CN115819508A - Isolated oligopeptide and application thereof in preparation of hypoglycemic drugs or foods - Google Patents

Abstract

The invention provides a separated oligopeptide and application thereof in hypoglycemic drugs or foods, wherein the separated oligopeptide has a nucleotide sequence shown in SEQ ID NO: 1. The separated oligopeptide disclosed by the invention has the effect of reducing blood sugar, and has important significance for development and application of hypoglycemic drugs, health-care foods or formula foods with special medical application, diabetes research and the like.

Description

Isolated oligopeptide and its application in the preparation of hypoglycemic drugs or food

technical field

The present invention relates to the field of biology. Specifically, the present invention relates to isolated oligopeptides and their use in hypoglycemic drugs or foods.

Background technique

Diabetes mellitus is a metabolic disease characterized by relative or absolute insulin deficiency and hyperglycemia as the main symptom. Elevated blood sugar caused by diabetes will cause chronic damage to human organs, leading to dysfunction of blood vessels, heart, liver, kidneys and other organs. Most of the anti-diabetic drugs currently used in clinical practice are chemical and biological agents, which have clear curative effects but are expensive, often accompanied by side effects such as weight gain, hypoglycemia, and gastrointestinal adverse reactions. Therefore, it has become a hot spot for researchers to screen out hypoglycemic drugs with low price and less side effects from natural products.

At present, studies have reported that some peptides have hypoglycemic effects. Compared with conventional chemical drugs, hypoglycemic peptide drugs have the advantages of simple structure, no immunogenicity, and low side effects. However, the vast majority of hypoglycemic peptide drugs will be degraded by proteases in the gastrointestinal tract after oral intake, and cannot exert their physiological functions. At the same time, hypoglycemic peptide drugs have strong hydrophobicity and poor intestinal absorption effect. Therefore, there is an urgent need to develop hypoglycemic peptide drugs that have both anti-enzymatic properties in the gastrointestinal tract and good intestinal absorption.

Contents of the invention

The present invention aims to solve the technical problems existing in the prior art at least to a certain extent. For this reason, the present invention proposes isolated oligopeptides, isolated nucleic acid molecules, constructs, recombinant cells, medicines, health foods, or formula foods for special medical purposes and uses. The isolated oligopeptides of the present invention have hypoglycemic effects, and have The development and application of blood sugar drugs, health foods or formula foods for special medical purposes, as well as diabetes research are of great significance.

In one aspect of the invention, the invention provides an isolated oligopeptide. According to an embodiment of the present invention, the isolated oligopeptide has the amino acid sequence shown in SEQ ID NO: 1, specifically, the amino acid sequence of the isolated oligopeptide is Phe-Gly-Ala-Trp-Thr-Pro -Arg. The inventors of the present invention have found that the above-mentioned isolated oligopeptides (in the present invention, also referred to as "lowering sugar peptides") can effectively reduce blood sugar levels, relieve insulin resistance, and improve blood lipid metabolism disorders caused by high blood sugar levels. The development and application of blood sugar drugs, health foods or formula foods for special medical purposes, as well as diabetes research are of great significance.

In another aspect of the invention, the invention provides an isolated nucleic acid molecule. According to an embodiment of the present invention, the isolated nucleic acid molecule encodes the aforementioned isolated oligopeptide. After the isolated nucleic acid molecule according to the embodiment of the present invention is introduced into the recipient cell, the aforementioned isolated oligopeptide can be expressed in an environment suitable for protein expression to exert its hypoglycemic effect.

In yet another aspect of the invention, the invention proposes a construct. According to an embodiment of the present invention, said construct comprises the aforementioned isolated nucleic acid molecule. After the construct according to the embodiment of the present invention is introduced into the cells, the aforementioned isolated oligopeptide is expressed in an environment suitable for protein expression, which helps to exert the hypoglycemic effect of the oligopeptide.

In yet another aspect of the present invention, the present invention provides a recombinant cell. According to an embodiment of the present invention, the recombinant cell contains the aforementioned isolated nucleic acid molecule or the aforementioned construct. Thus, expressing the above-mentioned oligopeptide in an environment suitable for protein expression is helpful for exerting the hypoglycemic effect of the oligopeptide. The recombinant cells of the present invention do not comprise germ cells, fertilized egg cells or embryo cells.

In yet another aspect of the present invention, the present invention provides a medicine, health food or formula food for special medical purposes. According to an embodiment of the present invention, the medicine, health food or formula food for special medical purpose includes: the aforementioned isolated oligopeptide, isolated nucleic acid molecule or recombinant cell. Therefore, the medicine, health food or formula food for special medical purpose according to the embodiment of the present invention has hypoglycemic effect.

In yet another aspect of the present invention, the present invention proposes the use of the aforementioned isolated oligopeptides, isolated nucleic acid molecules or recombinant cells in the preparation of medicines, health foods or formula foods for special medical purposes. According to an embodiment of the present invention, the medicine, health food or formula food for special medical purpose is used for lowering blood sugar.

According to an embodiment of the present invention, the medicine is used for preventing or treating diabetes.

