279 results about "Pepsin" patented technology

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 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 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 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.

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 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.

The invention relates to the technical field of test strips, in particular to a human saliva pepsin fluorescence immunochromatography test strip and a preparation method thereof.The human saliva pepsin fluorescence immunochromatography test strip is characterized in that a sample pad, a marking pad, a nitrocellulose membrane and a water absorption pad are pasted to the upper surface of a PVC plate, and the surface of the marking pad is sprayed with a pepsin marked antibody compound containing fluorescent microsphere marks; the fluorescence immunochromatography test strip provided by the invention can be used for specific detection of human saliva pepsin antigen, has a wide linear range, high sensitivity and high precision, can maintain the test value of the test strip to be basically unchanged for 14 days through accelerated destruction at 37 DEG C, shows good stability, and can be applied to detection of human saliva pepsin antigen. Meanwhile, the test strip is not interfered by amylase and lipase and has relatively high specificity, in addition, a method for detecting human saliva pepsin by adopting a fluorescence immunochromatography method has the advantages of operation detection, less time consumption, small matched equipment, low cost and the like, can meet the requirement of instant detection and has relatively high application value.

The invention discloses a kit and a method for detecting pepsin based on polypeptide, and belongs to the technical field of proteomics. The amino acid sequence of the polypeptide is as shown in SEQ ID No. 1. The polypeptide is obtained based on enzymolysis of pepsinogen PGA4 and screening, the polypeptide and isotope labeled polypeptide are utilized to establish a standard curve, a biological sample is further subjected to enzymolysis to obtain a peptide fragment sample, and pepsin in the biological sample can be quantified by detecting the content of the polypeptide in the peptide fragment sample. By utilizing the method disclosed by the invention, the pepsin in the biological sample can be rapidly quantified, so that pathological reflux and physiological reflux are diagnosed and distinguished, and the accuracy rate is high.

The invention relates to a chemiluminescence kit for detecting pepsinogen II. The kit comprises an enzyme marker, a luminescent substrate solution and an anti-interference buffer system, the anti-interference buffer system comprises a nonionic surfactant, animal-derived IgG (immunoglobulin G), an antioxidant and catalase; the chemiluminescence kit also comprises a PG II calibration product and a PG II quality control product. The core active component of the enzyme marker is beta-galactosidase. The enzyme marker further comprises an anti-PG II monoclonal antibody marked by beta-galactosidase, bovine serum albumin, trehalose, cane sugar, MgCl2. 6H2O, sodium chloride, Proclin300 and a phosphate buffer solution. According to the kit, a brand-new anti-interference buffer system is introduced on the basis of a spatial proximity chemiluminescence analysis method, so that the resistance to clinically common interferents (such as hemolysis, lipemia, jaundice and heterotropism antibodies) is remarkably improved, and the detection result is more accurate and reliable.

The invention discloses a preparation method of a fructus cannabis protein peptide product with effects of resisting fatigue and improving exercise ability, which comprises the following steps: performing preliminary crushing, ultralow-temperature freezing micro-crushing and low-temperature continuous phase-change extraction degreasing on fructus cannabis, performing step-by-step hydrolysis by using polysaccharase and 2.4 L bacterial protease to extract fructus cannabis protein, performing low-temperature salting-out, and performing freeze-drying to obtain the fructus cannabis protein peptide product with the effects of resisting fatigue and improving exercise ability. The fructus cannabis protein peptide powder is prepared through low-temperature ultrasonic dissolution promotion, high-pressure micro-jet homogenization, compound enzyme C hydrolysis, 1% pepsase, high-temperature enzyme deactivation, chlorophyll removal through counter-current extraction, hydrogen peroxide decoloration, ultralow-temperature instantaneous concentration, low-temperature vacuum belt type drying and low-temperature ultrahigh-pressure sterilization. The fructus cannabis protein peptide prepared by the invention has the following remarkable effects: 1, the exercise ability is remarkably improved, the accumulation of lactic acid and urea nitrogen is reduced, the exhaustion time is prolonged, and the physical and mental fatigue is relieved; 2, the content of hepatic glycogen and muscle glycogen is obviously increased, the energy reserve of the body is increased, the explosive power and the reactivity are improved, and the athletic performance is improved; and 3, the antioxidant level of the body is improved, and fatigue and immune recovery after exercise are promoted.

