Microalgae polypeptide and application thereof in preparation of product for preventing and / or treating hyperuricemia

Abstract

The invention discloses a microalgae polypeptide and application thereof in preparation of a product for preventing and / or treating hyperuricemia, and belongs to the field of preparation and application of biological peptides. The microalgae polypeptide obtained by the invention comprises at least one of polypeptide 1, polypeptide 2 and polypeptide 3. The amino acid sequence of the polypeptide 1 is as shown in SEQ ID NO. 1; the amino acid sequence of the polypeptide 2 is LAW; the amino acid sequence of the polypeptide 3 is as shown in SEQ ID NO. 2. The prepared microalgae polypeptide component has good XOD inhibitory activity, and can be applied to preparation of uric acid reducing products and xanthine oxidase inhibitors. According to the invention, the utilization rate and industrial value of microalgae protein resources can be effectively improved, and meanwhile, a new technical idea and a new method are provided for prevention and treatment of hyperuricemia.

Description

Technical Field

[0001] This invention relates to the field of preparation and application of bioactive peptides, and in particular to a microalgal polypeptide and its application in the preparation of products for the prevention and / or treatment of hyperuricemia. Background Technology

[0002] Hyperuricemia (HUA) is a metabolic disorder primarily caused by purine metabolism disorders, leading to increased uric acid production and elevated blood uric acid levels. Additionally, impaired kidney function reduces uric acid excretion in urine, causing uric acid accumulation in the blood and contributing to the condition. Currently, hyperuricemia is considered the fourth highest-risk chronic disease, after hyperlipidemia, hypertension, and hyperglycemia. When uric acid concentration exceeds the body's metabolic threshold, it accumulates in large quantities, easily causing urate crystal deposition in tissues such as joints and kidneys, leading to gout. Hyperuricemia can also affect multiple organs, causing systemic damage. For example, when blood uric acid exceeds saturation, urate crystals can deposit in the synovial membrane and cartilage of joints, inducing gouty arthritis. Uric acid crystals deposited in the renal tubules can damage tubular function and, in the long term, can develop into chronic interstitial nephritis. When crystals accumulate in the renal collecting system, they form urate stones, causing renal colic, hematuria, and urinary tract obstruction. Hyperuricemia is an independent risk factor for cardiovascular diseases such as hypertension and coronary heart disease; urate crystals can damage vascular endothelium, promote inflammatory responses, and contribute to atherosclerosis. Hyperuricemia also frequently coexists with metabolic diseases such as obesity, type 2 diabetes, and hyperlipidemia, forming "metabolic syndrome," which further exacerbates metabolic disorders.

[0003] Xanthine oxidase (XOD) participates in a key step of purine metabolism in the human body. Its main function is to catalyze the oxidation of hypoxanthine to xanthine, which is then oxidized to uric acid, pyrimidines, and purines. Therefore, inhibiting XOD activity can lower serum uric acid levels, thereby alleviating or treating hyperuricemia (HUA). Traditional uric acid-lowering drugs (such as allopurinol and febuxostat) can inhibit XOD, but they have side effects such as liver and kidney damage, gastrointestinal discomfort, and allergic reactions, and are not tolerated by some people. In recent years, the development of safe and effective bioactive substances with XOD inhibitory capabilities from natural products has become a research hotspot. These substances can interact with XOD and alter its secondary structure, thereby reducing or inactivating the enzyme. Among them, uric acid-lowering peptides have received widespread attention due to their strong targeting, mild effects, good stability, combination of nutritional and physiological activity, and synergistic regulation of metabolism. They are not only suitable for adjunctive treatment of patients with hyperuricemia, but also for daily prevention in high-risk groups (such as obese individuals, those with a family history of gout, and long-term drinkers). Currently, researchers have discovered uric acid-lowering active peptides from various sources, such as uric acid-lowering peptides from walnut protein, skipjack tuna, rice protein, and shark cartilage, but research on microalgae protein-derived peptides is limited.

