A protein peptide with ACE inhibitory activity and application thereof

Abstract

The application discloses preparation and application of lotus seed protein peptide with ACE inhibitory activity, and belongs to the technical field of food-derived active peptide development. The ACE inhibitory peptide is quickly screened by using polypeptidomics and molecular docking technology, so that the shortcomings of time consumption and labor caused by step-by-step separation and purification are avoided. The obtained ACE inhibitory peptide WVPRYFPF has very high ACE inhibitory activity, and the IC 50 is 16.7 μM, and can be used for assisting or replacing high blood pressure drugs. The lotus seed protein peptide has the characteristics of inhibiting ACE enzyme activity in vitro, and animal experiments prove that the protein peptide can also play a blood pressure lowering effect in spontaneously hypertensive rats (SHR).

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of food-derived bioactive peptide development, and particularly relates to a protein peptide with ACE inhibitory activity and application thereof. BACKGROUND

[0002] Hypertension is a common disease, which generally has a slow onset. Typical symptoms include headache, fatigue or restlessness, arrhythmia, palpitations, tinnitus, etc. If not treated properly, it can cause other health problems such as stroke, myocardial infarction, and renal failure. High systolic blood pressure can cause more than 10 million deaths worldwide each year. The types of antihypertensive drugs used clinically include angiotensin-converting enzyme inhibitors (ACEI), beta-receptor blockers, calcium channel blockers, diuretics, etc., with ACEI being the main type. So far, synthetic antihypertensive drugs such as captopril and lisinopril have good antihypertensive effects, but long-term use can have certain side effects, such as sinus tachycardia, inferior myocardial infarction, cough, dizziness, etc. It is an urgent need to find safe and effective bioactive substances that can inhibit ACE and thus achieve the effect of lowering blood pressure.

[0003] The regulation mechanism of blood pressure is complex, including the renin-angiotensin system (RAAS system) and the kallikrein-kinin system (KKS system). In the RAAS system, angiotensin I (AngI) released by the liver is further hydrolyzed into angiotensin II (AngII) with vasoconstrictor function by angiotensin enzyme (ACE enzyme), thereby increasing the body's blood pressure. At the same time, AngII binds to the AT1 receptor to release aldosterone (ALD), promoting the reabsorption of water and sodium ions, leading to an increase in sodium concentration and blood volume, resulting in an increase in the body's blood pressure.

[0004] Many food-derived proteins do not have antihypertensive activity themselves, but through enzymatic hydrolysis or fermentation, the proteins are broken down to release peptide segments with antihypertensive activity. At present, a large number of highly active ACE inhibitory peptides have been isolated from various food-derived proteins, showing good antihypertensive effect. For example, the patent with publication number CN115947781A discloses producing antihypertensive peptides using fermented wheat as raw material. For another example, the patent with publication number CN117247425A discloses a method for producing antihypertensive peptides using corn germ protein as raw material. Such natural peptides can avoid the side effects of synthetic drugs, but the types of plant-derived antihypertensive peptides reported so far are limited, and new plant antihypertensive peptides need to be developed. SUMMARY

[0005] This section is intended to introduce some aspects of one or more embodiments of the present application, which are described below. This section is not intended to limit the scope or content of the application in any way. The concepts described herein can apply equally to any embodiment of the application.

[0006] The present application is proposed in view of the above and / or problems in the prior art.

[0007] Therefore, the purpose of the present application is to overcome the deficiencies in the prior art, and to provide a protein peptide with ACE inhibitory activity.

[0008] To solve the above technical problems, the present application provides the following technical solutions: A protein peptide with ACE inhibitory activity, characterized in that the amino acid sequence of the protein peptide is WVPRYFPF, i.e. Trp-Val-Pro-Arg-Tyr-Phe-Pro-Phe.

[0009] Another purpose of the present application is to overcome the deficiencies in the prior art, and to provide an application of a protein peptide in the preparation of a blood pressure lowering product.

