Bioactive peptides, formulations, and applications having anti-obesity effects

Abstract

This invention provides bioactive peptides, formulations, and applications that have anti-obesity effects. [Solution] The amino acid sequence of the bioactive peptide having an anti-obesity effect of the present invention is at least one of QLGIK and NTDKQVT. An application of the bioactive peptide in the preparation of a product having an anti-obesity effect is provided, the product being a food, a pharmaceutical or a health functional food.

Description

[Technical Field]

[0001] The present invention relates to the technical field of bioactive peptides, and specifically to a bioactive peptide having an anti-obesity effect, a preparation and the use thereof. [Background Art]

[0002] Fat components in food are mainly triglycerides. When food is ingested, the water-insoluble fat is first emulsified into chylomicrons in the stomach, and then hydrolyzed by water-soluble lipase in the duodenum. Subsequently, hydrolysis by lipase produces fatty acids and monoglycerides, which are converted into soluble mixed micelles under the action of bile acid micelles, which are then absorbed in the digestive tract and resynthesized into fat in vivo. Excessive intake of high-fat food ultimately leads to accumulation of body fat, that is, obesity. In order to effectively prevent, control and treat obesity and reduce the adverse effects of obesity on the human body, many technical approaches have been researched and attempted. Among them, methods for controlling and treating obesity include physical methods and chemical methods. Physical methods refer to fat reduction through diet control, exercise and liposuction, while chemical methods refer to achieving the purpose of fat reduction through the chemical action of certain drugs and health functional foods. Among these techniques, taking anti-obesity drugs is one of the effective and convenient methods for preventing or adjuvant treating obesity.

[0003] According to studies up to the present, the discovered functional food ingredients with lipid-lowering and anti-obesity effects include substances such as alkaloids, saponins, L-carnitine, enzymes and phenolphthalein. Anti-obesity drugs composed of these active substances often achieve the purposes of weight control and anti-obesity by reducing appetite through affecting gastrointestinal reactions and regulating the nervous system, or inhibiting the absorption of glucose, protein and lipid by the gastrointestinal tract. However, the side effects of such drugs are often proportional to the dosage, that is, the larger the dosage, the greater the side effects. They can cause insomnia, fatigue, diarrhea, vomiting, elevated blood pressure, and may even cause tachycardia, arrhythmia and heart failure. Side effects and safety concerns of anti-obesity drugs are important factors limiting their application in the food industry.

[0004] Bioactive peptides generally have a molecular weight of less than 6000 Da, contain at least two amino acids, possess excellent functionality and unique activity, and can regulate specific physiological functions and life activities in living organisms. They play important roles in various biological processes, including hormone regulation, immune responses, and cell signaling. Naturally occurring bioactive peptides with anti-obesity effects isolated from natural substances, such as functional peptides that inhibit pancreatic lipase and α-amylase activity, and active peptides that regulate appetite hormones and influence the proliferation and differentiation of preadipocytes to reduce fat content, are safe and side-effect-free functional ingredients with great potential as alternatives to conventional anti-obesity drugs. [Overview of the project]

[0005] In view of the problems existing in the prior art, the object of the present invention is to provide a bioactive peptide, a formulation, and its applications that have an anti-obesity effect.

[0006] To achieve the above objective, the present invention employs the following technical solutions: A bioactive peptide having an anti-obesity effect, wherein the amino acid sequence of the bioactive peptide having an anti-obesity effect is at least one of QLGIK and NTDKQVT.

[0007] This involves the application of the above-mentioned bioactive peptides with anti-obesity effects in the preparation of products with anti-obesity effects.

[0008] Based on the above technical solution, the product is a food, a pharmaceutical, or a health functional food.

[0009] Based on the above technical solution, the product further contains additives that are permissible in terms of food, pharmaceutical, or health functional foods.

[0010] A bioactive peptide preparation having an anti-obesity effect, wherein the active ingredient of the preparation is a bioactive peptide represented by at least one of QLGIK and NTDKQVT.

[0011] Based on the above technical solution, the concentration of the active ingredient in the bioactive peptide preparation having the anti-obesity effect is 0.5 mg / mL.