[0004] Chlorella proteoglycans, with a protein content exceeding 50%, possesses extremely high nutritional value and is an excellent raw material for preparing uric acid-lowering active peptides. Currently, there is a lack of research on screening potential active peptides from the enzymatic hydrolysis products of Chlorella proteoglycans, evaluating their efficacy, and determining their structure-activity mechanism. This invention aims to fill this gap, providing a new approach for the development of food-derived uric acid-lowering peptide products, and offering new ideas for the high-value and precise utilization of microalgal protein resources. Summary of the Invention

[0005] The purpose of this invention is to provide a microalgal polypeptide and its application in the preparation of products for the prevention and / or treatment of hyperuricemia, so as to solve the problems existing in the prior art. The microalgal polypeptide provided by this invention has good inhibitory activity against XOD and can be used to develop polypeptide products with uric acid-lowering activity, providing new technical ideas and new methods for the prevention and treatment of hyperuricemia.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] In a first aspect, the present invention provides a microalgal polypeptide, wherein the microalgal polypeptide includes at least one of polypeptide 1, polypeptide 2 and polypeptide 3.

[0008] Preferably, the amino acid sequence of polypeptide 1 is as shown in SEQ ID NO.1; the amino acid sequence of polypeptide 2 is LAW; and the amino acid sequence of polypeptide 3 is as shown in SEQ ID NO.2.

[0009] Secondly, the present invention also provides a method for preparing the microalgal polypeptide, comprising the following steps:

[0010] Add water to Chlorella pyrenoidosa powder, add compound enzyme and pre-treat with enzymatic hydrolysis at 50-60℃ for 2-4 hours. After enzyme inactivation treatment, homogenize under high pressure to obtain Chlorella pyrenoidosa protein solution.

[0011] Alkaline protease was added to the protein solution of Chlorella nucleus, and the enzyme was hydrolyzed at 50-60℃ for 3-4 hours. After enzyme inactivation and cooling, the supernatant was collected, desalted, and dried to obtain a microalgae polypeptide mixture powder.

[0012] The microalgae polypeptide mixture powder was reconstituted and then separated by ultrafiltration membrane ultrafiltration and gel filtration chromatography. The filtrate was collected, desalted, and dried to obtain the microalgae polypeptide.

[0013] Preferably, the composite enzyme used in the enzymatic hydrolysis pretreatment of the Chlorella proteinensis powder is cellulase and pectinase.

[0014] Preferably, the alkaline protease is Alcalase 2.4L alkaline protease.

[0015] Thirdly, the present invention also provides the application of the microalgal polypeptide described herein in the preparation of products for the prevention and / or treatment of hyperuricemia.

[0016] Preferably, the product is a drug.

[0017] Fourthly, the present invention also provides a product for the prevention and / or treatment of hyperuricemia, the product comprising the aforementioned microalgae polypeptide.

[0018] Fifthly, the present invention also provides the application of the microalgal polypeptide in the preparation of xanthine oxidase inhibitors.

[0019] In a sixth aspect, the present invention also provides a xanthine oxidase inhibitor, the active ingredient of which includes the aforementioned microalgal polypeptide.

[0020] The present invention discloses the following technical effects:

[0021] Compared with traditional microalgae protein peptide enzymatic hydrolysis preparation, this invention adopts enzymatic pretreatment + high-pressure homogenization to synergistically extract proteins, achieving "gentle enzymatic hydrolysis to break the structure + efficient physical cell wall disruption", that is: maximizing cell wall disruption efficiency, preserving protein activity under gentle conditions, reducing energy consumption to adapt to industrial production, and precisely solving the shortcomings of traditional methods such as incomplete cell wall disruption, easy loss of activity, and high energy consumption.

