JP2001233898A - Antihypertensive peptide derived from meat protein - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide new peptides having antihypertensive action or angiotensin I-converting enzyme-inhibiting activity obtained from meat ranked as important food, and to provide a pharmacological composition comprising at least one of the peptides as an active component. SOLUTION: A peptide composition comprising pentapeptides having respective structures of Met-Asn-Pro-Pro-Lys and Ile-Thr-Thr-Asn-Pro is obtained by hydrolyzing meat protein or myosin of a principal meat protein by the action of a protease such thermolysin or protease K. These two pentapeptides and respective tripeptides having partial amino acid sequences Met-Asn-Pro and Pro-Pro-Lys of one of the pentapeptides have both of angiotensin I-converting enzyme-inhibiting activity and antihypertensive action. These peptides are highly safe and can be applied to food for prophylaxis of hypertension and amelioration of its symptom.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a protein produced by decomposing meat (animal meat) protein with a protease.
The present invention relates to a peptide that inhibits the activity of angiotensin I converting enzyme, and a pharmacological composition containing such a peptide or a salt thereof as an active ingredient, for preventing and / or ameliorating a disease such as hypertension caused by angiotensin I converting enzyme. .

[0002]

2. Description of the Related Art The renin-angiotensin system is known as an in vivo system which is deeply involved in the onset of hypertension, and angiotensin I which is an important component of this system is known.
The converting enzyme acts on angiotensin I to generate angiotensin II having a blood pressure increasing effect, and the angiotensin I converting enzyme also has a function of degrading bradykinin, a peptide having a hypotensive effect. That is, the angiotensin I converting enzyme raises blood pressure by two actions, that is, generation of a pressor peptide and decomposition of the antihypertensive peptide. Therefore, when hypertension is caused by such an action of angiotensin I converting enzyme, an increase in blood pressure can be suppressed by inhibiting the activity of angiotensin I converting enzyme. Furthermore, in recent years,
Angiotensin I converting enzyme inhibitors have also attracted attention for uses other than antihypertensive agents, such as therapeutic agents for heart failure.

[0003] As an inhibitor of angiotensin I converting enzyme, a peptide derived from a viper has been found as a natural product, and captopril has been found as a chemically synthesized material. In recent years, angiotensin I-converting enzyme inhibitors derived from foods and food raw materials have been receiving attention due to the growing interest in safety for pharmaceuticals and functionality for foods. In particular, a large number of searches for peptidic angiotensin I converting enzyme inhibitors produced by the degradation of food proteins have been conducted. Examples of such a product include peptides produced by protease degradation such as milk casein, soy protein, and corn protein (JP-A-8-283173, JP-A-8-2690).
No. 87, JP-A-8-99994, JP-A-6-99994
No. 87886). In addition, as an example using fish meat as a raw material, from bonito and protease decomposition products of sardines,
It is known to obtain peptides having angiotensin I converting enzyme inhibitory activity and blood pressure lowering activity (Bioscience,
Biotechnology and Biochemistry, 56, 1541-1545, 199
2, JP-A-7-188282). In addition, there is also known an example in which a blood pressure lowering peptide is prepared from a protease degradation product of plasma prepared from pig blood (Japanese Patent Laid-Open No. 5-2 / 1993).
38946). However, there is no known example of obtaining such a peptide from animal meat such as pork or beef or a protein contained in animal meat.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide novel peptides having an antihypertensive activity or angiotensin I converting enzyme inhibitory activity from meat, which is regarded as important in foods, and to use these peptides effectively. An object of the present invention is to provide a pharmacological composition containing as a component.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies in order to solve the above-mentioned problems, and as a result, they have been shown by SEQ ID NO: 1 which is a pentapeptide produced by the action of protease from meat protein myosin. (Met-Asn-
Pro-Pro-Lys) or (Ile-Thr-Thr-A
sn-Pro) was found to have angiotensin I converting enzyme inhibitory activity and blood pressure lowering effect, and completed the present invention.