[0012] Based on the above technical solution, the aforementioned anti-obesity effect is due to the presence of pancreatic lipase and α-amylase inhibitory activity.

[0013] The technical solution of the present invention has the following advantages.

[0014] This invention uses defatted krill (Euphausia superba) protein as a raw material to isolate bioactive peptides with anti-obesity effects using enzymatic hydrolysis, ultrafiltration, gel filtration chromatography, and liquid chromatography separation techniques. The components and sequences of these peptides were initially identified by liquid chromatography-mass spectrometry. Based on the identified peptide sequences, chemical synthesis was performed to obtain two bioactive peptides with anti-obesity effects, QLGIK and NTDKQVT. Detection results showed that both peptides and their complex peptides exhibited good pancreatic lipase and α-amylase inhibitory activity, indicating promising applications in the preparation of anti-obesity products. This provides a foundation for promoting high-value-added utilization of krill protein and the research, development, and application of functionally active peptides.

[0015] Conventional anti-obesity drugs, such as orlistat, sibutramine, Qsymia, and phenolphthalein, can cause disruption of the endocrine system, malnutrition, and increased neuronal excitability. Long-term use can affect the normal secretory function of the gastrointestinal tract and pose potential health risks. In contrast, the bioactive peptide isolated by the present invention has a good anti-obesity effect, its raw material is natural, non-toxic krill protein, it is green and safe, does not involve the introduction of organic solvents in the preparation process, has no side effects, is easy to handle, requires little equipment, and has the potential to be used as a novel anti-obesity product in the field of functional foods. [Brief explanation of the drawing]

[0016] [Figure 1] This figure shows the effect of different proteases on the hydrolysis of krill proteins (where there are significant differences between data shown in different lowercase letters, P<0.05). [Figure 2] This figure shows the effect of different proteases on the pancreatic lipase inhibitory activity of krill enzyme degradation products (where there are significant differences between data shown in different lowercase letters, P<0.05). [Figure 3] This figure shows the inhibitory activity on pancreatic lipase by components of different molecular weights after ultrafiltration (where there are significant differences between data shown in different lowercase letters, P<0.05). [Figure 4] This figure shows the inhibitory activity on α-amylase by components of different molecular weights after ultrafiltration (where there are significant differences between data shown in different lowercase letters, P<0.05). [Figure 5] This figure shows the components after separation and purification by gel filtration chromatography. [Figure 6] This figure shows the inhibitory activity of each component on pancreatic lipase after gel filtration chromatography (where there are significant differences between data shown in different lowercase letters, P<0.05). [Figure 7] This figure shows the inhibitory activity of each component on α-amylase after gel filtration chromatography (where there are significant differences between data shown in different lowercase letters, P<0.05). [Figure 8] This is the second-order mass spectrum of the krill peptide QLGIK. [Figure 9] This is the second-order mass spectrum of the krill peptide NTDKQVT. [Figure 10] This is the primary mass spectrum of the biologically synthesized peptide QLGIK. [Figure 11] This is the primary mass spectrum of the biologically synthesized peptide NTDKQVT. [Figure 12] This figure shows the inhibitory activity of various biosynthetic peptides on pancreatic lipase (where there are significant differences between data shown in different lowercase letters, P<0.05). [Figure 13]It is a graph showing the inhibitory activity of each peptide after biological synthesis on α-amylase (here, there is a significant difference between data indicated by different lowercase letters, P<0.05). Mode for Carrying Out the Invention

[0017] Unless otherwise specified, the terms used in the present invention generally have the meanings commonly understood by those skilled in the art. Hereinafter, the present invention will be described in further detail with reference to specific examples and data. The following examples are illustrative of the present invention and are not intended to limit the scope of the present invention in any way.

[0018] Unless otherwise specified, all experimental methods in the following examples are known methods, and are carried out in accordance with techniques or conditions described in literatures in the art or product instructions. Unless otherwise specified, all test materials, solvents, chemicals and the like used in the following examples are commercially available through regular distribution channels.