[0010] Another purpose of the present application is to overcome the deficiencies in the prior art, and to provide a method for screening and identifying a protein peptide with ACE inhibitory activity, characterized in that it comprises,

[0011] Lotus seed protein is extracted from lotus seed powder by alkali dissolution and acid precipitation;

[0012] Lotus seed peptides are produced by hydrolyzing the lotus seed protein with protease;

[0013] Ultrafiltration is used for separation and purification, and the component of <3kDa with almost twice the activity before ultrafiltration is selected for sequencing;

[0014] The <3kDa lotus seed peptides are sequenced by polypeptidomics;

[0015] Potential high-activity ACE inhibitory peptides are screened;

[0016] Molecular docking technology is used to verify the screened peptide segments;

[0017] Computer simulation of gastrointestinal digestion is performed;

[0018] Solid-phase synthesis in vitro and verification of ACE inhibitory activity are performed.

[0019] As a preferred solution of the method of the present application, the lotus seed protein is extracted from lotus seed powder by alkali dissolution and acid precipitation, and the ratio of lotus seed powder to water is 1:10 to 1:25.

[0020] As a preferred scheme of the method, the lotus seed protein is hydrolyzed by a protease to produce the lotus seed peptide, wherein the temperature of the hydrolysis is 45-60 DEG C, and the pH is 6.5-8.5.

[0021] As a preferred scheme of the method, the screening of the potential high-activity ACE inhibiting peptide comprises: performing biological activity prediction scoring on the peptide segment in PeptideRanker; querying the protein source of the peptide segment in a protein database; performing toxicity prediction by Toxinpred; performing allergenicity prediction by AllerTOP; selecting, from the sequenced peptide segment, a sequence with a protein source, no modification by a functional group, a peak area greater than 1.00*107, an activity score > 0.8, 3-12 amino acids, no toxicity and allergenicity, and no publication, and simultaneously screening the peptide segment with a hydrophobic amino acid at the C-terminal and the N-terminal.

[0022] As a preferred scheme of the method, the verification of the screened peptide segment by the molecular docking technology comprises:

[0023] Preparation of the ACE enzyme PDB file: retrieving the protein crystal structure of the ACE enzyme from a protein database, and removing the excess ligand and H2O from 1O86 to facilitate subsequent docking experiments with the peptide segment;

[0024] The screened peptide sequence is docked with 1O86 to obtain a binding energy, and the potential ACE inhibiting activity is evaluated according to the size of the binding energy; the lower the molecular docking binding energy, the stronger the potential ACE inhibiting activity.

[0025] As a preferred scheme of the method, the molecular docking binding energy of the screened peptide segment is less than -9.4 kcal / mol.

[0026] As a preferred scheme of the method, the computer simulation of the gastrointestinal digestion comprises: performing enzyme cutting on the peptide segment by BIOPEP-UWM: ANALYSIS function in the BIOPEP database; and selecting chymotrypsin A, trypsin and pepsin for simulation enzyme cutting.

[0027] The present application has the following beneficial effects:

[0028] (1) The lotus seed peptide extracted by the present application has higher in-vitro ACE inhibiting activity compared with other ten kinds of plant source ACE inhibiting peptides.

[0029] (2) The present application effectively identifies the high-activity ACE inhibiting peptide WVPRYFPF from the lotus seed protein peptide, and the IC 50The molecular docking result shows that the docking binding energy is -12.1 kcal / mol, WVPRYFPF forms pocket hydrogen bonds with His353 and His513 in the active pocket of ACE, forms non-pocket hydrogen bonds with Asn66, Arg124, Trp220, Tyr360, Ser517 and Arg522, and forms hydrophobic interactions with Tyr62, Glu123, Arg124, Glu143, Ile204, Ala207, Trp357, Phe512 and Val518.

[0030] (3) The lotus seed protein peptide with ACE inhibitory effect is isolated from lotus seed protein for the first time, and the polypeptide is verified by spontaneous hypertension rats (SHR) experiment, has good characteristics of reducing blood pressure of SHR rats in vivo, and shows good antihypertensive effect after 2 weeks of lotus seed peptide intervention. Therefore, the lotus seed peptide provided by the present application can be used for inhibiting ACE enzyme activity in vitro and preparing antihypertensive drugs, enriches the types of antihypertensive drugs, and greatly improves the medicinal value of lotus seed protein. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor. Among them:

[0032] Figure 1 It is an activity comparison chart of plant-derived ACE inhibitory peptides;

[0033] Figure 2 It is a schematic diagram of the molecular structure of WVPRYFPF;

[0034] Figure 3 It is the protein crystal structure of ACE;

[0035] Figure 4 It is a molecular docking and interaction force analysis chart of WVPRYFPF and ACE;

[0036] Figure 5 It is the ACE inhibition rate determination of WVPRYFPF;

[0037] Figure 6 It is a standard curve of Ang II concentration in rat serum;

[0038] Figure 7 It is the effect of lotus seed peptide on Ang II concentration in serum of spontaneous hypertension rats. DETAILED DESCRIPTION

[0039] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0040] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0041] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0042] The experimental materials and reagents used in the embodiments of this invention are as follows: lotus seed powder (Amway (Shanghai) Technology Development Co., Ltd.); complex protease (15000U / g) (Novozymes (China) Biotechnology Co., Ltd.); angiotensin-converting enzyme (ACE) and N-[3-(2-furanyl)acryloyl]-L-phenylalanyl-glycyl-glycine (FAPGG) (Sigma-Aldrich, USA); N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (HEPES) buffer (Shanghai Yuanye Biotechnology Co., Ltd.); and rat angiotensin II (AngII) ELISA kit (Shanghai Enzyme-Linked Biotechnology Co., Ltd.).

[0043] The instruments used in this invention embodiment are: SW22 electric thermostatic water bath (JULABO, Germany); LXJ-IIB centrifuge (Anting Instrument Factory, Shanghai); FE20K precision pH meter and AL104 electronic analytical balance (Mettler Instruments, Shanghai); LGJ-10E freeze dryer (Ningbo Sentz Biotechnology Co., Ltd.); Muliskan GO full-wavelength microplate reader (Thermo Fisher Scientific, China); and rat non-invasive sphygmomanometer (Kent, USA).

[0044] Example 1

[0045] This example compares the activities of ACE inhibitory peptides from various plant sources. By reviewing domestic and international literature, the IC50 values ​​of dozens of common plant-derived ACE inhibitory peptides were summarized. 50 Value. Result as follows Figure 1 As shown in the figure, the comparison reveals that the in vitro ACE inhibitory activity of lotus seed peptides is at a moderate to high level, with an IC50 value of [missing information]. 50The value is relatively low, has great research value, and lotus seeds, as mature seeds of Nymphaea tetragona Georgi, are widely used as food. Lotus seeds are rich in protein, about 19.0-25.0%, and the bioactive substances of lotus seed protein have not been widely studied compared with the phytochemicals (starch, phenolic substances) in lotus seeds. Therefore, subsequent in-depth research on ACE-inhibitory peptides from lotus seeds is needed.

[0046] Example 2

[0047] The present embodiment provides a method for obtaining lotus seed protein hydrolysate from lotus seed protein and separating and identifying ACE-inhibitory peptides, comprising the following steps:

[0048] (1) Extracting lotus seed protein from lotus seed powder by alkali dissolution and acid precipitation

[0049] After the lotus seed powder is sieved through an 80-mesh sieve, it is dissolved in water at a solid-liquid ratio of 1:10-1:25 (w / v), the pH is adjusted to 9.5-12.0 with NaOH, and the mixture is stirred at room temperature for 3.0-6.0 h, then centrifuged at 8000-10000 r / min for 10-30 min. The supernatant is collected, the pH is adjusted to the isoelectric point of 3.2-4.0 with HCl, and the mixture is allowed to stand for 20-40 min, then centrifuged at 8000-10000 r / min for 10-30 min. The supernatant is discarded, and the precipitate is redissolved in deionized water, the pH is adjusted to neutral 7.0, and the mixture is dialyzed in a dialysis bag at 4℃ for 2-3 days. Finally, the lotus seed protein is obtained by freeze-drying.