That is, the present invention provides a peptide having an angiotensin I converting enzyme inhibitory activity or a salt thereof, which comprises all or a part of the amino acid sequence shown in SEQ ID NO: 1 or SEQ ID NO: 2 in the sequence listing. 1)
Peptides having angiotensin I converting enzyme inhibitory activity are Met-Asn-Pro-Pro-Lys, Met-Asn-Pro, Asn-Pro-Pr
o, Pro-Pro-Lys, Ile-Thr-Thr-Asn-Pro, Ile-Thr-Thr,
The peptide having angiotensin I converting enzyme inhibitory activity or a salt thereof (claim 2) according to claim 1, which is a peptide represented by either Thr-Thr-Asn or Thr-Asn-Pro.

[0007] The present invention also relates to a peptide comprising the amino acid sequence shown in SEQ ID NO: 1 or SEQ ID NO: 2 in whole or in part and having an angiotensin I converting enzyme inhibitory activity or a salt thereof as an active ingredient. A pharmacological composition (Claim 3) or a peptide having angiotensin I converting enzyme inhibitory activity is characterized in that Met-Asn-Pro-
Pro-Lys, Met-Asn-Pro, Asn-Pro-Pro, Pro-Pro-Lys, Il
e-Thr-Thr-Asn-Pro, Ile-Thr-Thr, Thr-Thr-Asn, Thr-A
4. The pharmacological composition according to claim 3, which is a peptide represented by any of sn-Pro, and the peptide having angiotensin I converting enzyme inhibitory activity contains myosin or myosin. 5. The pharmacological composition according to claim 3 or 4, wherein the raw material is obtained by subjecting the raw material to protease treatment, and the raw material containing myosin is a protein constituting a myofibril of animal meat. Pharmaceutical composition according to claim 5 (claim 6)
Or the protease is one or two selected from thermolysin, proteinase K, pronase E and papain.
6. A protease of at least one kind.
Or a pharmacological composition according to claim 6 (claim 7) or an agent for preventing and / or improving symptoms caused by an angiotensin I converting enzyme. The pharmaceutical composition according to any one of claims 3 to 7, which is a composition (claim 8) or a food for preventing and / or improving symptoms caused by an angiotensin I converting enzyme. Regarding item 9).

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The peptide having angiotensin I converting enzyme inhibitory activity of the present invention includes SEQ ID NO: 1 (Met-Asn-Pro-Pro-Lys) or SEQ ID NO: 2 (Ile-T
hr-Thr-Asn-Pro) and contains a peptide having angiotensin I converting enzyme inhibitory activity and a part of the amino acid sequence shown in SEQ ID NO: 1 or SEQ ID NO: 2 in the sequence listing. Any peptide may be used as long as it has angiotensin I converting enzyme inhibitory activity, and specific examples thereof include peptides represented by any of the following (1) to (14). (1) Met-Asn-Pro-Pro-Lys (2) Met-Asn-Pro (3) Asn-Pro-Pro (4) Pro-Pro-Lys (5) Ile-Thr-Thr-Asn-Pro (6 ) Ile-Thr-Thr (7) Thr-Thr-Asn (8) Thr-Asn-Pro (9) Met-Asn-Pro-Pro (10) Asn-Pro-Pro-Lys (11) Ile-Thr-Thr -Asn (12) Thr-Thr-Asn-Pro (13) Leu-Ile-Thr-Thr-Asn-Pro (14) Ile-Thr-Thr-Asn-Pro-Tyr

The novel peptides shown in the above (1) to (14) have an L-form amino acid sequence and are white powder at room temperature. In the present invention, the salt of the peptide is not particularly limited as long as it is a pharmacologically acceptable salt, and hydrochloride, sulfate, and phosphate of the peptide having angiotensin I converting enzyme inhibitory activity of the present invention are used. salt,
Salts such as citrate can be exemplified. Also,
Examples of a method for producing the peptide having angiotensin I converting enzyme inhibitory activity of the present invention include a method of separating and purifying from a protease or a degradation product of meat or meat protein, and a method of chemically synthesizing based on amino acid sequence information. Can be.

