369 results about "Pepsin" patented technology

The invention relates to a method for screening and preparing a horse milk whey protein source antioxidant peptide and application of the horse milk whey protein source antioxidant peptide. The polypeptide with potential antioxidant activity is screened out by predicting information of the polypeptide through virtual enzymolysis and a computer and then performing molecular docking with the keap1 protein. The feasibility of obtaining the antioxidant peptide is verified by simulating gastrointestinal digestion with pepsin, trypsin and chymotrypsin. Finally, in-vitro chemical antioxidant activity verification is carried out through chemical synthesis of the high-purity antioxidant peptide, and it is found that the antioxidant peptide has good free radical scavenging activity. An oxidative damage model is induced by H2O2 on cells, and it is found that the antioxidant peptide can resist cell oxidative damage by exciting the activity of a series of antioxidant enzymes. The natural antioxidant peptide screened by the invention has wide application prospects in the fields of foods, medicines, cosmetics and the like, and an efficient way is provided for development of horse milk whey protein source functional polypeptide products.

The invention relates to a weight-losing enzyme and a preparation method thereof, and belongs to the technical field of biology, and the weight-losing enzyme comprises a fruit enzyme, a vegetable enzyme, a seed enzyme and a lotus leaf extract; the fruit enzyme is obtained by performing enzymolysis on mixed fruit pulp of apples, lemons, grapefruits and haws through pectinase, performing enzymolysis through pepsase and performing co-fermentation through bifidobacterium longum and lactobacillus acidophilus; the vegetable enzyme is obtained by performing enzymolysis on mixed vegetable pulp of wax gourd pulp, celery and spinach through pectinase, performing enzymolysis through pepsin and performing fermentation through lactobacillus plantarum and bifidobacterium adolescentis; the seed enzyme is obtained by carrying out trypsin enzymolysis on mixed powder of semen raphani and phaseolus calcaratus, then carrying out nattokinase enzymolysis and then fermenting with bifidobacterium breve; the lotus leaf extract is obtained by sequentially carrying out enzymolysis on lotus leaves through hemicellulase, snail protease and nattokinase. All the components are matched for use, so that the weight-losing food has the effects of promoting digestion, inhibiting fat absorption, regulating intestinal flora, promoting metabolism and the like, and has a good weight-losing effect.

The invention discloses a method for promoting dissolution of eggshell membrane protein and preparing chelated calcium through high-pressure crushing. Comprising the following steps: separating and drying eggshells and eggshell membranes of egg shells, and respectively carrying out superfine grinding to obtain eggshell powder and eggshell membrane powder; adding water into the eggshell membrane powder, carrying out high-pressure homogenization, and centrifuging to obtain an eggshell membrane solution; adding eggshell powder into the eggshell membrane solution, adjusting the pH value to 1-3, and adding pepsase for reaction; after the reaction, adjusting the pH value of the eggshell membrane solution to 6.5-7.5, and adding trypsin for reaction; and after the reaction, inactivating the enzyme, centrifuging to take a supernatant, adding absolute ethyl alcohol into the supernatant for alcohol precipitation, and centrifuging to obtain a precipitate, namely the chelated calcium. The technical problem that the eggshell membrane protein is difficult to dissolve out is solved, and a new way is provided for industrial extraction of the eggshell membrane soluble protein.

The invention belongs to the technical field of deep processing of agricultural products, and provides royal jelly protein zymolyte with melanin inhibition activity and preparation and application of the royal jelly protein zymolyte. Performing enzymolysis on the soluble royal jelly protein solution with pepsin to obtain enzymatic hydrolysate; and carrying out ultrafiltration separation on the enzymatic hydrolysate to obtain a polypeptide solution with the molecular weight of less than 3KDa, namely royal jelly protein hydrolysate. The royal jelly is used as a raw material, the royal jelly protein hydrolysate with low molecular weight is prepared by extracting royal jelly protein and utilizing a protease enzymolysis technology and an ultrafiltration separation technology, and the royal jelly protein hydrolysate has good melanogenesis inhibition activity and can reduce generation of mouse melanoma cells and zebra fish melanin. The inhibitor is derived from natural food royal jelly, is green and safe, is controllable in conditions in the preparation process, is convenient to extract, does not need artificial synthesis, and is expected to be applied to food, medicines or cosmetics with a whitening effect.