[0022] The microalgal polypeptides prepared in this invention exhibit excellent XOD inhibitory activity, several times greater than that of currently confirmed Chlorella-derived active peptides. They also possess superior uric acid-lowering activity and can be used to prepare XOD inhibitors and uric acid-lowering products. This invention effectively improves the utilization rate and industrial value of microalgal protein resources, while providing a new method for the prevention and treatment of hyperuricemia. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 See the Sephadex G-15 gel filtration chromatography curve;

[0025] Figure 2 Total ion chromatogram of the highly active uric acid-lowering peptide component of Chlorella proteoglycans;

[0026] Figure 3 This is a secondary mass spectrum of the urate-lowering peptides from FTQDW.

[0027] Figure 4 The secondary mass spectrum of LAW's urate-lowering peptides;

[0028] Figure 5 This is a secondary mass spectrum of the urate-lowering peptide from FGSGWAW;

[0029] Figure 6 The effect of different treatment groups on mouse body weight;

[0030] Figure 7 The effects of different treatment groups on organ coefficients in mice;

[0031] Figure 8 Images of the kidneys of mice in different treatment groups;

[0032] Figure 9 The effects of different treatment groups on serum biochemical parameters in mice. Detailed Implementation

[0033] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0034] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0035] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0036] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0037] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0038] The method for determining the XOD inhibition rate of each sample in the embodiments of the present invention is as follows:

[0039] Add 100 μL of the target active peptide solution and 50 μL of XOD solution (0.02 U / mL) to a 96-well plate, shake for 30 s to ensure homogeneity, and incubate at 25 °C for 5 min. Add 100 μL of xanthine solution (0.48 mmol / L), shake again for 30 s to mix, and incubate at 25 °C for 25 min. After the reaction, measure the absorbance at 290 nm. The formula for calculating XOD inhibitory activity is as follows:

[0040] Inhibition rate (%) = [1 - (A1 - A2) / (A3 - A4)] × 100;

[0041] In the formula, A1 represents the absorbance of the sample solution after adding the enzyme; A2 represents the absorbance of the sample solution without adding the enzyme; A3 represents the absorbance when the buffer solution is used as a blank control instead of the sample solution; and A4 represents the absorbance of the blank control without adding the enzyme.

[0042] Example 1: Preparation of a microalgal polypeptide mixture

[0043] (1) Protein extraction: Add 15 times the amount of water to the Chlorella pulvinata powder, freeze and thaw 3 times at -20℃, then add 20 U / g cellulase and 10 U / g pectinase according to the substrate mass, and enzymatically hydrolyze for 2.5 h at 50℃. After enzyme inactivation treatment, homogenize the material 3 times at a homogenization pressure of 50 MPa to obtain Chlorella pulvinata protein solution.

[0044] (2) Enzymatic hydrolysis preparation: Add 2.4 L of alkaline protease (Alcalase) to the protein solution obtained in (1), with an enzyme dosage of 2500 U / g, at a temperature of 50℃, a hydrolysis time of 3.5 h, and a hydrolysis pH of 8.5. After hydrolysis, inactivate the enzyme in a boiling water bath for 10 min and then cool to room temperature. Centrifuge the hydrolysate at 7000 r / min for 20 min and collect the supernatant. Desalt the supernatant using a nanofiltration membrane with a molecular weight cutoff of 200 Da at a pressure of 1.2 MPa, and cycle twice. Spray dry or freeze dry the desalted supernatant to obtain a microalgae polypeptide mixture powder.

[0045] Example 2 Preparation of a microalgal polypeptide mixture

[0046] (1) Protein extraction: Add 15 times the amount of water to the Chlorella pulvinata powder, freeze and thaw 3 times at -20℃, then add 20 U / g cellulase and 10 U / g pectinase according to the substrate mass, and enzymatically hydrolyze for 2.5 h at 50℃. After enzyme inactivation treatment, homogenize the material 3 times at a homogenization pressure of 50 MPa to obtain Chlorella pulvinata protein solution.