Angiotensin I using protease
As a raw material in the method for producing a peptide having a converting enzyme inhibitory activity, the pentapeptide represented by SEQ ID NO: 1 and SEQ ID NO: 2 of the present invention is a part of the amino acid sequence of myosin, a protein constituting myofibrils. do it,
Myosin or a raw material containing myosin is used. As such myosin, in addition to purified products, unpurified myosin and actomyosin can be exemplified.Examples of raw materials containing such myosin include myosin such as meat chunks, minced meat, remaining meat, scrap meat, and muscle. Meat (animal meat) containing 4 to 5% and myofibril constituent proteins containing 40 to 50% of myosin such as muscle-derived water-insoluble protein obtained from such meat can be exemplified.・
The origin and the like are not particularly limited. The protease is not particularly limited as long as a peptide solution having a strong angiotensin I converting enzyme inhibitory activity can be obtained. Other proteases include thermolysin (SIGMA) and proteinase K (MERCK). Proteases such as Pronase E (manufactured by MERCK) and Papain (manufactured by Tokyo Kasei Kogyo) can be exemplified as preferred proteases.

Degradation of a protein containing myosin by a protease is carried out, for example, by adding myosin or a raw material containing myosin to water or an appropriate buffer (for example, a phosphate buffer).
In addition, the myosin concentration is 0.01 to 10%, preferably 0.1 to 10%.
Suspension is performed to a concentration of about 1 to 3.0%, and protease is added to this solution at 0.01 to 10 g / L, preferably 0.1 to 10 g / L.
The enzyme reaction is carried out by adding at a concentration of about 05 to 2 g / L, and the enzyme reaction conditions are not particularly limited as long as the protease can act. An enzyme treatment condition of about 18 hours can be exemplified. In addition, the decomposition reaction by protease is performed by heating, addition of inorganic acid or organic acid,
Stopping can be accomplished by any of the commonly known methods, such as protease removal by ultrafiltration.
After the reaction is stopped, the insolubles are removed by filtration or centrifugation, and the resulting filtrate (protein degradation solution)
Contains a peptide produced by the degradation of myosin, and the target peptide can be purified from this solution by reversed-phase high-performance liquid chromatography or the like. The filtrate can be concentrated by freeze-drying or drying under reduced pressure, if necessary.

On the other hand, methods for producing peptides by a chemical synthesis method are roughly classified into a liquid phase method and a solid phase method. Although the synthesis by the solid phase method is becoming popular due to the recent spread of peptide synthesizers, any of these methods is used. The peptide having angiotensin I converting enzyme inhibitory activity of the present invention can be prepared by a conventional method. The peptide is produced by the solid phase method by using, for example, a peptide synthesizer model 430A manufactured by Applied Biosystems, and sequentially connecting the L-form amino acid from the carboxyl terminal side of the peptide to be synthesized to a polymer solid support by peptide bond. After elongating to synthesize the desired peptide chain, the peptide chain is cleaved from the solid support using trifluoromethanesulfonic acid or the like, and then the protecting group of the amino acid side chain is removed, followed by purification by a method such as reversed-phase high-performance chromatography. By obtaining the desired peptide.