The invention relates to an oral mucosa repairing medicine and a preparation method thereof, and belongs to the technical field of medicines, the medicine comprises barnacle peptide, salivary lactobacillus, resveratrol, a biphasic adhesion matrix, hydroxyapatite, vitamin B family and other components. The preparation method comprises the following steps: sequentially carrying out enzymolysis on barnacle gooseneck by pepsin and lumbrukinase to obtain barnacle peptide. The double-phase adhesion matrix comprises a water-phase matrix, an oil-phase matrix and lecithin; the water-phase matrix contains a chondroitin sulfate-chitosan quaternary ammonium salt compound, sodium alginate and other components; the oil-phase matrix comprises sesame oil, beeswax, a polylactic acid-glycolic acid copolymer and the like. According to the invention, barnacle peptide and salivary lactobacillus are prepared by adopting a special method and are matched with resveratrol for use, so that multi-target and multi-path promotion of oral mucosa repair can be realized; the chondroitin sulfate-chitosan quaternary ammonium salt compound is prepared through electrostatic and physical embedding, the chondroitin sulfate-chitosan quaternary ammonium salt compound is matched with other components to prepare the biphasic adhesion matrix, the biocompatibility is good, the adhesion is high, and the action time of a sustained-release drug is well prolonged.

The invention discloses a traditional Chinese medicine composition with the effects of benefiting qi, nourishing blood, invigorating the spleen and tonifying the kidney and a preparation method of the traditional Chinese medicine composition. The traditional Chinese medicine composition is prepared from the following raw materials in parts by weight: cistanche, ginseng, American ginseng, astragalus membranaceus, medlar, rhizoma polygonati, oyster peptide, angelica sinensis, radix rehmanniae preparata, donkey-hide gelatin, fructus amomi, pericarpium citri reticulatae, hawthorn, folium cortex eucommiae, radix puerariae, liquorice and the like. The preparation method comprises the following steps: respectively crushing the medicinal materials, dissolving the colla corii asini, mixing, adding water, granulating and the like. The composition can be prepared into various dosage forms such as granules, capsules, tablets, oral liquid and the like. Experiments show that the traditional Chinese medicine composition can effectively improve the symptoms of deficiency of qi and blood (increasing erythrocyte count and hemoglobin content), weakness of spleen and stomach (increasing body weight and improving pepsin activity) and kidney deficiency (reducing creatinine and urea nitrogen content and improving SOD activity), and acute toxicity experiments show that the toxicity is slightly reversible under high dosage, and the safety is good under therapeutic dosage. The traditional Chinese medicine composition has potential application value in the aspect of preparing medicines for benefiting qi, nourishing blood, invigorating spleen and tonifying kidney.

The invention relates to the field of biological medicine, and provides a preparation method of a fermentation product containing giant salamander peptide, which comprises the steps of stepped enzymolysis pretreatment, staged inoculated fermentation, synergistic enzymolysis and molecular weight grading purification. The method comprises the following steps: firstly, carrying out staged enzymolysis on giant salamander tissues by utilizing pepsin, trypsin and flavourzyme to obtain a primary peptide solution; then, bacillus subtilis, lactobacillus plantarum and bifidobacterium are adopted for directional fermentation, and flora metabolism is optimized through dissolved oxygen control and pH automatic regulation. Then, compound protease is added for secondary enzymolysis, so that the yield of the small molecule peptide is increased. And finally, carrying out ultrafiltration and nanofiltration graded purification, vacuum concentration, freeze drying and gamma-ray sterilization to obtain the micromolecular giant salamander peptide. The molecular weight of the obtained product is mainly distributed within 0.5-5 kDa (lt), and the proportion of 3 kDa is larger than or equal to 80%), the DPPH free radical scavenging rate is larger than or equal to 85%, the ABTS < + > scavenging rate is larger than or equal to 80%, and the obvious anti-oxidation and auxiliary liver protection effects are achieved.