[0019] In the following examples, 1. Method for measuring the degree of hydrolysis of krill protein: 80 mg of OPA is dissolved and mixed in 2 mL of absolute ethanol, 200 µL of β-mercaptoethanol, 5 mL of 10% (w / v) SDS and 92.8 mL of 0.1 mol / L sodium tetraborate to prepare 100 mL of OPA reagent solution. 40 µL of krill enzymatic hydrolysate is mixed with 4 mL of the OPA reagent, incubated at room temperature for 2 min, and the absorbance at a wavelength of 340 nm is measured. Krill protein is added to 6 mol / L HCl, reacted at 115°C for 24 h, the number of free amino groups is measured using a serine standard curve, which is taken as the number of free amino groups generated by complete hydrolysis of krill protein.

[0020] The degree of hydrolysis of krill protein is calculated according to the following formula: JPEG2026142530000002.jpg1155

[0021] In the formula: (NH2) trepresents the number of free amino groups in the enzymatic degradation product at time t, and (NH2) t0 (NH2) represents the number of free amino groups that do not undergo enzymatic hydrolysis. T This represents the number of free amino groups after complete hydrolysis.

[0022] 2. Method for measuring pancreatic lipase inhibitory activity: Using p-nitrophenyl butyrate (0.005 mol / L) as a substrate, krill enzyme degradation products and pancreatic lipase (1.25 mg / mL) were added to PBS (0.01 mol / L, pH 7.4). The mixture was dispensed into a 96-well plate, the volume of the reaction mixture was adjusted to 150 μL with PBS, and incubated at 37°C for 30 minutes. The absorbance at a wavelength of 405 nm was then measured using a multimode microplate reader. The components of the reaction system are shown in Table 1.

[0023] Table 1 Composition of each reaction system for measuring pancreatic lipase inhibitory activity JPEG2026142530000003.jpg46131

[0024] Calculation of results: The inhibitory effect of krill enzyme degradation products on lipase activity was calculated according to the following formula: JPEG2026142530000004.jpg1039

[0025] Here, I: inhibition rate of pancreatic lipase by krill enzyme degradation products, A: blank tube, a: blank control tube, B: inhibited tube, b: background control tube, " / " indicates no additive.

[0026] 3. Method for measuring α-amylase inhibitory activity α-amylase activity is measured by spectrophotometric analysis using soluble starch as a substrate and 3,5-dinitrosalicylic acid (DNS) as a colorimeter. 0.25 mL of 4 units / mL α-amylase and 0.25 mL of krill enzyme degradation product are each added to 0.5 mL of pH 6.9 0.2 mol / L PBS and incubated at 37°C for 10 min. Then, 0.5 mL of 1% soluble starch solution is added and the mixture is reacted precisely for 5 min. Finally, 1 mL of DNS reagent is added, the mixture is boiled for 10 min, rapidly cooled under running water, diluted five-fold, and the absorbance at a wavelength of 540 nm is measured. The components of the reaction system are shown in Table 2.

[0027] Table 2 System Compositions for α-Amylase Activity Measurement JPEG2026142530000005.jpg52143

[0028] Calculation of results: The inhibitory effect of krill enzyme degradation products on α-amylase activity was calculated according to the following formula: JPEG2026142530000006.jpg1039

[0029] Here, I: inhibition rate of α-amylase by krill enzyme degradation products, A: blank tube, a: blank control tube, B: inhibitory tube, b: background control tube, " / " indicates no additive.

[0030] The krill used in the examples were purchased from Qingdao Antarctic Weikang Biotechnology Co., Ltd. (Qingdao, China).

[0031] Example 1 A bioactive peptide having an anti-obesity effect, wherein the amino acid sequence of the bioactive peptide is shown in SEQ ID NO:1 or SEQ ID NO:2.

[0032] SEQ ID NO:1:QLGIK, SEQ ID NO:2:NTDKQVT.