[0050] (2) Hydrolyzing lotus seed protein to produce lotus seed peptides using protease

[0051] An appropriate amount of lotus seed protein powder is weighed and prepared into a protein solution with a substrate concentration of 4-10%. The protein solution is preheated at 80-100℃ for 10-30 min to ensure that the lotus seed protein is denatured by heat. The temperature is adjusted to 45-60℃ and the pH is adjusted to 6.5-8.5 to achieve the optimal enzyme hydrolysis conditions for complex protease. Protease is added according to the enzyme-substrate ratio of 6000-12000 U / g protein. The reaction is continuously stirred, and the pH of the reaction system is maintained with NaOH until it is constant. After the hydrolysis is completed, the heating and stirring are stopped, and the mixture is placed in a boiling water bath for 10-30 min for enzyme inactivation treatment. The pH is then adjusted to 7.0 with HCl, and the mixture is centrifuged at 8000-10000 r / min for 10-30 min. The supernatant is collected and dialyzed in a dialysis bag at 4℃ for 2-3 days. After freeze-drying, the lotus seed peptides are obtained and stored at -20℃ for later use.

[0052] (3) Separation and purification by ultrafiltration, and selection of the component with high activity (<3 kDa) for subsequent sequencing

[0053] The lotus seed peptide in step (2) was dissolved in water and placed in a 50 mL ultrafiltration tube with a 3 kDa model. Centrifugation was performed at 3000-4000 r / min for 5-10 min, and the operation was repeated. The <3 kDa component under the ultrafiltration tube was taken and freeze-dried for standby.

[0054] (4) Sequencing of <3 kDa lotus seed peptides by peptidomics

[0055] The <3 kDa lotus seed peptide sample obtained in step (3) was analyzed by LC-MS / MS equipped with an online nanospray ion source. The complete system was a Q ExactiveTM mass spectrometer (Thermo Fisher Scientific, MA, USA) connected to an EASY-nanoLC 1200. A total of 5 μL of lotus seed proteolytic sample (analysis column: Acclaim PepMap C18, 75 μm x 25 cm) was loaded, and the sample was separated with a 120 min gradient, the column flow was controlled at 300 nL / min, the column temperature was 40℃, the electrospray voltage was 2 kV, the gradient was started from 2% B phase, increased to 35% at 110 minutes, and increased to 100% within 1 minute, and maintained for 9 minutes. The mass spectrometer was operated in data-dependent acquisition mode, and automatically switched between MS and MS / MS acquisition.

[0056] The mass spectrometry parameters are as follows:

[0057] ① MS: scan range (m / z): 200-1800; resolution: 70000; AGC target: 3e6; maximum injection time: 60 ms; ② HCD-MS / MS: resolution: 17500; AGC target: 5e4; maximum injection time: 50 ms; collision energy: 27; dynamic exclusion time: 20 s. The tandem mass spectrum was analyzed by PEAKS Studio version 10.6 (Bioinformatics Solutions Inc., Waterloo, Canada). The PEAKSDB searched the uniprot_Cicer arietinum (version 202112, 24812 entries) database, and set None enzyme digestion. The search parameters were as follows: fragment ion mass tolerance: 0.02 Da, parent ion mass tolerance: 7 ppm, variable modification: Oxidation (M) 15.99, Deamidation (NQ) 0.98, Acetylation (Protein N-term) 42.01. The protein card value was: -10 lgP≥0, containing at least 1 unique peptide; the peptide segment card value was: -10 lgP≥20.

[0058] After sequencing the components of lotus seed protein hydrolysate <3kDa by polypeptidomics, 6534 polypeptides were identified.

[0059] (5) Screen potential high-activity ACE inhibitory peptides from the 6534 polypeptides identified in (4) using various screening conditions, mainly including the following steps:

[0060] ① Perform biological activity prediction scoring on the peptide segments in PeptideRanker (http: / / distilldeep.ucd.ie / PeptideRanker / );

[0061] ② Query the protein source of the peptide segments in the protein database (https: / / www.uniprot.org / );

[0062] ③ Perform toxicity prediction by Toxinpred (https: / / crdd.osdd.net / raghava / toxinpred / );

[0063] ④ Perform allergenicity prediction by AllerTOP (https: / / www.ddg-pharmfac.net / AllerTOP / );

[0064] ⑤ Select from the sequenced peptide segments those with the following characteristics: protein source, not modified by functional groups, peak area greater than 1.00 x 10 7 , activity score > 0.8, 3-12 amino acid sequence, no toxicity and allergenicity, and not yet published sequence, and simultaneously screen for peptide segments with hydrophobic amino acids at both C and N termini.