The invention discloses camel milk polypeptide with xanthine oxidase inhibitory activity and application thereof.The camel milk polypeptide is prepared by taking fresh camel milk as a raw material, conducting low-temperature centrifugation to remove fat, conducting triple enzymolysis through papain, pepsin and trypsin to obtain enzymatic hydrolysate, enabling the enzymatic hydrolysate to pass through an ultrafiltration membrane (the molecular weight cutoff is 10 kDa) to obtain filtrate, and conducting freeze-drying to obtain the camel milk polypeptide. The compound has xanthine oxidase inhibitory activity. The invention also discloses a small molecule polypeptide with xanthine oxidase inhibitory activity. The filtered solution is screened and combined with polypeptides by adopting a xanthine oxidase affinity ultrafiltration method, the activity of the polypeptides is verified through molecular docking and in-vitro enzyme inhibition, four small-molecule polypeptides with xanthine oxidase inhibitory activity are obtained, the sequence of the small-molecule polypeptides is shown as any one of SEQ ID NO.1-4, and the small-molecule polypeptides can be used for preparing drugs with the effect of inhibiting the uric acid level.

The invention discloses a polypeptide with ACE inhibitory activity and application thereof, and relates to the technical field of biology. The amino acid sequence of the polypeptide is as shown in SEQ ID NO. 1. The invention further provides application of the polypeptide in preparation of antihypertensive drugs, products beneficial to maintaining the healthy level of blood pressure and angiotensin converting enzyme inhibitors. The ACE inhibitory peptide in tuna blood is efficiently screened through technologies of pepsin and pancreatin enzymolysis, ultrafiltration, liquid chromatography-tandem mass spectrum sequence identification and the like, and the polypeptide with the amino acid sequence being YPWTQR is finally obtained through screening. The polypeptide has good ACE inhibition activity, and the IC50 value of the polypeptide to ACE can reach 46.29 [mu] mol / L. The polypeptide has the potential of being developed into antihypertensive drugs and products beneficial to maintaining the health level of blood pressure, and has high market application value.

The invention relates to a probiotic agent capable of resisting helicobacter pylori infection and application of the probiotic agent. The bacterial strains in the probiotic agent capable of resisting helicobacter pylori infection are composed of a Bifidobacterium animalis subsp. Lactis (Bifidobacterium animalis subsp. Lactis). Lactis BLa80 bacterial strain and a Lactobacillus acidophilus LA18 bacterial strain. The invention further relates to a preparation method of the probiotic agent capable of resisting helicobacter pylori infection and application of the probiotic agent capable of resisting helicobacter pylori infection. The two strains can cooperate with each other and promote each other, and have a synergistic effect in the aspect of resisting helicobacter pylori infection, specifically, the level of an Hp-IgG antibody and the level of endotoxin of a mouse infected with helicobacter pylori are remarkably reduced; the levels of serum inflammatory factors such as IL-17A, IL-10, IL-23, IFN-beta and IFN-gamma of mice infected with helicobacter pylori are regulated, and inflammatory response caused by helicobacter pylori infection is inhibited; the activity of pepsin, the activity of cellulase and the activity of alpha-amylase are obviously improved, so that the digestive ability of the stomach is enhanced.

The invention relates to the field of polypeptides, in particular to a red camellia polypeptide as well as a preparation method and application thereof. Red camellia is used as a raw material, high-pressure homogenization wall breaking and pepsase enzymolysis are performed, and separation and purification are performed to obtain the red camellia polypeptide with repairing, moisturizing, oxidation resisting and nourishing functions. The polypeptide prepared by the invention is more efficient, safer and more environment-friendly, and has a wide application prospect in the fields of cosmetics, functional foods and biological medicines.

The invention belongs to the technical field of marine biological medicines, and relates to a hippocampus polypeptide for improving cognitive impairment of Alzheimer's disease and a preparation method and application thereof.The preparation method comprises the steps that hippocampus powder is dissolved in water, the pH value is adjusted to 1.8-2.5, pepsin is added for oscillation incubation for 2 hours, and then high-temperature heating is conducted to inactivate enzyme; adjusting the pH value to 7.3-8.0, adding chymotrypsin to form a compound enzyme enzymolysis combination, oscillating and incubating for 2 hours, and heating at high temperature to inactivate the enzyme; centrifuging the solution, collecting enzymatic hydrolysate, and filtering the obtained hippocampus crude polypeptide through an ultrafiltration membrane to obtain molecular weight lt; the hippocampus polypeptide is subjected to vacuum freeze drying and preservation. The hippocampus polypeptide extracted and prepared from hippocampus japonicus by adopting a biological enzymolysis method has excellent APP inhibitory activity, can remarkably improve dysmnesia, and can be used for developing related functional foods or medicines for treating Alzheimer's disease.