[0033] Example 2 A method for extracting bioactive peptides with anti-obesity effects from krill includes the following steps: (1) Weigh 100g of krill meat with the heads and shells removed, wash it, place it in a beaker, and homogenize it by adding deionized water (4°C) with a liquid-to-solid ratio of 3.17 mL / g. Then, adjust the pH to 11.38 with 2 mol / L sodium hydroxide, let it stand for 0.5 hours, and then centrifuge for 10 minutes under conditions of 4°C and 10000 g to obtain the supernatant. Repeat the entire extraction process three times. Finally, adjust the pH of the collected supernatant to 4.5 with 2 mol / L phosphoric acid, let it stand for 1.0 hour, and then centrifuge for 10 minutes under conditions of 4°C and 10000 g to collect the precipitate, freeze-dry it at -80°C, and store it as krill protein.

[0034] (2) Weigh 5 g of the krill protein extracted in step (1), add acetone solution in a ratio of 1:4 (w:v), stir in a constant temperature magnetic stirrer for 3 hours, then let stand for 0.5 hours until the liquid becomes clear. The red liquid on top is krill oil, so pour it out, add acetone again, stir for 2 hours, then let stand for 0.5 hours, pour out the red liquid on top, and repeat the above procedure until the liquid on top becomes colorless, and recover the defatted krill protein in a fume hood.

[0035] (3) Weigh the defatted krill protein prepared in step (2), dissolve it in deionized water at a ratio of 2% (w / v), add alkaline protease to the solution, adding 3000 U of alkaline protease per gram of krill protein, stir uniformly at low speed, adjust the pH to 9.5 and the temperature to 55°C, and carry out the enzymatic reaction in a constant temperature incubator for 4 hours. After enzymatic decomposition, heat the reaction solution in boiling water for 15 minutes to inactivate the protease and stop the reaction, immediately cool to 4.0°C in ice water, centrifuge at 12000 g for 15 minutes, retain the supernatant (called AKPH), freeze-dry it to obtain the enzymatic decomposition product of krill protein.

[0036] Effects of different proteases on the hydrolysis of krill protein enzyme degradation products and their inhibitory activity on pancreatic lipase Krill proteins were enzymatically digested using acidic proteases, neutral proteases, trypsin, pepsin, and papain, respectively. The enzymatic digestion temperature and pH were determined according to the optimal temperature and pH for each protease (Table 3), while other conditions were the same as for alkaline proteases. After enzymatic digestion, the effects of different proteases on the hydrolysis degree of the krill enzymatic digestion product and its pancreatic lipase inhibitory activity were measured. The results are shown in Figures 1 and 2.

[0037] Table 3 Optimal temperature and pH for different proteases JPEG2026142530000007.jpg76147

[0038] Protein solubility is one of the important indicators for evaluating the biological activity of enzymatic degradation products. Different types of proteases exhibit different levels of protein solubility over different time periods, and better solubility releases more biologically active groups. As can be seen in Figure 1, the solubility of krill protein by alkaline proteases was 38.64% ± 1.15, which was significantly higher than the enzymatic degradation products of the other five types of proteases (P<0.05). This is because, under conditions where the substrate is sufficient, alkaline proteases have more enzymatic cleavage sites, superior heat resistance and hydrolysis performance, and proteins are more easily hydrolyzed into low-molecular-weight peptides.

[0039] A portion of human dietary fat is hydrolyzed by pancreatic lipase. When pancreatic lipase activity is inhibited by low-molecular-weight peptides, dietary fat is not broken down into short-chain fatty acids, and as a result, the body is unable to absorb fat. Therefore, the inhibitory activity of krill enzyme hydrolysis products on pancreatic lipase was selected as the main indicator of their lipid-lowering and anti-obesity activity. As can be seen from Figure 2, compared to the other five types of proteases, the enzyme hydrolysis product obtained from alkaline proteases had a stronger inhibitory effect on pancreatic lipase, at 34.20% ± 1.28. Alkaline proteases are serine proteases, and the active site of such proteases contains serine residues. Digestion by alkaline proteases is advantageous for improving lipid-lowering and anti-obesity activity, so alkaline proteases were selected as the optimal hydrolytic enzyme.