The pharmacological composition of the present invention is not particularly limited as long as it contains the peptide having the inhibitory activity of angiotensin I converting enzyme of the present invention or a salt thereof as an active ingredient. A prophylactic and / or symptom-improving agent for a disease caused by an angiotensin I-converting enzyme such as hypertension and heart failure, and a food for preventing and / or improving a symptom; Examples can be given. As a pharmacological composition comprising such a mixture of the peptide of the present invention and / or a salt thereof and other components or materials, more specifically, a treatment for hypertension in which an excipient is added to the peptide of the present invention or a salt thereof Examples of the food include a drug, a food to which the peptide of the present invention or a salt thereof is added, a food material containing the peptide of the present invention or a salt thereof, and a food to which the food material is added. Foods include coffee, tea, sencha, yogurt, juice, milk, soy milk, sports drinks and other beverages, breads, cakes, jellies, buns, chewing gums and other breads and confectionery, udon, buckwheat noodles, etc. , Kamaboko, fish meat paste products such as fish sausage, dressings, mayonnaise, seasonings such as sweeteners, tofu,
Examples include konjac and other various side dishes.

A food material containing the peptide of the present invention or a salt thereof can be prepared inexpensively and in large quantities using meat chunks, remaining meat and scrap meat as raw materials. For example, when a meat mass is used as a raw material, the meat mass from which adipose tissue and connective tissue have been removed is ground, and approximately 4 times the amount of water and an appropriate amount of protease are added to the obtained ground meat, followed by stirring with a silent cutter or the like. After reacting at 37 ° C. for 12 to 18 hours to produce the peptide of the present invention, the protease is heated at 98 ° C. for 10 minutes to inactivate the protease, and then, if necessary, filtered and purified to obtain the present peptide. A food material containing the peptide of the invention can be prepared. When the remaining meat and scrap meat are used as raw materials, the remaining meat and scrap meat are first grinded, and a salt solution (for example, a 0.5 M NaCl solution) is added to the obtained ground meat, followed by stirring with a silent cutter or the like. After extracting salt-soluble proteins such as myosin and actin, the insoluble matter is removed by centrifugation or filtration, and the salt concentration is reduced by adding 4 to 5 times the amount of water to the extraction solution, whereby myosin, actin, etc. The food containing the peptide of the present invention is obtained by precipitating the salt-soluble protein and subjecting the insoluble protein recovered as an insoluble matter by centrifugation or filtration to protease treatment or the like in the same manner as in the case of the above meat mass. The material can be prepared.

[0015]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the technical scope of the present invention is not limited to the following examples. Unless otherwise specified, "%" shown in Examples represents% by weight. Example 1 [Isolation of a peptide having angiotensin I converting enzyme inhibitory activity] (Preparation of insoluble protein from porcine skeletal muscle) Porcine skeletal muscle (biceps femoris) was minced to remove fat and connective tissue as much as possible. 200 g of distilled water was added to 100 g, and homogenized until almost uniform. This was passed through a fine-meshed wire net to remove uncut pieces, and then filtered using filter paper. After filtration, the insoluble matter on the filter paper was further washed with distilled water until the filtrate became colorless. After washing, the insoluble matter on the filter paper was collected and freeze-dried to obtain a powdery insoluble porcine skeletal muscle protein. Further, it was confirmed by SDS-polyacrylamide gel electrophoresis that the major proteins contained in such proteins were myosin and actin.

(Production of Peptide from Porcine Skeletal Muscle Insoluble Protein Fraction) To 10 g of the above pig skeletal muscle insoluble protein was added 90 ml of distilled water, and the mixture was stirred until uniform. Eight proteases, namely thermolysin (SIGM)
A), proteinase K (manufactured by MERCK), proteinase E (manufactured by MERCK), phytin (manufactured by Tokyo Chemical Industry), papain (manufactured by Tokyo Chemical Industry), trypsin (manufactured by Wako Pure Chemical Industries; 2000 units / g) ), Α-chymotrypsin (manufactured by Wako Pure Chemical Industries; bovine pancreas) and pepsin (manufactured by Wako Pure Chemical Industries; 1: 10,00)
0) was used alone. After adding and dissolving 10 mg of one of the above proteases to the insoluble protein suspension, the mixture was reacted at 37 ° C. for 18 hours to produce a peptide. After the reaction was completed, the solution was heated at 98 ° C. for 10 minutes to inactivate the protease. Most of the insoluble matter was removed by centrifugation, and further fine particles were removed through a membrane filter to obtain eight kinds of peptide solutions. For measurement of angiotensin I converting enzyme inhibitory activity,
Eight kinds of sample solutions obtained by diluting the peptide solution 10-fold with distilled water were used.