[0047] (2) Enzymatic hydrolysis preparation: Papain was added to the protein solution obtained in (1) at a dosage of 2500 U / g, a temperature of 50℃, a hydrolysis time of 3.5 h, and a hydrolysis pH of 7.0. After hydrolysis, the enzyme was inactivated by boiling water for 10 min and then cooled to room temperature. The hydrolysate was centrifuged at 7000 r / min for 20 min, and the supernatant was collected. The supernatant was desalted using a nanofiltration membrane with a molecular weight cutoff of 200 Da at a pressure of 1.2 MPa, and the treatment was repeated twice. The desalted supernatant was spray-dried or freeze-dried to obtain a microalgae polypeptide mixed product powder.

[0048] Example 3 Preparation of microalgal polypeptide mixture

[0049] (1) Protein extraction: Add 15 times the amount of water to the Chlorella pulvinata powder, freeze and thaw 3 times at -20℃, then add 20 U / g cellulase and 10 U / g pectinase according to the substrate mass, and enzymatically hydrolyze for 2.5 h at 50℃. After enzyme inactivation treatment, homogenize the material 3 times at a homogenization pressure of 50 MPa to obtain Chlorella pulvinata protein solution.

[0050] (2) Enzymatic hydrolysis preparation: Trypsin was added to the protein solution obtained in (1) at a dosage of 2500 U / g, a temperature of 37℃, a hydrolysis time of 3.5 h, and a hydrolysis pH of 8.0. After hydrolysis, the enzyme was inactivated by boiling water for 10 min and then cooled to room temperature. The hydrolysate was centrifuged at 7000 r / min for 20 min, and the supernatant was collected. The supernatant was desalted using a nanofiltration membrane with a molecular weight cutoff of 200 Da at a pressure of 1.2 MPa, and the treatment was repeated twice. The desalted supernatant was spray-dried or freeze-dried to obtain a microalgal polypeptide mixture powder.

[0051] The XOD inhibitory activity of the microalgal polypeptide mixtures prepared in Examples 1-3 was determined spectrophotometrically. The results showed that, at a concentration of 4 mg / mL, the XOD inhibition rate of the microalgal polypeptide mixture prepared using Alcalase 2.4L alkaline protease in Example 1 (51.73%) was higher than that of papain (42.85%) and trypsin (29.61%). Therefore, Alcalase 2.4L alkaline protease is more suitable for preparing highly active Chlorella peptides.

[0052] Example 4: Ultrafiltration separation of microalgal polypeptide mixtures

[0053] (1) The microalgal polypeptide mixture powder prepared in Example 1 was reconstituted with deionized water and ultrafiltered using an ultrafiltration membrane with a molecular weight cutoff of 3 kDa. The concentration of the mixed product was 5 mg / mL, the ultrafiltration pressure was 1.2 MPa, and the throughput was 2.5 L / h.

[0054] (2) Collect the retentate with a molecular weight less than 3 kDa and obtain the sample powder by freeze drying or spray drying.

[0055] Example 5: Ultrafiltration separation of microalgal polypeptide mixtures

[0056] (1) The microalgal polypeptide mixture powder prepared in Example 1 was reconstituted with deionized water and ultrafiltered using ultrafiltration membranes with molecular weight cutoffs of 3 kDa and 5 kDa. The concentration of the mixed product was 5 mg / mL, the ultrafiltration pressure was 1.2 MPa, and the throughput was 2.5 L / h.

[0057] (2) Collect the retentate with a molecular weight of 3kDa≤Mw≤5kDa and obtain the sample powder by freeze drying or spray drying.

[0058] Example 6: Ultrafiltration separation of microalgal polypeptide mixtures

[0059] (1) The microalgal polypeptide mixture powder prepared in Example 1 was reconstituted with deionized water and ultrafiltered using an ultrafiltration membrane with a molecular weight cutoff of 5 kDa. The concentration of the mixed product was 5 mg / mL, the ultrafiltration pressure was 1.2 MPa, and the throughput was 2.5 L / h.