The invention discloses a casein peptide-containing composition capable of improving sleep as well as a preparation method and application of the casein peptide-containing composition. The casein peptide-containing composition comprises the following components: casein peptide nanoparticles which are prepared by an ultrasonic nanocrystallization technology; the multi-layer micro-capsule coating comprises a double-layer structure formed by natural polysaccharide and a lipid compound, so that the stability of casein peptide in gastrointestinal tracts is improved; an enzyme inhibitor for temporarily inhibiting the activity of pepsin to enhance the bioavailability of casein peptide; according to the casein peptide sleep-aiding composition, through the comprehensive technical design of multi-layer micro-capsule enveloping, nanocrystallization and enzyme inhibitor sheet layers, the stability, the bioavailability and the sleep-aiding effect of the casein peptide sleep-aiding composition are remarkably improved, and the casein peptide sleep-aiding composition shows superiority in the aspects of user experience and production feasibility.

The invention discloses a bone-strengthening lactoprotein extract as well as a preparation method and application thereof, and belongs to the technical field of deep processing of cow milk. The bone-strengthening milk protein extract contains bone-strengthening active peptide FYPELFR. The preparation method specifically comprises the following steps: (1) pasteurization; (2) separating casein; (3) pepsin hydrolysis; (4) trypsin hydrolysis; (5) purifying and desalting; and (6) concentrating and drying. The bone-strengthening active peptide and the bone-strengthening lactoprotein extract containing the bone-strengthening active peptide can be combined with integrin alpha v beta 1 through hydrophobic interaction and hydrogen bonds, proliferation and differentiation of osteoblasts are promoted by activating a specific signal channel, proliferation of the osteoblasts is promoted, and the bone-strengthening active peptide and the bone-strengthening lactoprotein extract can be used for development of bone-strengthening functional food or drugs and have important significance on deep processing of cow milk.

The invention provides a pepsin detection card and a preparation process thereof, and belongs to the technical field of microbiological detection. The kit comprises a test strip and a card shell, the test strip comprises a nitrocellulose membrane, a sample pad, absorbent paper, a combination pad and a bottom plate. The pepsase detection card is high in sensitivity, can accurately capture pepsase with extremely low concentration in a sample, effectively avoids missed diagnosis, strives for precious time for early intervention, is high in specificity, is only specifically combined with pepsase, is not interfered by other similar proteases or impurities in the sample, and can be used for detecting the pepsase in the sample. In a complex human body biological sample environment, the target pepsin can still be accurately recognized, the specificity reaches 98% or above, false positive results are greatly reduced, and a reliable basis is provided for clinical diagnosis.

The invention relates to a kit for detecting pepsinogen I and a preparation method of the kit, and relates to the technical field of biology. The kit comprises an enzyme marker, a luminous marker, a luminous auxiliary agent and a triggering agent, the enzyme marker comprises an anti-PG I monoclonal antibody marked by horse radish peroxidase; the luminous marker comprises an anti-PG I monoclonal antibody marked by 9, 10-dihydroacridine; the light-emitting auxiliary agent comprises H2O2. According to the present invention, the spatial proximity chemiluminescence analysis method is adopted, and the carrier and the washing process are not required, such that the kit cost is reduced, and the detection time is shortened; the method adopts homogeneous reaction, so that the detection result is more real and credible.

The invention belongs to the technical field of active peptides, and particularly relates to an active peptide capable of improving memory, a brain peptide enzymolysis extract and a preparation method and application of the brain peptide enzymolysis extract. The amino acid sequence of the active peptide is shown as SEQ ID NO.1 Ala-Ala-Val-Pro, and the active peptide can improve sleep and improve memory; on the other hand, the invention provides a preparation method of the brain peptide enzymolysis extract. The preparation process comprises the steps of raw material pretreatment and grinding, microwave treatment and centrifugal separation, protein precipitation and enzymolysis, microwave-assisted enzymolysis and purification and nanofiltration membrane filtration. Pepsase is added in the microwave treatment, and the temperature is not more than 50 DEG C in the enzymolysis process, so that the small molecule peptide keeps relatively high activity; furthermore, carbon dioxide gas is introduced in the microwave treatment for aeration, and the aeration pressure and the pH value are optimized, so that the activity and the yield of the brain peptide enzymolysis extract are further improved.