[0065] (6) Verify the peptide segments obtained from step (5) using molecular docking technology, mainly including the following steps:

[0066] ① Preparation of ACE enzyme PDB file: retrieve the protein crystal structure of ACE enzyme (code: 1O86) from the protein database, remove excess ligands and H2O from 1O86 for subsequent docking experiments with peptide segments;

[0067] ② After docking the screened peptide sequences with 1O86, obtain the binding energy, and evaluate the potential ACE inhibitory activity according to the size of the binding energy. The lower the molecular docking binding energy, the stronger the potential ACE inhibitory activity.

[0068] (7) Computer simulation of gastrointestinal digestion

[0069] Perform computer simulation of gastrointestinal digestion on the peptide segments with low molecular docking binding energy screened in step (6) to see if the screened peptide segments have the potential to resist gastrointestinal digestion. The specific steps are as follows:

[0070] ① The peptide segments were subjected to enzyme digestion by BIOPEP-UWM: ANALYSIS function in the BIOPEP database (https: / / biochemia.uwm.edu.pl);

[0071] ② Chymotrypsin A, trysin, and pepsin (pH 1.3) were selected for simulated enzyme digestion, and the peptide segments that could resist digestion or still had potential activity after digestion were selected for subsequent solid-phase synthesis.

[0072] (8) In vitro solid-phase synthesis and verification of ACE inhibitory activity.

[0073] Specifically, 6 polypeptides were screened, and the molecular docking binding energy of the 6 polypeptides was less than -9.4 kcal / mol. The ACE inhibitory activity of the 6 polypeptides after in vitro solid-phase synthesis was verified, and the specific information is shown in Table 1.

[0074] Table 1 Molecular docking binding energy of 6 polypeptides and ACE

[0075]

[0076] The results show that the lotus seed protein-derived ACE inhibitory peptides obtained by the method of the present application have amino acid sequences of WVPRYFPF, GFEWISF, GDDGFEWISF, FALP, IFSGF, and FLPVLL, respectively.

[0077] Example 3

[0078] This embodiment is an activity detection method of ACE inhibitory peptides, which comprises the following steps:

[0079] In a 96-well plate, 40 μL of HEPES buffer (pH 8.2, 80 mmol / L, containing 0.3 mol / L NaCl) and a certain concentration of captopril (or sample solution to be tested) were added, then 50 μL of FAPGG (1 mmol / L) was added, and after preheating at 37°C for 10 min, 10 μL of 0.1 U / mL ACE was added to the 96-well plate. The initial absorbance values (A1 and B1) were measured at 340 nm, and then the endpoint absorbance values (A2 and B2) were measured after incubation at 37°C for 30 min in the dark.

[0080] The positive control was captopril.

[0081] The ACE inhibitory rate was calculated as follows:

[0082]

[0083] Wherein, A1-A2: absorbance changes of the blank group within 30 minutes; B1-B2: absorbance changes of the sample group within 30 minutes.

[0084] The results of ACE inhibitory activity assays are shown in Tables 2 and 3.

[0085] Table 2 Comparison of ACE inhibition rates before and after ultrafiltration

[0086]

[0087] The results showed that, within a certain concentration range, the ACE inhibitory activity of lotus seed peptides with a concentration <3kDa after ultrafiltration was significantly better than that of lotus seed peptides before ultrafiltration, with an IC50 value of [missing value]. 50 The concentration also decreased from 0.276±0.019 mg / mL before ultrafiltration to 0.122±0.014 mg / mL. Therefore, the fraction with <3 kDa after ultrafiltration was selected for sequencing.

[0088] Table 3 IC of 6 synthetic peptides 50 Test results

[0089]

[0090] The results showed that three peptides (WVPRYFPF, GFEWISF, and GDDGFEWISF) exhibited strong ACE inhibitory activity, with high IC50 values. 50 All were less than 200 μM, with WVPRYFPF exhibiting the strongest ACE inhibitory activity (IC50). 50 =16.7μM).