[0060] (2) Collect the retentate with a molecular weight less than 5 kDa and obtain the sample powder by freeze drying or spray drying.

[0061] The XOD inhibition activity of ultrafiltration fractions with different molecular weights obtained in Examples 4-6 was determined. The results showed that, at a concentration of 4 mg / mL, the ultrafiltration fraction with a molecular weight cutoff of less than 3 kDa obtained in Example 4 exhibited a higher XOD inhibition activity (59.26%) than the other molecular weight cutoff fractions in Examples 5 (50.78%) and 6 (52.43%). Therefore, using Alcalase 2.4L alkaline protease for enzymatic hydrolysis and then obtaining fractions with a molecular weight cutoff of less than 3 kDa through ultrafiltration is more beneficial for screening highly active microalgal peptides.

[0062] The Chlorella enzymatic hydrolysis product components prepared in the above embodiments can effectively inhibit XOD activity, have high development value and application prospects, and can effectively improve the utilization rate of microalgae resources and industrial economic value.

[0063] Example 7: Gel filtration chromatography separation of ultrafiltration components

[0064] The component powder obtained in Example 4 was reconstituted with deionized water to prepare a 20 mg / mL solution, which was then purified using a Sephadex G-15 dextran gel. The sample loading volume was 10 mL, and the elution flow rate was 0.8 mL / min, yielding three peaks: A, B, and C. Figure 1 The components from these three different peaks were collected and freeze-dried, and their XOD inhibitory activity was determined. The results showed that at a concentration of 4 mg / mL, the XOD inhibition rates of the components corresponding to peaks A, B, and C were 60.19%, 65.64%, and 81.47%, respectively. The component from peak C was collected and freeze-dried to obtain the highly active protein-nucleated Chlorella urate-lowering peptide component.

[0065] Therefore, using Alcalase 2.4L alkaline protease for enzymatic hydrolysis and obtaining components with a molecular weight cutoff of less than 3kDa through ultrafiltration, followed by further purification by gel filtration chromatography, is more conducive to the preparation and screening of microalgal peptides with high XOD inhibition activity.

[0066] Example 8 Identification of uric acid-lowering polypeptide components

[0067] The highly active polypeptide components isolated and prepared in Example 7 were identified and screened using LC-MS / MS technology, including the following steps:

[0068] (1) Pretreatment: The highly active component obtained in Example 7 was desalted and dissolved in ultrapure water to a concentration of 0.5 mg / mL. After passing through a 0.22 μm filter membrane, it was placed in a sample bottle for testing.

[0069] (2) LC-MS / MS determination: The sample was injected into C 18 Capillary trapping column (100μm×20mm, 5μm), then passed through C 18 Gradient separation was performed using a separation column (75 μm × 150 mm, 3 μm). Mobile phase A was 0.1% (v / v) formic acid solution, and mobile phase B was 80% (v / v) acetonitrile solution (containing 0.1% formic acid, v / v). The column was equilibrated with 100% mobile phase A. The liquid chromatography separation gradient was as follows: 0–2 min, 98%–95% A, 2%–5% B; 2–44 min, 95%–72% A, 5%–28% B; 44–51 min, 72%–60% A, 28%–40% B; 51–53 min, 60%–0% A, 40%–100% B; 53–60 min, 0% A, 100% B. After the peptides were separated, they were analyzed by Q-Exactive mass spectrometry for 60 min.

[0070] (3) Peptide screening: The potential toxicity, sensitization and potential biological activity of peptides were predicted using the online platforms ToxinPred (https: / / webs.iiitd.edu.in / raghava / toxinpred / index.html), AllerCatPro (https: / / allercatpro.bii.a-star.edu.sg / ), and Peptide Ranker (http: / / distilldeep.ucd.ie / PeptideRanker / ).