The invention discloses a preparation method of micromolecular active collagen peptide, which comprises the following steps: (1) cutting fresh leather into fragments, pretreating the leather with a sodium bicarbonate solution, rinsing the leather with deionized water, and refrigerating and storing; (2) mixing papain, bromelain, pancreatin, pepsase, alkaline protease, neutral protease and flavourzyme to obtain a compound enzyme preparation; (3) performing high-pressure steam sterilization on the leather at 110-140 kPa and 120-122 DEG C to obtain leather with the hydrolysis degree of 75-85%, then adding distilled water into the leather to obtain mucilage, then adding a compound enzyme preparation into the mucilage, reacting for 5.5-6.5 hours at the pH of 6.8-7.2 and the temperature of 50-55 DEG C, and then performing enzyme inactivation at the temperature of 85-95 DEG C; and (4) after the reaction system is cooled to room temperature, purifying and centrifuging the reaction system, and taking clarified supernate, thereby obtaining the product. Different animal skins are treated, the proportion of peptide fragments with the molecular weight smaller than 1000 Da of the prepared small-molecule active collagen peptide is larger than or equal to 80%, and the hydroxyproline content is larger than 3%.

This invention relates to the field of biocatalysis technology, and more particularly to an aflatoxin oxidase, its preparation method, and its applications. This invention utilizes a self-designed artificial intelligence enzyme design workflow to de novo design a novel aflatoxin oxidase, DnD-AFO. Compared to the traditional wild-type AFO, DnD-AFO exhibits enhanced activity, better thermal stability (its activity is significantly superior to the wild-type after high-temperature granulation), and improved resistance to pepsin and acid. Furthermore, it further enhances the detoxification efficiency against aflatoxin, making it well-suited as a food or feed additive for applications in agriculture and food engineering, among other related industries, demonstrating significant commercial and added value.

This invention relates to the field of chicken gizzard lining processing technology, and particularly to an active polypeptide of chicken gizzard lining, its preparation method, and functional products. The preparation method includes the following steps: mixing chicken gizzard lining powder with water and subjecting it to alkaline heat treatment to form a slurry; sequentially adding Bacillus licheniformis alkaline protease, trypsin, and pepsin to the slurry for three separate hydrolysis processes to obtain a hydrolysate; after enzyme inactivation treatment of the hydrolysate, adding Lactobacillus plantarum for fermentation to obtain a fermentation broth; sterilizing the fermentation broth and then filtering it to obtain a fermentation supernatant; sequentially subjecting the fermentation supernatant to membrane filtration, sterilization, and spray drying to obtain the active polypeptide of chicken gizzard lining. The active polypeptide of chicken gizzard lining prepared by the method of this invention exhibits alcohol dehydrogenase activating activity, AGEs inhibitory activity, albumin denaturation inhibitory activity, lipoxygenase inhibitory activity, pancreatic lipase inhibitory activity, and a beneficial bacteria proliferation promoting effect.

The invention discloses a hydrogel plugging umbrella for gastric perforation and a preparation method thereof. The hydrogel plugging umbrella comprises a plugging part, and fixing parts are integrally formed at the two ends of the plugging part. The excellent plugging effect is achieved through the triple synergistic effect, the space mechanical interlocking effect brought by the double-umbrella-shaped design provides the immediate plugging and continuous self-expansion compaction effect, and physical and chemical adhesion of a tissue-gel interface ensures that under the corrosive gastric juice environment and the dynamic mechanical load, the plugging effect is good, and the plugging effect is good. A safe and lasting gastric perforation sealing effect can still be provided; the caffeic acid modified chitosan component has unique proton adsorption and biomolecule capture characteristics and can effectively block permeation of digestive enzymes such as gastric acid and pepsase, the protection effect not only maintains the activity of endogenous growth factors in a wound microenvironment, but also creates conditions beneficial to tissue regeneration, and the wound healing effect is improved. Therefore, healing and repairing of gastric perforation are remarkably promoted.