(Production of Peptide from Myosin) 10 mg of swine myosin (manufactured by SIGMA) was added to and suspended in 10 ml of distilled water, and the above-mentioned eight proteases (thermolysin, proteinase K, proteinase E, Eight kinds of peptide solutions were obtained using 1 mg of ficin, papain, trypsin, chymotrypsin and pepsin) in the same manner as in the case of the above-mentioned insoluble protein of pig skeletal muscle. For the measurement of angiotensin I converting enzyme inhibitory activity, eight kinds of sample solutions obtained by diluting these peptide solutions 10 times with distilled water were used.

(Measurement of angiotensin I converting enzyme inhibitory activity) Angiotensin I converting enzyme inhibitory activity was measured by using a synthetic substrate, hippuric acid-L-histidyl-leucine (manufactured by SIGMA). Using the method of selectively cleaving L-histidyl-L-leucine of the terminal dipeptide of the above, free hippuric acid was extracted and colorimetrically performed. A test tube is charged with 0.015 ml of a sample solution (peptide solution) to be measured, and 0.125 ml of a substrate solution (7.6 M using a 0.1 M borate buffer containing 608 mM sodium chloride, pH 8.3) is added.
mM hippuric acid-L-histidyl-leucine) was added thereto, and the mixture was kept at 37 ° C for 5 minutes.
Thereafter, 0.05 ml of an enzyme solution (an angiotensin I converting enzyme produced by SIGMA, dissolved in distilled water to a concentration of 50 units / ml) was added and reacted at 37 ° C. for 30 minutes. After the reaction was stopped by adding 0.125 ml of 1N hydrochloric acid, 0.75 ml of ethyl acetate was added, and hippuric acid extracted into the ethyl acetate was quantified by measuring the absorbance at 228 nm. The absorbance of the sample solution was set to "S", the absorbance of a control using the same amount of distilled water in place of the sample solution was set to "B", the absorbance before the start of the reaction was set to "C", and the angiotensin I converting enzyme inhibition rate was calculated as follows. It was calculated by the equation. Inhibition rate (%) = (B−S) Ｂ (B−C) × 100

(Results of Measurement of Inhibitory Activity of Angiotensin I-Converting Enzyme) The eight kinds of sample solutions prepared by decomposing porcine skeletal muscle insoluble protein with various proteases and the eight kinds of sample solutions prepared by decomposing myosin with various proteases Table 1 shows the angiotensin I converting enzyme inhibitory activity of the sample solution. Porcine skeletal muscle insoluble protein thermolysin,
The sample solution treated with proteinase K, papain and pronase E had an inhibitory activity of 70% or more, and the sample solution treated with thermolysin and chymotrypsin on myosin had an inhibitory activity of 70% or more.

[0020]

[Table 1]

(Purification of angiotensin I converting enzyme inhibitory peptide) 100 ml of distilled water was added to 100 mg of pork myosin (manufactured by SIGMA) and suspended. After adding and dissolving 10 mg of thermolysin, the mixture was reacted at 37 ° C. for 18 hours to generate a peptide from myosin. After completion of the reaction, the mixture was heated at 98 ° C. for 10 minutes to inactivate thermolysin. Most of the insoluble matter was removed by centrifugation, and the solution was passed through a membrane filter to remove fine particles to obtain a peptide solution. The angiotensin I converting enzyme inhibitory peptide was purified from the obtained peptide solution by reversed-phase high performance liquid chromatography. That is, the column was made of Shiseido's CAPCELL PAK C18 UG1.
Using eluent A (0.1%
Eluate B (0.1 mL of distilled water containing trifluoroacetic acid)
The elution was carried out with a linear gradient system (acetonitrile containing 5% trifluoroacetic acid).

