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CN-122011093-A - Pearl mussel blood glucose reducing polypeptide and application thereof

CN122011093ACN 122011093 ACN122011093 ACN 122011093ACN-122011093-A

Abstract

The invention discloses a pearl mussel blood sugar reducing polypeptide and application thereof, and the amino acid sequence of the pearl mussel blood sugar reducing polypeptide is shown as SEQ ID NO. 01. The pearl mussel hypoglycemic polypeptide has an IC 50 value of 0.293 mmol/L for alpha-glucosidase and an IC 50 value of 34.78 mu mol/L for dipeptidyl peptidase-IV, can effectively inhibit postprandial blood sugar rise, promote insulin secretion, and is suitable for the adjuvant therapy and blood sugar management of type II diabetics.

Inventors

  • CAO MINJIE
  • ZHENG KAIHONG
  • ZHANG LINGJING

Assignees

  • 集美大学

Dates

Publication Date
20260512
Application Date
20260209

Claims (10)

  1. 1. A pearl mussel blood sugar reducing polypeptide is characterized in that the amino acid sequence of the pearl mussel blood sugar reducing polypeptide is shown as SEQ ID NO. 01.
  2. 2. The method for preparing the pearl mussel hypoglycemic polypeptide according to claim 1, which is characterized by comprising the following steps: (1) Washing and cutting pearl mussel, mixing with buffer solution with pH=8-9, homogenizing, adding alkaline protease, performing primary enzymolysis at 45-55deg.C for 2-3 h, stopping primary enzymolysis, cooling to room temperature, adjusting pH to neutrality, adding neutral protease, performing secondary enzymolysis at 45-55deg.C for 2-3 h, and stopping primary enzymolysis, cooling to room temperature to obtain crude enzymolysis solution; (2) Sequentially centrifuging the crude enzymolysis liquid obtained in the step (1) to obtain supernatant and performing ultrafiltration separation to obtain a component < 3 kDa; (3) And (3) separating the component < 3 kDa obtained in the step (2) by gel chromatography and reversed-phase high performance liquid chromatography in sequence.
  3. 3. The method according to claim 2, wherein in the step (1), the ratio of the pearl mussel meat to the buffer solution is 1 g:6 mL.
  4. 4. The method according to claim 3, wherein the alkaline protease is added in an amount of 0.7 to 1.0% in the step (1).
  5. 5. The method according to claim 4, wherein the neutral protease is added in an amount of 0.5 to 0.8% in the step (1).
  6. 6. The method according to claim 1 to 5, wherein in the step (3), the gel chromatography is performed by using SuperdexTM Peptide 10/300. 300 GL gel filtration column.
  7. 7. The method according to claim 6, wherein the eluent used in the gel chromatography is ultrapure water, and the flow rate of the eluent is 0.3-0.5 mL/min.
  8. 8. The method according to claim 1 to 5, wherein in the step (3), the reversed-phase high-performance liquid chromatography is performed by using ZORBAX SB-C 18 column.
  9. 9. The method according to claim 8, wherein in the eluent of the phase high performance liquid chromatography separation, mobile phase A is ultrapure water containing 0.1% of trifluoroacetic acid, mobile phase B is acetonitrile containing 0.1% of trifluoroacetic acid, flow rate is 0.5 mL/min, and column temperature is 25 ℃.
  10. 10. Use of the pearl oyster hypoglycemic polypeptide according to claim 1 in the preparation of a hypoglycemic composition.

Description

Pearl mussel blood glucose reducing polypeptide and application thereof Technical Field The invention belongs to the technical field of biology, and particularly relates to a pearl mussel blood sugar reducing polypeptide and application thereof. Background Diabetes is a common chronic metabolic disorder characterized by a sustained elevation of blood glucose levels, and is largely divided into type I and type II, with type II diabetes being the highest priority. The disease is often caused by insufficient insulin secretion or insulin resistance, resulting in imbalance in the regulation of blood glucose in the body. Studies have shown that postprandial hyperglycemia is a typical symptom of early diabetes, whereas α -glucosidase acts as a key enzyme in the small intestine, catalyzing the breakdown of carbohydrates into glucose, promoting its absorption. By inhibiting the activity of alpha-glucosidase, the digestion of carbohydrate can be delayed, and postprandial blood glucose peak can be reduced, so that the progress of diabetes can be effectively controlled. In addition, dipeptidyl peptidase-IV (DPP-IV) is a serine protease that is capable of rapidly degrading incretins such as glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). These hormones are critical in stimulating insulin secretion and inhibiting glucagon release, and once degraded by DPP-IV, reduce insulin levels, exacerbating elevated blood glucose. Thus, DPP-IV inhibitors can enhance insulin secretion and maintain glycemic homeostasis by protecting the integrity of GLP-1 and GIP. Clinically usual hypoglycemic agents include alpha-glucosidase inhibitors such as acarbose, and DPP-IV inhibitors such as sitagliptin. Most of the medicines are chemical synthetic products, and can effectively regulate and control blood sugar in a short period, but obvious side effects are often associated with long-term use. For example, acarbose may trigger gastrointestinal reactions such as abdominal distension, diarrhea and increased intestinal gas, while sitagliptin, etc., may increase the risk of hypoglycemia and potentially impair liver and kidney function. These limitations have prompted research into safer natural alternatives. Bioactive peptides of food origin as an emerging option show significant advantages of low toxicity, low side effects, high bioavailability and easy absorption. The peptides can play a role in reducing blood sugar by competitively inhibiting enzyme activity or regulating related metabolic pathways, and become ideal components for auxiliary treatment of diabetes. In recent years, active peptides obtained from various animal and plant proteins through enzymolysis have been demonstrated to have the potential of inhibiting alpha-glucosidase and DPP-IV, and the peptide fragments tend to be simple in structure and stable in activity, and are convenient to develop into functional foods or dietary supplements. The pearl mussel is a freshwater bivalve mollusk widely distributed in rivers and lakes in China, has the advantages of rapid growth, strong fertility and wide adaptability, and is mainly used for freshwater pearl culture. However, in the pearl production process, enterprises usually only extract pearls, and byproducts such as mussel meat and the like are directly discarded or utilized in a low value, for example, the byproducts are used as feed, so that the resource waste is serious. The pearl mussel has high nutritive value, especially contains rich protein, accounts for more than 50% of dry weight, and is rich in essential amino acids and potential bioactive components. If the proteins can be processed by proper technology, the proteins are converted into high added value products, so that the economic benefit can be improved, and the sustainable utilization of resources can be realized. Enzymolysis is an effective method for extracting protein active peptide, and by selecting proper protease, macromolecular protein can be degraded into small molecular peptide fragments, and the peptide fragments can retain or enhance specific biological activity, such as blood sugar reducing effect. In the prior art, the utilization of pearl mussel meat is mainly limited to simple extraction or feed processing, and an optimized enzymolysis process aiming at the hypoglycemic activity is lacking. The parameters of the enzymatic hydrolysis such as enzyme type, pH, temperature, amount of enzyme added and time directly affect the yield and activity of the peptide, and often the active peptide is not fully released by a single enzymatic hydrolysis, while the degree of hydrolysis can be increased by multiple enzymatic hydrolysis steps, resulting in more low molecular weight components. These low molecular weight peptides can be further enriched by separation purification techniques such as ultrafiltration, gel chromatography and high performance liquid chromatography, and sequences can be identified using De novo sequencing a