[0040] The amino acid composition of the enzymatic degradation products of krill protein was analyzed using an amino acid analyzer, and the steps were as follows: The freeze-dried samples were treated with 6 mol / L HCl under a nitrogen atmosphere at 110°C for 24 hours. The digested mixture was transferred to a centrifuge tube and dried under reduced pressure at 50°C. The dried samples were dissolved twice with distilled water. Finally, the dried samples were dissolved in sodium citrate buffer (pH 2.2), filtered through a 0.22 μm filter, and injected into the instrument for analysis. The results are shown in Table 4.

[0041] Table 4 Amino acid composition and content of alkaline protease enzyme degradation products JPEG2026142530000008.jpg102141

[0042] The effects of bioactive peptides are closely related to their amino acid composition, content, and sequence on the peptide chain. As can be seen from Table 4, alkaline protease enzyme degradation products are relatively rich in hydrophobic amino acids such as valine, leucine, phenylalanine, and isoleucine, with content of 3.05g / 100g, 3.03g / 100g, 2.57g / 100g, and 2.16g / 100g, respectively. These amino acids are advantageous for improving the bioactivity of low molecular weight peptides, possess potential lipid-lowering and anti-obesity activity, and are consistent with the structural and functional characteristics of anti-obesity peptides. At the same time, krill protein enzyme degradation products are also very rich in essential amino acids such as lysine, tryptophan, methionine, and threonine, making them highly nutritionally valuable.

[0043] (4) The krill alkaline protease enzyme degradation products were fractionated into different molecular weights using 10 kDa ultrafiltration centrifuge tubes and 3 kDa ultrafiltration centrifuge tubes. The ultrafiltration parameters were set to 4000 × g and 25 min, and the process was carried out until all the liquid had passed through the membrane. The recovered components were peptides of >10 kDa, 3-10 kDa, and <3 kDa. All components were freeze-dried and stored in sealed bottles at -20°C. The pancreatic lipase inhibitory activity and α-amylase inhibitory activity of the different molecular weight components were measured, and their anti-obesity effects were further analyzed.

[0044] Ultrafiltration centrifuge tubes can efficiently and rapidly concentrate low molecular weight substances such as peptides, nucleic acids, antigens, and antibodies, and have advantages such as high flow rate, high throughput, high concentration ratio protein adsorption characteristics, and high recovery rate. Soluble protein hydrolysates produced by alkaline proteases were ultrafiltered using ultrafiltration centrifuge tubes and separated into three parts: MW>10kDa, MW3~10kDa, and MW<3kDa. Separation and concentration of low molecular weight peptides were achieved by ultrafiltration separation. As can be seen from Figure 3, the inhibition rate of pancreatic lipase by the MW<3kDa component (56.99%±2.17) was significantly higher than that of the two components MW>10kDa and MW3~10kDa (30.88%±2.91, 47.37%±4.93) (P<0.05), indicating good inhibition of pancreatic lipase activity. This is thought to be because high molecular weight substances are converted into low molecular weight active fragments, and components with smaller molecular weights have a higher content of short-chain peptides, which then more easily exhibit superior biological activity.

[0045] α-amylase can break down starch, and amylase inhibitors inhibit the breakdown of starch into glucose in the small intestine, thereby reducing carbohydrate absorption. Therefore, the inhibitory activity of krill enzyme degradation products on α-amylase was selected as another indicator to evaluate their lipid-lowering and anti-obesity activity. As can be seen from Figure 4, the lipid-lowering and anti-obesity activity of the MW < 3 kDa component was the most pronounced, with an α-amylase inhibitory activity of 19.03% ± 0.76, and it contained many short-chain peptides with small molecular weights that were retained in the membrane in the proteolytic hydrolysis solution. In summary, the MW < 3 kDa component significantly inhibited the activity of pancreatic lipase and α-amylase (P < 0.05) and has the potential for lipid-lowering and anti-obesity functional properties, so it was selected and further isolated and purified.

[0046] (5) Components with MW < 3 kDa after ultrafiltration were collected and further separated and purified using a Sephadex G-25 gel filtration column (2.0 * 40 cm). The solution was 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.

