate was analyzed using an amino acid analyzer, and the steps are as follows: The freeze-dried samples were treated with 6 mol / L HCl at 110°C for 24 h under nitrogen atmosphere. The digested mixture was transferred to a centrifuge tube and dried under reduced pressure at 50°C. The dried samples were dissolved in distilled water twice. Finally, the dried samples were dissolved in sodium citrate buffer (pH 2.2) and filtered through a 0.22 µm filter before testing. The results are shown in Table 4.

[0040] Table 4 Amino acid composition and content of alkaline protease hydrolysate

[0041] The efficacy of bioactive peptides is closely related to the composition and content of their amino acids and their arrangement order on the peptide chain. As shown in Table 4, the hydrophobic amino acids such as valine, leucine, phenylalanine, and isoleucine are relatively rich in the alkaline protease hydrolysate, with contents of 3.05g / 100g, 3.03g / 100g, 2.57g / 100g, and 2.16g / 100g, respectively. These amino acids help to improve the biological activity of small molecule peptides and have potential lipid-lowering and weight-loss activities, which is consistent with the structure and functional characteristics of weight-loss peptides. At the same time, the essential amino acids such as lysine, tryptophan, methionine, and threonine in the Antarctic krill protease hydrolysate are also very rich and have high nutritional value.

[0042] (4) The hydrolyzed products of Antarctic krill alkaline protease were fractionated into different molecular weights using 10KDa ultrafiltration centrifuge tubes and 3KDa ultrafiltration centrifuge tubes. The ultrafiltration parameters were set to 4000×g, 25min until all the liquid passed through the membrane. The components were collected: peptides >10KDa, 3~10KDa, and <3KDa. All components were freeze-dried and stored in sealed bottles at -20℃. The pancreatic lipase inhibitory activity and α-amylase inhibitory activity of the components with different molecular weights were measured, and their weight loss effects were analyzed.

[0043] Ultrafiltration centrifuge tubes can efficiently and quickly concentrate small molecules such as peptides, nucleic acids, antigens, antibodies, etc., and have advantages including high flow rate, high throughput, high concentration multiple protein adsorption characteristics, and high recovery rate. The soluble protein hydrolysate produced by alkaline protease is ultrafiltered using ultrafiltration centrifuge tubes and divided into three parts: MW>10KDa, MW between 3~10KDa, and MW<3KDa. The separation and enrichment of small molecule peptides is achieved through ultrafiltration separation. Figure 3 It can be seen that the inhibition rate of the component with MW < 3kDa on pancreatic lipase (56.99% ± 2.17) was significantly higher (P < 0.05) than that of the components with MW > 10KDa and MW between 3 and 10KDa (30.88% ± 2.91 and 47.37% ± 4.93), which can effectively inhibit the activity of pancreatic lipase. This may be because the macromolecular substances are transformed into small molecular active fragments, and the content of short peptides in the components with smaller molecular weight is higher, and short peptides are more likely to exert better biological activity.

[0044] α-amylase can break down starch, and amylase inhibitors reduce carbohydrate absorption by preventing starch from breaking down into glucose in the small intestine. Therefore, the inhibitory activity of Antarctic krill enzymatic hydrolysate on α-amylase was selected as another indicator to evaluate its lipid-lowering and weight-loss activity. Figure 4It can be seen that the component with MW < 3kDa has the most obvious lipid-lowering and weight-loss activity, and its α-amylase inhibitory activity is 19.03% ± 0.76. Most of the short peptides with smaller molecular weight intercepted by the protease hydrolysate. In summary, the component with MW < 3kDa can significantly (P < 0.05) inhibit the activity of pancreatic lipase and α-amylase, and has the potential of lipid-lowering and weight-loss functional characteristics, so it is selected for further separation and purification.