Compared with prior art, the beneficial effect of the present invention is:

(1) The hypoglycemic peptide of the present invention is obtained by simulated digestion in the gastrointestinal tract, and can resist the secondary hydrolysis of protease in the gastrointestinal tract after oral administration, and has the characteristics of stability, safety, and no side effects.

(2) The present invention combines computer software to comprehensively evaluate the isoelectric point, hydrophilicity, stability, toxicity, steric hindrance and human intestinal absorption of the hypoglycemic peptide, and learn that it meets the requirements for oral drug or food development.

(3) The hypoglycemic peptide of the present invention can improve the fasting blood glucose level and insulin resistance of diabetic mice, reduce the content of total cholesterol and triglyceride in serum, and can be used in the preparation of special medical formula food, health products and The field of medicine has broad application prospects.

Additional aspects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Description of drawings

The above and/or additional aspects and advantages of the present invention will become apparent and comprehensible from the description of the embodiments in conjunction with the following drawings, wherein:

Fig. 1 has shown the influence of the hypoglycemic peptide according to one embodiment of the present invention on the glucose tolerance of diabetic mice, * represents that there is a significant difference (P<0.05) compared with the normal group; # represents that the difference is significant compared with the model group (P<0.05); 0.05);

Figure 2 shows the effect of hypoglycemic peptides according to an embodiment of the present invention on the insulin content in the serum of diabetic mice, and different lowercase letters represent significant differences (P<0.05);

Figure 3 shows the effect of hypoglycemic peptides according to one embodiment of the present invention on the total cholesterol content in the serum of diabetic mice, and different lowercase letters represent significant differences (P<0.05);

Fig. 4 shows the effect of hypoglycemic peptides according to an embodiment of the present invention on the serum triglyceride content of diabetic mice, and different lowercase letters represent significant differences (P<0.05).

Detailed ways

Embodiments of the present invention are described in detail below. The embodiments described below are exemplary only for explaining the present invention and should not be construed as limiting the present invention.

The present invention provides an isolated oligopeptide. According to an embodiment of the present invention, the amino acid sequence of the isolated oligopeptide is SEQ ID NO: 1, specifically, the amino acid sequence of the isolated oligopeptide is Phe-Gly-Ala-Trp-Thr-Pro-Arg (SEQ ID NO: 1 ). in,

Phe means the amino acid residue whose English name is Phenylalanine and Chinese name is phenylalanine;

Gly means the amino acid residue whose English name is Glycine and Chinese name is glycine;

Ala means the amino acid residue whose English name is Alanine and Chinese name is alanine;

Trp means the amino acid residue whose English name is Tryptophan and Chinese name is tryptophan;

Thr means the amino acid residue whose English name is Threonine and Chinese name is threonine;

Pro means the amino acid residue whose English name is Proline and Chinese name is proline;

Arg represents the amino acid residue whose English name is Arginine and Chinese name is arginine.

The isolated oligopeptide of the present invention has a molecular weight of 33.95 Da, is easily soluble in water, and has good stability. As an oligopeptide substance with a small molecular weight and a clear structure, its amino acid sequence determines that it has gastrointestinal tract resistance to enzymatic hydrolysis And good intestinal absorption effect, it is beneficial to develop into medicine, health food or formula food for special medical use.

The present invention does not strictly limit the source of the isolated oligopeptide, which can be extracted from natural materials or obtained by chemical synthesis. The natural materials can be plants, such as millet, barley, oats, and quinoa.

The present invention does not strictly limit the form of food for special medical treatment, health food or medicine. Food for special medical treatment can be gel food, porous food, powder food, pasty food, etc.; health food can be tablet, capsule ( soft, hard), water pills, granules (powders), oral liquids, liquors, teabags, etc.; the dosage form of drugs can be mixtures, injections, tablets, granules, syrups, capsules, oral liquids, aerosols Agents and sprays etc.

The present invention does not strictly limit the way of intake of special medical food, health food or medicine. Health food can only enter through the digestive tract, such as oral, chewing, lozenges, etc.; special medical food can be taken orally or tube feeding The route of administration is convenient for people with restricted food intake; the drug administration methods can be peritoneal, intravenous, intramuscular, subcutaneous, cortical, oral, nasal, pulmonary and rectal.

In the present invention, the term "treatment" is used to refer to obtaining a desired pharmacological and/or physiological effect. The effect may be prophylactic in terms of complete or partial prevention of the disease or its symptoms, and/or therapeutic in terms of partial or complete cure of the disease and/or adverse effects caused by the disease. "Treatment" as used herein encompasses disease in mammals, especially humans, including: (a) preventing a disease (such as preventing diabetes) or a condition in a predisposed individual who has not yet been diagnosed with the disease; (b) inhibiting the disease, such as arresting the development of the disease; or (c) ameliorating the disease, eg, reducing symptoms associated with the disease. "Treatment" as used herein encompasses any administration of a drug or compound to an individual to treat, cure, alleviate, ameliorate, lessen or inhibit a disease in the individual, including but not limited to the administration of isolated oligopeptides, isolated nucleic acid molecules as described herein Or recombinant cell drugs are given to individuals in need.