[0047] Enzymatically degraded components with MW < 3 kDa were further separated and purified on a Sephadex G-25 gel filtration column. The elution results are shown in Figure 5, where the distilled water eluted components showed a total of three peaks, named F1, F2, and F3, respectively. The eluted components were collected according to their peak appearance time. Since lower molecular weights correspond to longer retention times of separated peptides, it is presumed that F1 had the largest molecular weight, F2 was separated third in the column with an intermediate molecular weight, and F3 had the smallest molecular weight.

[0048] The anti-obesity effects of the three different eluting components described above were evaluated. The results are shown in Figures 6 and 7.

[0049] As can be seen in Figure 6, the F2 component separated by Sephadex G-25 gel filtration column showed the highest pancreatic lipase inhibitory activity at 64.11±0.36%, which was 1.87 times that of the enzyme degradation product before separation and showed a significant difference from the other peaks (P<0.05). The F1 and F3 components were 36.10±0.48% and 52.14±2.05%, respectively.

[0050] As can be seen in Figure 7, the α-amylase inhibitory activity of component F2, separated by Sephadex G-25 gel filtration column, was significantly higher (P<0.05) than that of the enzymatically degraded product before separation and components F1 and F3, reaching 33.51%±0.57. This is mainly because, in native protein molecules, the hydrophobic groups are embedded in the folded structural regions within the protein molecule, but when the protein is hydrolyzed, these internal hydrophobic groups are exposed, thereby increasing its surface hydrophobicity. As separation and purification progress, these exposed groups are concentrated in smaller peptides.

[0051] (6) After gel filtration chromatography, the F2 component with the best anti-obesity effect was collected and analyzed by LC-MS / MS. The enzyme-cleaved polypeptide sample was centrifuged and dried, then redissolved in Nano-LC mobile phase A (0.1% formic acid / water), packed into a vial, injected, and analyzed online by LC-MS / MS. The redissolved sample was then placed in a nanoViper C18 pre-column (3 μm, 100 The sample was injected into JPEG2026142530000009.jpg43) and washed and desalted. Using a Liquid Easy nLC 1200 nanoliter liquid system (ThermoFisher, USA), the sample was desalted and held on a pre-column before being separated on an analytical column. The analytical column specifications were C18 reversed-phase chromatography column (Acclaim PepMap RSLC, 75 μm × 25 cm C18-2 μm 100). The image (JPEG2026142530000010.jpg43) shows that the gradient used in the experiment increased the mobile phase B (80% acetonitrile, 0.1% formic acid) from 5% to 38% within 30 min. The mass spectrometer used was a ThermoFisher Q Exactive system (ThermoFisher, USA) combined with a nanoliter spray Nano Flex ion source (ThermoFisher, USA). The spray voltage was 1.9 kV, and the heating temperature of the ion transfer tube was 275°C. The mass spectrometry scanning method was Data Dependent Analysis (DDA), with a primary mass spectrometry scanning resolution of 70000, a scanning range of 350-2000 m / z, and a maximum injection time of 100 ms. Up to 20 secondary spectra from charge 2+ to 5+ were acquired in each DDA cycle, and the maximum injection time for secondary mass spectrometry ions was 50 ms. The collision chamber energy (high-energy collision-induced dissociation, HCD) was set to 28 eV and applied to all precursor ions, and the dynamic exclusion time was set to 25 seconds.

[0052] Table 5. Identification of the amino acid sequence of krill anti-obesity peptide by LC-MS / MS. JPEG2026142530000011.jpg32137

[0053] Using a high-resolution LC-MS / MS liquid chromatography-tandem mass spectrometry platform, peptide mixture F2 was analyzed, and the mass-to-charge ratio (m / z) of the analyte was detected and compared with a theoretical value. This allowed for accurate identification of the target analyte and played a crucial role in the identification of the polypeptide amino acid sequence. Table 5 shows the information of the two peptides identified from subcomponent F2. The amino acid sequences were identified as Gln-Leu-Gly-Ile-Lys (QLGIK) and Asn-Thr-Asp-Lys-Gln-Val-Thr (NTDKQVT), with 5 and 7 amino acids, respectively. The secondary mass spectra of the krill anti-obesity peptides QLGIK and NTDKQVT are shown in Figures 8 and 9, where clear mass spectra are obtained from the peptide ions, and several β- and γ- ions derived from the peptide ions are also shown.