[0045] (5) The ultrafiltration fraction with MW < 3 kDa was further separated and purified using a Sephadex G-25 gel filtration column (2.0*40 cm), first equilibrated with ultrapure water, and then eluted with ultrapure water at a flow rate of 0.3 mL / min. Each part of the eluate was monitored at 280 nm, and the resulting peaks were collected.

[0046] The enzymatic fraction with MW < 3KDa was further separated and purified on a Sephadex G-25 gel filtration column. Figure 5 As shown, the distilled water elution component shows three peaks, named F1, F2, and F3, and the eluted components are collected according to the peak elution time. The lower the molecular weight, the longer the retention time of the separated peptide. Therefore, it can be inferred that F1 has the largest molecular weight, F2 is the second to be separated in the chromatographic column, and its molecular weight is in the middle, and F3 has the smallest molecular weight.

[0047] The weight loss effects of the three different elution fractions were evaluated. Figure 6 and Figure 7 shown.

[0048] Depend on Figure 6 It can be seen that the F2 component separated by Sephadex G-25 gel filtration column has the highest pancreatic lipase inhibitory activity of 64.11±0.36%, which is 1.87 times that of the enzymatic hydrolysis product before separation, and there are significant differences between it and other peaks (P<0.05). The F1 component and F3 component are 36.10±0.48% and 52.14±2.05%, respectively.

[0049] Depend on Figure 7 It can be seen that the α-amylase inhibitory activity of the F2 component separated by Sephadex G-25 gel filtration column was significantly higher than that of the enzymatic hydrolysate before separation and the F1 and F3 components (P<0.05), reaching 33.51%±0.57. This is mainly attributed to the fact that in natural protein molecules, the hydrophobic groups are wrapped in the folded structure area inside the protein molecules, and when the protein is hydrolyzed, the hydrophobic groups inside are exposed, which in turn increases the surface hydrophobicity. As the separation and purification proceed, these exposed groups will be further concentrated into smaller peptide segments.

[0050] (6) The F2 fraction with the best weight loss effect after gel filtration chromatography was selected for LC-MS / MS analysis. After centrifugation and drying, the enzymatic peptide samples were redissolved in Nano-LC mobile phase A (0.1% formic acid / water) and bottled for online LC-MS / MS analysis. The dissolved samples were loaded onto a nanoViper C18 pre-column (3μm, 100Å) and washed and desalted. The liquid phase was an EasynLC 1200 nanoliter liquid phase system (ThermoFisher, USA). The samples were desalted and retained on the pre-column and then separated by an analytical column. The analytical column specifications were a C18 reverse phase chromatography column (Acclaim PepMap RSLC, 75μm×25cm C18-2μm 100Å). The gradient used in the experiment increased the mobile phase B (80% acetonitrile, 0.1% formic acid) from 5% to 38% within 30 minutes. The mass spectrometer used a ThermoFisher QExactive system (ThermoFisher, USA) combined with a nanospray Nano Flex ion source (ThermoFisher, USA), with a spray voltage of 1.9 kV and an ion transfer tube heating temperature of 275 °C. The mass spectrometer scan mode was in the information-dependent acquisition mode (DDA, Data Dependent Analysis), with a primary mass spectrometer scan resolution of 70000, a scan range of 350-2000 m / z, and a maximum injection time of 100 ms. A maximum of 20 secondary spectra with charges of 2+ to 5+ were collected in each DDA cycle, and the maximum injection time of the secondary mass spectrometer ions was 50 ms. The collision cell energy (high-energy collision-induced dissociation, HCD) was set to 28 eV, applicable to all precursor ions, and the dynamic exclusion was set to 25 seconds.

[0051] Table 5 Amino acid sequence of Antarctic krill anti-obesity peptide identified by LC-MS / MS

[0052] The peptide mixture F2 was analyzed using the LC-MS / MS high-resolution mass spectrometry platform to detect the mass-to-charge ratio (m / z) of the analyte and compare it with the theoretical value, thereby accurately identifying the target analyte, which plays a key role in the amino acid sequence identification of the peptide. The information of the two peptides identified by subcomponent F2 is shown in Table 5. The amino acid sequence was identified as Gln-Leu-Gly-Ile-Lys (QLGIK) and Asn-Thr-Asp-Lys-Gln-Val-Thr (NTDKQVT), with 5 and 7 amino acids, respectively.