The invention relates to the technical field of colla corii asini peptide preparation, in particular to a preparation method of colla corii asini peptide. The preparation method comprises the following steps: step 1, unhairing and degreasing fresh donkey hide, dicing, blanching and cleaning to obtain blocky donkey hide; step 2, adding the blocky donkey hide into water for ultrasonic treatment, then cooking, filtering and collecting filtrate 1; and step 3, adding a compound enzyme into the filtrate 1, carrying out ultrasonic treatment, sequentially carrying out enzymolysis, enzyme deactivation and centrifugal filtration, carrying out debitterizing, decolorizing and degreasing treatment on the obtained filtrate 2, carrying out ultrafiltration, and carrying out spray drying to obtain the colla corii asini peptide, the compound enzyme is a mixture of alkaline protease, neutral protease, pepsase and papain in a mass ratio of 3: 1: 2: 1. According to the method, the donkey-hide gelatin peptide is prepared from the fresh donkey hide, the production cost is reduced, and the donkey-hide gelatin peptide with the molecular weight smaller than 1000 Daltons in the donkey-hide gelatin peptide prepared through the method is high in proportion and can be easily absorbed and utilized by the human body.

The invention provides chickpea protein peptide as well as a preparation method and application thereof. The preparation method of the chickpea protein peptide provided by the invention comprises the following steps: sequentially carrying out enzymolysis on chickpea protein isolate by using neutral protease, pepsin and pancreatin; after the enzymolysis is finished, performing ultrafiltration on an enzymolysis product by using an ultrafiltration membrane with the interception amount of 3kDa, and collecting components with the molecular weight of less than 3kDa; and finally, carrying out gel chromatography on the component, and collecting the corresponding component to obtain the chickpea protein peptide. The chickpea protein peptide prepared by the method has inhibitory activity on DPP-IV, alpha-glucosidase and alpha-amylase, can effectively inhibit the activity of Caco-2 cell sucrase, maltase and DPP-IV, and has a certain inhibitory effect on glucose transport; therefore, the chickpea protein peptide provided by the invention has good hypoglycemic activity, and a new thought is provided for development of food-borne functional protein peptides.

The invention discloses a quenching type supramolecular fluorescent probe for pepsin detection as well as a preparation method and application of the quenching type supramolecular fluorescent probe. The quenching type supramolecular fluorescent probe is obtained by virtue of supramolecular interaction of a luminous monomer and a protein molecule; wherein the protein molecule is selected from any one or a combination of more of human serum albumin, bovine serum albumin, casein, hemoglobin and collagen; the luminous monomer comprises an alpha-cyano styrene derivative. The quenching type supramolecular fluorescent probe is easy to synthesize, has good water solubility, can be used as a quenching type fluorescent probe of pepsin, has good selectivity and anti-interference capability, and can well meet the requirements of high sensitivity and accurate detection of pepsin.

The invention provides a PGI monoclonal antibody combination for pepsinogen I detection and application thereof, the PGI monoclonal antibody combination for pepsinogen I detection comprises a first antibody and a second antibody, the first antibody comprises a first light chain variable region and a first heavy chain variable region, and the second antibody comprises a second light chain variable region and a second heavy chain variable region. The second antibody comprises a second light chain variable region and a second heavy chain variable region; wherein the amino acid sequence of the first light chain variable region comprises VL-CDR1-3 as shown in SEQ ID NO: 1-3; the amino acid sequence of the first heavy chain variable region comprises VH-CDR1-3 as shown in SEQ ID NO: 4-6; the amino acid sequence of the second light chain variable region comprises VL-CDR1-3 as shown in SEQ ID NO: 7-9; and the amino acid sequence of the second heavy chain variable region comprises VH-CDR1-3 as shown in SEQ ID NO: 10-12. The monoclonal antibody combination can improve the sensitivity and accuracy of in-vitro detection.