[0054] Two peptides, QLGIK and NTDKQVT (purity >95%), obtained by LC-MS / MS analysis using a biological synthesis method, were synthesized. Their primary mass spectra are shown in Figures 10 and 11, and the measured precise molecular weights were 558.4 and 805.6, respectively. Compared with previous theoretical values, the molecular weights were in essentially agreement, confirming the accuracy of the synthesized peptides.

[0055] Example 3 A bioactive peptide preparation having an anti-obesity effect, wherein the active ingredient is at least one of the bioactive peptides having the amino acid sequence represented by QLGIK and NTDKQVT.

[0056] QLGIK (QK) and NTDKQVT (NT) were accurately weighed at 2 mg each, dissolved in 4 mL of deionized water, and mixed to prepare the complex peptide QLGIK+NTDKQVT (QK+NT), with the concentration of each peptide set to 0.5 mg / mL. The lipid-lowering and anti-obesity activities were further verified by measuring pancreatic lipase inhibitory activity and α-amylase inhibitory activity, and the results are shown in Figures 12 and 13. All three peptides, QK, NT, and QK+NT, showed high lipid-lowering and anti-obesity activity. The pancreatic lipase inhibitory activities were 74.08%±1.40, 65.52%±1.98, and 69.78%±0.73, respectively, and the α-amylase inhibitory activities were 43.47%±1.25, 36.83%±0.74, and 40.18%±0.72, respectively. Here, the pancreatic lipase inhibitory activity and α-amylase inhibitory activity of QK were significantly higher than that of NT and QK+NT (P<0.05). This is thought to be because the molecular weights of the two peptides differ, and molecular weight is an important factor influencing polypeptide biological activity. At the same concentration, peptides with smaller molecular weights exhibit stronger overall biological activity, and QK has the lowest molecular weight, which is thought to be the reason why it possesses the strongest lipid-lowering and anti-obesity activity.

[0057] The results above indicate that both peptides, QLGIK and NTDKQVT, possess appropriate amino acid counts, structures, and peptide lengths, matching the characteristics of natural anti-obesity peptides. This makes them advantageous for the development and use of bioactive peptides and anti-obesity products, and demonstrates great potential for use as functional ingredients in health functional foods and cosmetic medicine.

[0058] Although preferred embodiments of the present invention have been described above, this does not limit the present invention in any way, and those skilled in the art can create equivalent embodiments by making equivalent changes or modifications based on the disclosed technical content. Any simple modifications, equivalent changes, and modifications made to the embodiments based on the technical substance of the present invention, as long as they do not deviate from the content of the technical solution of the present invention, shall all be within the scope of protection of the technical solution of the present invention.

Claims

1. A bioactive peptide having an anti-obesity effect, characterized in that the amino acid sequence of the bioactive peptide having an anti-obesity effect is one of QLGIK and NTDKQVT.

2. Application of the bioactive peptide having an anti-obesity effect according to claim 1 in the preparation of a product having an anti-obesity effect.

3. The application of the bioactive peptide having an anti-obesity effect according to claim 2 to the preparation of a product having an anti-obesity effect, characterized in that the product is a food, a pharmaceutical, or a health functional food.

4. The application of the bioactive peptide having an anti-obesity effect according to claim 3 to the preparation of a product having an anti-obesity effect, characterized in that the product further comprises an additive that is acceptable in food, pharmaceutical, or health functional foods.

5. A bioactive peptide preparation having an anti-obesity effect, characterized in that the active ingredient of the preparation is a bioactive peptide represented by at least one of QLGIK and NTDKQVT.

6. The bioactive peptide preparation having an anti-obesity effect according to claim 5, characterized in that the concentration of the active ingredient is 0.5 mg / mL.

7. The anti-obesity effect is characterized in that the anti-obesity effect is due to pancreatic lipase and α-amylase inhibitory activity, as described in claim 5 or 6, for a bioactive peptide preparation having an anti-obesity effect.

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