[0053] The secondary mass spectra of Antarctic krill weight loss peptides QLGIK and NTDKQVT are as follows Figure 8 , Fig. 9As shown, a clear mass spectrum was obtained from the peptide ion, and some b- and y-ions derived from the peptide ion were also shown.

[0054] The two peptides QLGIK and NTDKQVT (purity>95%) synthesized by biosynthesis and analyzed by LC-MS / MS have the following primary mass spectra: Fig.10 , Fig.11 As shown, the precise molecular weights determined were 558.4 and 805.6, respectively. Comparing them with the previous theoretical values, the molecular weights were basically consistent, verifying the accuracy of the synthetic peptides.

[0055] Example 3 A bioactive peptide preparation with weight loss effect, wherein the active ingredient is at least one of the bioactive peptides with amino acid sequences represented by QLGIK and NTDKQVT.

[0056] Accurately weigh 2 mg of QLGIK (QK) and NTDKQVT (NT) and dissolve them in 4 mL of deionized water, and dissolve them in each other to prepare the composite peptide QLGIK + NTDKQVT (QK + NT). The concentration of each peptide is 0.5 mg / mL. The lipid-lowering and weight-loss activity was further verified by measuring the pancreatic lipase inhibitory activity and α-amylase inhibitory activity. The results are as follows Fig.12 , Fig.13 As shown. The three peptides QK, NT, and QK+NT all showed high lipid-lowering and weight-loss activities, with the inhibitory activities of pancreatic lipase being 74.08%±1.40, 65.52%±1.98, and 69.78%±0.73, respectively, and the inhibitory activities of α-amylase being 43.47%±1.25, 36.83%±0.74, and 40.18%±0.72, respectively. Among them, the pancreatic lipase inhibitory activity and α-amylase inhibitory activity of QK were significantly higher than those of NT and QK+NT (P<0.05), which may be because the molecular weights of the two peptides are different, and the molecular weight is an important factor affecting the biological activity of polypeptides. At the same concentration, the smaller the molecular weight, the stronger the overall biological activity of the peptide. QK has the lowest molecular weight, which gives it the strongest lipid-lowering and weight-loss activity.

[0057] The above results show that both QLGIK and NTDKQVT peptides have the appropriate number of amino acids, structure and peptide length, which meet the characteristics of natural weight loss peptides, are conducive to the development and utilization of bioactive peptides and weight loss products, and have great potential to be used as functional ingredients in the fields of health foods and cosmetic medicine.

[0058] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. A bioactive peptide with weight loss effect, characterized in that: The amino acid sequence of the bioactive peptide with weight loss effect is at least one of QLGIK and NTDKQVT.

2. Use of the bioactive peptide with weight loss effect as claimed in claim 1 in the preparation of a product with weight loss effect.

3. The use of the bioactive peptide with weight loss effect according to claim 2 in the preparation of a product with weight loss effect, characterized in that: The product is food, medicine or health product.

4. The use of the bioactive peptide with weight loss effect according to claim 3 in preparing a product with weight loss effect, characterized in that: The product further comprises excipients acceptable to food, medicine or health care products.

5. A bioactive peptide preparation having weight loss effect, characterized in that: The active ingredient of the preparation is at least one of the bioactive peptides shown in QLGIK and NTDKQVT.

6. The bioactive peptide preparation with weight loss effect according to claim 5, characterized in that: The concentration of the active ingredient is 0.5 mg / mL.

7. The bioactive peptide preparation with weight loss effect according to claim 5 or 6, characterized in that: The weight loss effect is that it has the activity of inhibiting pancreatic lipase and α-amylase.

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