The invention discloses a method for digesting an extracellular matrix by an immobilized enzyme and application, and relates to the technical field of biology. The method comprises the following steps: (1) performing decellularization treatment on tissues to obtain an extracellular matrix; (2) dispersing the surface functionalized microspheres in a buffer solution, adding a coupling agent, mixing, and collecting the activated microspheres; (3) dispersing the activated microspheres in a buffer solution containing pepsin, mixing, and collecting immobilized enzyme microspheres; and (4) crushing the extracellular matrix, dispersing the crushed extracellular matrix in a solution, adding the immobilized enzyme microspheres for digestion, and separating and removing the immobilized enzyme microspheres after digestion is completed. According to the method provided by the invention, the enzymolysis of the immobilized enzyme on the extracellular matrix is realized by adopting a proper microsphere particle size and a proper zeta potential. According to the method disclosed by the invention, the residual quantity of free enzyme is relatively small, so that the biological safety of the extracellular matrix material is improved.

The invention discloses a method for extracting and purifying natural active collagen, particularly relates to a method for purifying type I collagen, and belongs to the technical field of collagen production. By adopting a purification scheme of salting-out and ultrafiltration purification liquid change, high-purity and high-activity natural I-type collagen can be successfully obtained, and the problems of low biological activity and low protein purity caused by long collagen purification period and high non-target protein content in the traditional purification technology are solved. The method for purifying the I-type collagen mainly comprises the following steps: S1, carrying out pretreatment on raw materials, carrying out reaction by adopting an enzymolysis technology, and then obtaining I-type collagen enzymatic hydrolysate by adopting a centrifugation method; s2, preliminarily removing soluble impure protein, pepsin and other impurities by using a salting-out process; and S3, redissolving the crude extract, filtering through a polypropylene folded filter element to obtain a raw material solution, purifying the raw material solution through a tangential flow ultrafiltration method, and concentrating to obtain the I-type collagen purified solution.

According to the infant amino acid nutritional rice flour and the preparation method thereof, four proteases including flavourzyme, pepsase, papain and bromelain are provided, and the proteases have very high hydrolytic activity and can fully hydrolyze protein in rice and whole milk powder to form various amino acids and polypeptide fragments, so that the nutritional rice flour is prepared; the rice flour is beneficial to digestion and absorption of infants, does not cause protein allergy, also improves the utilization rate of protein, and also can increase the flavor of the rice flour. Through detection, all 16 amino acids listed in GB5009.124-2016 Measurement of Amino Acid In Food National Standard for Food Safety can be detected in the infant amino acid nutritional rice flour prepared by the method disclosed by the invention; the amino acids are respectively alanine, valine, leucine, isoleucine, phenylalanine, proline, glycine, serine, threonine, tyrosine, methionine, lysine, arginine, histidine, aspartic acid and glutamic acid, the content of the glutamic acid is the highest, and the total amount of the amino acids can reach 10.5-11.2 g / 100g.

The invention provides a pepsinogen II determination kit and a quantitative determination method, the kit comprises a reagent R1 and a reagent R2, the reagent R1 comprises a luminous donor molecule labeled pepsinogen II first antibody and a reaction buffer solution; and the R2 reagent comprises a light-emitting receptor molecule labeled pepsinogen II second antibody and a reaction buffer solution. A double-antibody sandwich structure marked by a luminescent donor and a luminescent receptor respectively is adopted, binding and luminescence can be completed in a liquid phase, solid phase coating and subsequent multi-step washing are not needed, real homogeneous detection and one-step incubation are achieved, the operation process is simplified, the detection time is shortened, and a full-automatic platform is adapted; and an improved buffer system can inhibit non-specific adsorption and reduce heterotropism interference such as RF / HAMA, so that the detection accuracy and repeatability are improved.