[0071] The total ion chromatogram of the highly active uric acid-lowering peptide component of Chlorella proteoglycans is shown in the figure. Figure 2As shown in the figure. PEAKSStudio 10.6 software was used to process and analyze the raw mass spectrometry data from the Uniprot protein database, yielding 1267 peptides. The amino acid sequence lengths of all peptides ranged from 2 to 12. Based on peptide content, confidence score, and Peptide Ranker score, three small molecule peptides were selected (Table 1): FTQDW (SEQ ID NO.1), LAW, and FGSGWAW (SEQ ID NO.2), and their secondary mass spectra are shown in the figure. Figures 3-5 As shown.

[0072] Table 1. Identification of highly active urate-lowering peptides from Chlorella vulgaris.

[0073] peptides Allergenicity Peptide Ranker toxicity FTQDW (SEQ ID NO.1) none 0.74 none LAW none 0.88 none FGSGWAW (SEQ ID NO.2) none 0.96 none

[0074] The obtained peptides were subjected to activity verification. FTQDW, LAW, and FGSGWAW were all synthesized in solid phase by Shanghai Sangon Biotech Co., Ltd. (purity >95%). The XOD inhibition activity of the synthesized peptides was detected. The results showed that the IC50 values ​​of FTQDW, LAW, and FGSGWAW were [missing information]. 50 The concentrations were 3.36 mg / mL, 0.72 mg / mL, and 1.28 mg / mL, respectively. Based on the experimental results, it is preliminarily predicted that FTQDW, LAW, and FGSGWAW can be used as uric acid-lowering peptides. Among them, LAW showed the best inhibitory activity against XOD.

[0075] Experimental Example 1: Efficacy Evaluation

[0076] A HUA mouse model was established, and the efficacy of the LAW peptides obtained through the above isolation and screening was evaluated, including the following steps:

[0077] (1) Establishment, grouping and experimentation of HUA mouse model

[0078] SPF-grade male Kunming mice were selected and allowed free access to food and water in a standard experimental environment. After 7 days of acclimatization (weight measurement), the mice were divided into 5 groups based on their weight: normal group (n=6), model group (n=8), positive control group (n=8, allopurinol 15 mg / kg), low-dose peptide group (n=8, 80 mg / kg), and high-dose peptide group (n=8, 160 mg / kg). The model group, positive control group, low-dose peptide group, and high-dose peptide group received intraperitoneal injections of 300 mg / kg daily during the experiment. -1 A HUA mouse model was established by administering potassium oxonate and feeding mice with a standard diet containing 20% ​​yeast extract. Normal mice were fed a standard diet during the experiment. Both the normal and model groups were administered an equal volume (v / v) of sodium carboxymethyl cellulose solution by gavage daily. The positive control group was administered allopurinol (15 mg / kg) by gavage daily.-1 The low- and high-dose peptide groups were administered LAW uric acid-lowering peptide (80 mg / kg) obtained in Example 8 via gavage daily. -1 160 mg·kg -1 ) Administer intraperitoneally at the same time daily for three consecutive weeks.

[0079] (2) Indicator Measurement

[0080] After the final gavage, the mice were fasted for 8 hours but allowed free access to water. The mice were weighed, then anesthetized for blood collection. Serum was collected by centrifugation, and serum uric acid, creatinine, and blood urea nitrogen were measured. The liver and kidneys were harvested to calculate organ coefficients.

[0081] (3) Results Analysis

[0082] During the experiment, the normal group mice showed no physiological abnormalities and moved nimbly. A few mice in the model group exhibited sluggish movement and weight loss. Figure 6 This indicates that high uric acid may lead to metabolic disorders and weight loss. Compared with the model group, the mice in the low- and high-dose peptide groups showed a slow recovery in weight, and their food and water intake were normal. This suggests that the peptide fragments screened in this invention have no significant adverse effects on the physiological state of HUA mice and have a certain effect on the recovery of weight in HUA model mice.