(Peptide Structure Determination) The amino acid sequence of the purified peptide was determined by N-terminal amino acid analysis by an automatic Edman degradation method (gas phase method). A protein sequencer model 470A manufactured by Abride Biosystems was used as an automatic analyzer. The operation was performed as described in the product manual, and all the reagents used were those specified by Abride Biosystems. FIG. 1 shows a chromatogram obtained when reversed-phase high-performance liquid chromatography was performed using a thermolysin hydrolyzate of myosin as a sample. The eluate was collected at 5 minute intervals, and the angiotensin I converting enzyme inhibitory activity was measured. As a result, the highest activity was observed in the fraction of 25 to 30 minutes. FIG. 2 shows a chromatogram when this fraction was again subjected to high performance liquid chromatography under the same conditions. High angiotensin I converting enzyme inhibitory activity was detected in the two peak portions (1) and (2) indicated by arrows at elution times around 26.3 minutes and 27.7 minutes.

Next, these parts were collected and structural analysis was performed. As a result, it was found that several kinds of peptides were present. Therefore, the eluate C (distilled water containing 0.015% ammonia) was further extracted from the eluate C. Reversed-phase high-performance chromatography was performed using an alkaline eluent by a linear gradient system on D (acetonitrile containing 0.015% ammonia). The peptide showing angiotensin I converting enzyme inhibitory activity contained in the fraction of peak (1) in FIG. 2 was detected at an elution time of about 26.5 minutes when an alkaline eluate was used. On the other hand, the inhibitory active peptide contained in the fraction of peak (2) in FIG.
It eluted around 1 minute. Each peptide was purified into a single component by reverse-phase high performance liquid chromatography using the alkaline eluate.

Structural analysis of the two purified peptides revealed that each was a pentapeptide consisting of five amino acid residues. These structures are as follows. (1) Met-Asn-Pro-Pro-Lys (derived from peak (1) in FIG. 2) (2) Ile-Thr-Thr-Asn-Pro (derived from peak (2) in FIG. 2) (Swiss-Prot), all of which were found to match the sequence present in the muscle myosin heavy chain. Met-Asn-Pr
o-Pro-Lys matched rat myosin heavy chain (residues 80 to 84), chicken myosin heavy chain (residues 80 to 84), and human myosin heavy chain (residues 82 to 86). On the other hand, Ile-Thr-Thr-Asn-Pro is rat myosin heavy chain (30
Residues 4-308), chicken myosin heavy chain (305-
309) and human myosin heavy chain (residues 306-310). The numbers of amino acid residues are all from the N-terminal side.

The myosin used in the present invention is derived from porcine skeletal muscle, but the sequence of the porcine myosin heavy chain has not yet been determined. Although the amino acid sequence of swine myosin was registered in the database (Swiss-Prot), no sequence completely matching the pentapeptide of the present invention was found. However, the registered pork myosin heavy chain sequence also
Gln-Asn-Pro-Pro-Lys (residues 79 to 83) and Ile-Thr-A
A sequence that differs from the pentapeptide of the present study, sn-Asn-Pro (residues 303 to 307), by one residue each, is present at the same position as in myosin derived from almost all kinds of animals. According to the results in humans, it is considered that the portion differing by one residue was erroneously read when the sequence of the porcine myosin heavy chain registered in the database was determined. Therefore, the sequence corresponding to the pentapeptide of the present invention is considered to be present at residues 79 to 83 and 303 to 307 of the porcine myosin heavy chain.