The invention discloses a casein-sourced multifunctional peptide, and belongs to the field of food science and nutriology. The casein is subjected to enzymolysis through pepsin, a method combining activity verification and mass spectrum identification is adopted, the novel multifunctional peptide YPE with a clear sequence is screened and verified, the highest ABTS clearance rate of the casein peptide YPE can reach 77.76%, the highest hydroxyl radical clearance rate of the casein peptide YPE can reach 40.18%, and the casein peptide YPE can be used for preparing the novel multifunctional peptide YPE. The inhibition rate of alpha-glucosidase reaches 30.47%, the inhibition rate of escherichia coli is 10.18%, and the limitation of an existing single-function peptide in application is overcome.

The invention aims to realize self-adhesion fixation of a cartilage repair scaffold, and provides a collagen scaffold preparation method capable of controllably removing terminal peptide, which comprises the following steps: S1, cleaning and shearing a collagen raw material to obtain a granular collagen raw material; s2, dehydrating, centrifuging and dispersing the granular collagen material to obtain a dispersed collagen material; s3, performing enzymolysis treatment on the dispersed collagen material to obtain a collagen solution; step S4, preparing a collagen scaffold by adopting a collagen solution, in the step S3, the removal rate of terminal peptides in the collagen solution is controlled to be 60%-80%, and the step S3 comprises the following steps: adding water, glacial acetic acid and pepsase into the dispersed collagen material according to the mass ratio of the dispersed collagen material to the water to the glacial acetic acid to the pepsase being 1: (5-25): (0.3-1.0): (0.05-1.5); keeping the temperature at 4-8 DEG C for 48-120 hours, and stirring for multiple times during the keeping period; and performing low-temperature gradient dialysis at the temperature of 4-8 DEG C to remove enzyme solution residues, thereby obtaining the collagen solution. The invention also provides the collagen scaffold prepared by the method and application of the collagen scaffold.

The invention discloses a tilapia skin DPP-IV inhibitory peptide as well as a preparation method and application thereof, and belongs to the technical field of food-borne active peptide development. The preparation method comprises the following steps: taking tilapia skin as a raw material, extracting gelatin from the tilapia skin through an acid-alkali treatment method, and then performing simulated gastrointestinal digestion on the gelatin by utilizing simulated digestive juice prepared from pepsin, trypsin and chymotrypsin to obtain a digestion product with DPP-IV inhibitory activity; the tilapia skin active peptide with relatively high DPP-IV inhibitory activity is obtained through further ultrafiltration and identification, amino acid sequences of the tilapia skin active peptide are AKVELLK, VPGPMGPMGPR and DGIR respectively, and the three inhibitory peptides have good DPP-IV inhibitory activity and can be used for developing food, health care products or medicines for assisting in regulating blood sugar.

The invention belongs to the technical field of antibodies, and particularly relates to an anti-human pepsinogen I (Pesinogen I, PG I) antibody, an antibody pair and a detection kit. The antibody is a first antibody or a second antibody, amino acid sequences of light chains CDR1-3 of the first antibody are respectively shown as SEQ ID NO.3-5, and amino acid sequences of heavy chains CDR1-3 of the first antibody are respectively shown as SEQ ID NO.8-10; the amino acid sequences of light chains CDR1-3 of the second antibody are respectively as shown in SEQ ID NO.13-15, and the amino acid sequences of heavy chains CDR1-3 of the second antibody are respectively as shown in SEQ ID NO.18-20. The antibody and the antibody pair disclosed by the invention have specific recognition and binding capacity and relatively high affinity and detection sensitivity to human PG I protein, and a reliable antibody tool and a detection means are provided for stably detecting trace-level human PG I protein.

The invention discloses a uric acid reducing polypeptide, the polypeptide is derived from a peptide fragment, the'bindingerge 'value of the peptide fragment in molecular docking with xanthine oxidase is less than-1.5 kcal / mol, and the peptide fragment, in molecular docking with the xanthine oxidase, of the polypeptide is derived from a Peptide Ranker biological activity score gt; and 0.7 of a polypeptide. The uric acid reducing polypeptide is obtained by screening natto powder subjected to pepsin enzymolysis, natto powder enzymatic hydrolysate obtained through enzymolysis has the activity of inhibiting xanthine oxidase, the screened uric acid reducing polypeptide can be developed into a uric acid reducing medicine, and active ingredients are added into functional food and health food, so that the uric acid reducing polypeptide has a good application prospect. Good market prospects are realized in medicine and food industries.