[0083] Visceral indices are important indicators of mouse health. For example... Figure 7 As shown, compared with the normal group, the kidney and liver indices in the model group were significantly increased by 38.34% and 47.34%, respectively, indicating that the modeling method of potassium oxonate combined with yeast extract caused certain damage to the mouse organs. Compared with the model group, the kidney and liver indices in both the high- and low-dose peptide groups were significantly decreased. Similarly, Figure 8 It is evident that the kidneys of the model group mice showed a significant whitening effect, while the kidneys of the high-dose peptide group had a more normal color. This indicates that the uric acid-lowering peptide screened in this invention has a certain degree of protective effect against kidney damage caused by HUA.

[0084] Changes in serum uric acid concentration reflect the body's purine metabolism and are one of the important indicators for the clinical diagnosis of hyperuricemia. Figure 9 As shown, compared with the normal group, the serum uric acid level in the model group was significantly increased, indicating that the HUA mouse model was successfully established. Compared with the model group, the serum uric acid levels in the positive drug group and the low- and high-dose peptide groups were significantly reduced, decreasing by 73.13%, 43.81%, and 59.73%, respectively. Serum creatinine and blood urea nitrogen are important indicators for assessing renal function. Compared with the model group, the low- and high-dose peptide groups significantly reduced serum creatinine and blood urea nitrogen levels, indicating that this uric acid-lowering peptide can effectively alleviate HUA kidney damage induced by potassium oxonate combined with yeast extract.

[0085] In summary, the uric acid-lowering peptides screened from microalgae in this invention have good uric acid-lowering effects, and within a certain concentration range, the higher the dose of the uric acid-lowering peptides, the more significant their effects.

[0086] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A microalgal polypeptide, characterized in that, The microalgal polypeptides include at least one of polypeptide 1, polypeptide 2 and polypeptide 3.

2. The microalgal polypeptide according to claim 1, characterized in that, The amino acid sequence of polypeptide 1 is shown in SEQ ID NO. 1; the amino acid sequence of polypeptide 2 is LAW; and the amino acid sequence of polypeptide 3 is shown in SEQ ID NO.

2.

3. A method for preparing the microalgal polypeptide according to claim 1, characterized in that, Includes the following steps: Add water to Chlorella pyrenoidosa powder, add compound enzyme and pre-treat with enzymatic hydrolysis at 50-60℃ for 2-4 hours. After enzyme inactivation treatment, homogenize under high pressure to obtain Chlorella pyrenoidosa protein solution. Alkaline protease was added to the protein solution of Chlorella nucleus, and the enzyme was hydrolyzed at 50-60℃ for 3-4 hours. After enzyme inactivation and cooling, the supernatant was collected, desalted, and dried to obtain a microalgae polypeptide mixture powder. The microalgae polypeptide mixture powder was reconstituted and then separated by ultrafiltration membrane ultrafiltration and gel filtration chromatography. The filtrate was collected, desalted, and dried to obtain the microalgae polypeptide.

4. The preparation method according to claim 3, characterized in that, The compound enzymes used in the enzymatic hydrolysis pretreatment of Chlorella pyrenoidosa powder are cellulase and pectinase.

5. The preparation method according to claim 3, characterized in that, The alkaline protease is Alcalase 2.4L alkaline protease.

6. The use of the microalgae polypeptide of claim 1 in the preparation of products for the prevention and / or treatment of hyperuricemia.

7. The application according to claim 6, characterized in that, The product in question is a medicine.

8. A product for the prevention and / or treatment of hyperuricemia, characterized in that, The product includes the microalgae polypeptide described in claim 1.

9. The use of the microalgal polypeptide of claim 1 in the preparation of xanthine oxidase inhibitors.

10. A xanthine oxidase inhibitor, characterized in that, The active ingredient includes the microalgal polypeptide as described in claim 1.

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