[0091] Example 4

[0092] This example describes the analysis of the ACE-inhibiting peptide WVPRYFPF, specifically:

[0093] (1) Structure of WVPRYFPF and ACE

[0094] like Figure 2 As shown, the molecular structure of WVPRYFPF was obtained from Chemdraw and Autodock.

[0095] like Figure 3 The image shows the protein crystal structure of ACE(1O86).

[0096] (2) WVPRYFPF docking with ACE molecules

[0097] like Figure 4As shown, WVPRYFPF forms pocket hydrogen bonds with His353 and His513 residues of ACE, forms non-pocket hydrogen bonds with Asn66, Arg124, Trp220, Tyr360, Ser517 and Arg522 residues, and forms hydrophobic interactions with Tyr62, Glu123, Arg124, Glu143, Ile204, Ala207, Trp357, Phe512 and Val518 residues.

[0098] (3) ACE IC of WVPRYFPF 50

[0099] According to the method of Example 3, the ACE inhibition rate of the polypeptide sample WVPRYFPF was determined at different concentrations, and plotted for analysis, to calculate the ACE half-inhibitory concentration (IC 50 ) of the polypeptide, i.e. the polypeptide concentration required for the ACE activity inhibition rate to reach 50%.

[0100] The results are shown in Figure 4 As shown, the IC 50 value of the polypeptide sample WVPRYFPF is 16.7 μM, which has a relatively low IC 50 value compared with the thousands of ACE inhibitory peptides reported in the BIOPEP-UWM database.

[0101] Example 5

[0102] This example is an experiment on the effect of lotus seed ACE inhibitory peptides on spontaneously hypertensive rats, including the following steps:

[0103] Spontaneously hypertensive rats (SHR), male, 12 weeks old, weighing 200 ± 20 g, a total of 18, before the experiment, the rats were individually housed in stainless steel cages, with light and darkness controlled at 12 h per day, temperature at 24℃, standard feed was used for the experiment, and the rats were adaptively fed for one week, during which adaptive measurement of blood pressure was performed to reduce stress reaction during the experiment. Before each measurement, the rats were placed on a 37℃ heating plate for preheating for 5-10 min, and then the measurement was performed, with 15 cycles set for each measurement, and at least 5 groups of effective data were collected for each rat.

[0104] The 18 rats were randomly divided into 3 groups, 6 rats in each group, and oral administration was used to reduce harm to the rats, and the 3 groups were a control group of sterile tap water, a positive control group of captopril, and an experimental group of lotus seed peptide intervention. Among them, the captopril administration dose was 0.05 mg / mL, and the lotus seed peptide concentration was 15 mg / mL, and the administration was performed once a day, continuously for 6 weeks, and the blood pressure of the rats was measured every two weeks, and the blood pressure was measured by the rat tail artery systolic pressure method.

[0105] During the experiment, the blood pressure of the blank control mice increased slightly with age, gradually increasing from about 215 mmHg at 12 weeks of age to about 220 mmHg at 14 weeks of age, after which the blood pressure stabilized and no longer increased. The blood pressure of the positive control group and the lotus seed peptide group began to decrease significantly after 2 weeks, with a decrease of 30-40 mmHg, and remained stable for 3-6 weeks without a significant upward trend.

[0106] like Figure 6 , 7 As shown, after 6 weeks of intervention, the angiotensin II (Ang II) content in the lotus seed peptide group was significantly lower than that in the blank control group and comparable to that in the positive control group (p<0.05). The experimental results indicate that the lotus seed protein peptide of the present invention reduces the production of angiotensin II (Ang II) by inhibiting ACE enzyme activity and regulating the RAAS system, thereby reducing blood pressure.

[0107] The above results indicate that the protein peptides of the present invention also have a good antihypertensive effect in vivo and can be used as raw materials for the development of antihypertensive drugs and functional foods, showing great development potential.

[0108] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the present invention.

Claims

1. A protein peptide having ACE inhibitory activity, characterized by The amino acid sequence of the protein peptide is WVPRYFPF, i.e. Trp-Val-Pro-Arg-Tyr-Phe-Pro-Phe.

2. Use of the protein peptide according to claim 1 in the preparation of antihypertensive drugs or health foods.

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