Example 2 [Chemical synthesis of pentapeptide and the like] (Chemical synthesis method) Two kinds of pentapeptides (Met-Asn-Pro-Pr
o-Lys, Ile-Thr-Thr-Asn-Pro) and the six tripeptides (Met-Asn-Pro, Asn-Pro-P) contained in these sequences
ro, Pro-Pro-Lys, Ile-Thr-Thr, Thr-Thr-Asn, Thr-Asn
The chemical synthesis of -Pro) was performed using a peptide synthesizer model 430A manufactured by Abride Biosystems according to the description in the product manual. All reagents used were those specified by Abride Biosystems. After the peptide chain was synthesized, it was cleaved from the solid support with trifluoromethanesulfonic acid. Next, the protecting group on the amino acid side chain was removed, and the target pentapeptide was purified by reversed-phase high-performance chromatography. The high performance liquid chromatography was performed under the conditions using the acidic eluate of Example 1.

(Chemically synthesized peptide angiotensin I
Measurement of converting enzyme inhibitory activity) The measurement of angiotensin I converting enzyme inhibitory activity was performed in the same manner as in the method described in Example 1 above. The peptide concentration at an inhibition rate of 50% was defined as an IC ₅₀ value. Table 2 shows the molecular weights and angiotensin I converting enzyme inhibitory activities of two pentapeptides and six tripeptides prepared by chemical synthesis. The value of the molecular weight of the synthesized peptide measured by a mass spectrometer (FAB-MAS) almost coincided with the value calculated from the chemical structure, and it was judged that the target peptide was synthesized without any problem. The angiotensin I converting enzyme inhibitory activity was highest with the tripeptide Met-Asn-Pro.

[0028]

[Table 2]

(Hypertensive Action of Chemically Synthetic Peptide) The hypotensive action of the above two pentapeptides and the six tripeptides contained in these sequences was examined using spontaneously hypertensive rats. Each of these synthetic peptides was forcibly administered to spontaneously hypertensive rats (Charles River Japan, 5 animals per group, 18 to 27 weeks old, male) using a gastric tube. The peptide dose was 1 mg per kg of rat body weight, and the dose volume was 1 ml per rat.
In addition, the thermolysin hydrolyzate of myosin prepared in Example 1 was also administered. As the thermolysin hydrolyzate, a freeze-dried peptide solution before dilution with distilled water in Example 1 was used.
30 mg / g. In addition, the thing which administered physiological saline orally was set as the control. The systolic blood pressure value in the tail artery was measured 6 hours after administration with the gastric sonde, and the value obtained by subtracting the systolic blood pressure value immediately before administration was calculated as a fluctuation value (blood pressure decrease value). The blood pressure was measured using a non-invasive blood pressure measuring device (Soft-lon, BP-98A) and tail cuff (ta
(i cuff) method. Table 3 shows the results. In all samples, blood pressure drop was measured 6 hours after administration. Of these, two pentapeptides (Met-Asn-
In the administration of Pro-Pro-Lys, Ile-Thr-Thr-Asn-Pro), two tripeptides (Met-Asn-Pro, Pro-Pro-Lys), and the thermolysin hydrolyzate of myosin, significant (P < 0.01).

[0030]

[Table 3]

[0031]

According to the present invention, by using meat as a raw material, a peptide having a function of lowering blood pressure and the like can be obtained at low cost. Further, the peptide of the present invention
Since it is a meat-derived peptide, it is highly safe and can be used not only as a pharmacological composition for medicine, but also useful as a material for producing high-value-added functional foods having a hypotensive effect and the like.

[0032]

[Sequence List] SEQUENCE LISTING <110> Prima Meat Packers, Ltd. <120> Pressure Reducing Peptide Derived from Meat Protein <130> 2000P568 <140> <141> <160> 2 <170> PatentIn Ver. 2.1 <210> 1 <211> 5 <212> PRT <213> Artificial Sequence <220> <223> Description of Artificial Sequence: Synthetic Peptide <400> 1 Met Asn Pro Pro Lys 1 5 <210> 2 <211> 5 <212> PRT < 213> Artificial Sequence <220> <223> Description of Artificial Sequence: Synthetic Peptide <400> 2 Ile Thr Thr Asn Pro 1 5

[Brief description of the drawings]

FIG. 1 is a diagram showing a chromatogram obtained when reverse-phase high-performance liquid chromatography is performed using a thermolysin hydrolyzate of myosin as a sample.