The solutions of the present invention will be explained below in conjunction with examples. Those skilled in the art will understand that the following examples are only for illustrating the present invention and should not be considered as limiting the scope of the present invention. If no specific technique or condition is indicated in the examples, it shall be carried out according to the technique or condition described in the literature in this field or according to the product specification. The reagents or instruments used were not indicated by the manufacturer, and they were all commercially available conventional products.

Example 1

Using computer software to predict the function of the hypoglycemic peptide (Phe-Gly-Ala-Trp-Thr-Pro-Arg), wherein the isoelectric point, hydrophilicity, and stability were passed through the ExPasy toolkit (https://web.expasy. org/protparam/); toxicity and steric hindrance were assessed by the ToxinPred toolkit (https://webs.iiitd.edu.in/raghava/toxinpred/index.html); human intestinal absorption was assessed by the admetSAR toolkit (http ://lmmd.ecust.edu.cn/admetsar1/home/) evaluation.

Table 1 Functional prediction of hypoglycemic peptides

Isoelectric point average hydrophilicity instability index toxicity Steric hindrance human intestinal absorption 9.75 -0.50 -35.80 none 0.57 +

Note: The greater the negative value of the average hydrophilicity, the stronger the hydrophilicity, and the instability index less than 40 indicates that it can exist stably.

As shown in Table 1, the hypoglycemic peptide is alkaline, with an isoelectric point of 9.75, strong hydrophilicity and good stability. At the same time, the peptide is non-toxic, has good absorption in the human intestinal tract, and its low steric hindrance is conducive to its binding to specific receptors and exerting physiological functions.

Example 2

The hypoglycemic peptide sequence (Phe-Gly-Ala-Trp-Thr-Pro-Arg) is chemically synthesized to obtain a synthetic peptide, and its hypoglycemic effect is verified through animal experiments. The specific steps are as follows:

Thirty-six 4-week-old C57BL/6J male mice were provided by Beijing Weitong Lihua Experimental Animal Technology Co., Ltd. After adaptive feeding for 1 week, the mice were divided into three groups: the normal control group was fed with low-fat diet, and the model group and intervention group were fed with high-fat diet. The model group and the intervention group were fasted for 12 hours and injected with 100 mg/kg STZ intraperitoneally at the fifth week to establish a type II diabetes model. The intervention group was given 200 mg/kg of hypoglycemic peptide every day, and the model group was given the same amount of normal saline every day. After 4 weeks of continuous gavage, fasting for 12 hours, the mice were gavaged with glucose solution at a dose of 1 g/kg, and then blood glucose was measured at 0, 15, 30, 60, 90, and 120 min using a blood glucose meter. After continuous gavage for 5 weeks, blood was collected from the orbit, the mice were killed by dislocation, and the contents of insulin, total cholesterol and triglyceride in serum were measured.

As shown in Figure 1, compared with the normal group, the blood glucose of the mice in the model group rose sharply after glucose injection, indicating that their glucose tolerance was significantly impaired. The blood glucose level of the mice in the intervention group was lower than that of the model group, and was significantly lower than that of the model group at 120 minutes, indicating that the hypoglycemic peptide can improve the glucose tolerance of diabetic mice.

As shown in Figure 2, compared with the normal group, the insulin content of the mice in the model group was significantly increased, indicating that insulin resistance occurred in them. After the intervention of the hypoglycemic peptide, the insulin content of the intervention group mice was significantly lower than that of the model group, indicating that the hypoglycemic peptide can improve insulin resistance in diabetic mice.

As shown in Figures 3 and 4, compared with the normal group, the total cholesterol and triglyceride contents of the mice in the model group were significantly increased, indicating that their blood lipid metabolism was disturbed. The total cholesterol and triglyceride content of the mice in the intervention group were significantly lower than those in the model group, indicating that the hypoglycemic peptide has the effect of improving blood lipid metabolism disorders in diabetic mice.

Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention, those skilled in the art can make the above-mentioned The embodiments are subject to changes, modifications, substitutions and variations.

Claims (7)

1. An isolated oligopeptide, characterized in that the isolated oligopeptide has an amino acid sequence as shown in SEQ ID NO:1. 2. An isolated nucleic acid molecule, characterized in that, the isolated nucleic acid molecule encodes the isolated oligopeptide of claim 1. 3. A construct comprising the isolated nucleic acid molecule of claim 2. 4. A recombinant cell, characterized in that the recombinant cell contains the isolated nucleic acid molecule of claim 2 or the construct of claim 3. 5. A medicine, health food or formula food for special medical purposes, characterized by comprising: the isolated oligopeptide as claimed in claim 1, the isolated nucleic acid molecule as claimed in claim 2 or the recombinant cell as claimed in claim 4. 6. Use of the isolated oligopeptide of claim 1, the isolated nucleic acid molecule of claim 2 or the recombinant cell of claim 4 in the preparation of medicines, health food or formula food for special medical purposes, characterized in that the The above-mentioned drugs, health foods or formula foods for special medical purposes are used to lower blood sugar. 7. The use according to claim 6, characterized in that the medicament is used for preventing or treating diabetes.

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