FIG. 2 is a view showing a chromatogram when the active fraction shown in FIG. 1 is again subjected to reverse-phase high-performance liquid chromatography.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) A61P 9/12 C07K 5/083 43/00 111 5/093 C07K 5/083 5/097 5/093 C12N 9 / 99 5/097 C12P 21/02 B C12N 9/99 A61K 37/02 // C12P 21/02 37/12 (72) Inventor Masanobu Akimoto 635 Nakamukaihara, Tsuchiura-shi, Ibaraki Primaham Co., Ltd. (72) Invention Person Takashi Samejima 635 Nakamukaihara, Tsuchiura-shi, Ibaraki Primaham Co., Ltd. (72) Inventor Kazuo Motono 635 Nakamuhara, Tsuchiura-shi, Ibaraki Primaham Co., Ltd. AG21 CA21 CC03 CD20 DA06 DA10 4C084 AA01 AA02 BA01 BA22 CA25 MA52 NA14 ZA422 4C087 AA01 AA02 BB47 CA16 MA52 NA14 ZA42 4H045 AA10 AA30 BA12 BA13 CA40 DA57 EA23 FA34 FA70 GA15 GA22 GA25

Claims (9)

[Claims] 1. A peptide having an angiotensin I converting enzyme inhibitory activity or a salt thereof, which comprises all or part of the amino acid sequence shown in SEQ ID NO: 1 or SEQ ID NO: 2 in the sequence listing. 2. The angiotensin I converting enzyme inhibitor according to claim 1, wherein the peptide having angiotensin I converting enzyme inhibitory activity is a peptide represented by any of the following (1) to (8): An active peptide or a salt thereof. (1) Met-Asn-Pro-Pro-Lys (2) Met-Asn-Pro (3) Asn-Pro-Pro (4) Pro-Pro-Lys (5) Ile-Thr-Thr-Asn-Pro (6 ) Ile-Thr-Thr (7) Thr-Thr-Asn (8) Thr-Asn-Pro 3. A peptide comprising all or a part of the amino acid sequence represented by SEQ ID NO: 1 or SEQ ID NO: 2 in the sequence listing, and comprising, as an active ingredient, a peptide having angiotensin I converting enzyme inhibitory activity or a salt thereof. Pharmacological composition. 4. The pharmaceutical composition according to claim 3, wherein the peptide having angiotensin I converting enzyme inhibitory activity is a peptide represented by any of the following (1) to (8). (1) Met-Asn-Pro-Pro-Lys (2) Met-Asn-Pro (3) Asn-Pro-Pro (4) Pro-Pro-Lys (5) Ile-Thr-Thr-Asn-Pro (6 ) Ile-Thr-Thr (7) Thr-Thr-Asn (8) Thr-Asn-Pro 5. The pharmaceutical composition according to claim 3, wherein the peptide having angiotensin I converting enzyme inhibitory activity is obtained by subjecting myosin or a raw material containing myosin to protease treatment. 6. The pharmacological composition according to claim 5, wherein the raw material containing myosin is a protein constituting myofibrils of animal meat. 7. The protease, wherein the protease is selected from thermolysin, proteinase K, pronase E and papain.
7. The pharmacological composition according to claim 5, wherein the pharmacological composition is a species or two or more types of proteases. 8. The pharmaceutical composition according to any one of claims 3 to 7, which is an agent for preventing and / or improving symptoms caused by angiotensin I converting enzyme. 9. The pharmacological composition according to claim 3, which is a food for preventing and / or improving symptoms caused by a disease caused by angiotensin I converting enzyme.