154 results about "Aminopeptidase" patented technology

A compound of formula (I) or a pharmaceutically acceptable salt or hydrate thereof wherein X-Y is -NHSO2- or -SO2NH-; R1 is H, CN or alkyl; R2 is selected from COOH and a tetrazolyl group; R3 is selected from H, Cl and alkyl; R4 is selected from H and halo; R5 is selected from H, alkyl, haloalkyl, SO2-alkyl, Cl, alkoxy, OH, CN, hydroxyalkyl, alkylthio, heteroaryl, cycloalkyl, heterocycloalkyl and haloalkoxy; R6 is H; R7 is selected from H, CN, haloalkyl, halo, SO2-alkyl, optionally substituted heteroaryl, SO2NR14R15, CONR10R11 and alkyl; R8 is selected from H, alkyl, haloalkyl and halo; R9 is H or halo; and R10, R11, R12, R14, and R15 are H or alkyl; R13 is selected from alkyl, halo, alkoxy, CN, haloalkyl and OH; and m is 0-3. The compounds of formula (I) modulate ERAP1 (endoplasmic reticulum aminopeptidase 1) and are for use in treating proliferative, immune or inflammatory disorders, particularly cancer or leukemia. The compounds of formula (I) stimulate a neo-antigen directed immune response in the subject. A method for producing an antigen-presenting cell which presents a neo-antigen using compounds of formula (I) is disclosed. An immunogenic composition comprising an antigen-presenting cell is also disclosed. Exemplified compounds include 4-cyclopropyl-3-(N-(2-(morpholin-3-yl)-5-(trifluoromethyl)phenyl)sulfamoyl)benzoic acid.

The invention relates to the technical field of enzyme engineering, in particular to an aminopeptidase mutant, a preparation method of the aminopeptidase mutant and application of the aminopeptidase mutant to preparation of L-carnosine. The aminopeptidase mutant is obtained by mutating wild type aminopeptidase and can be used for preparing the L-carnosine through reverse hydrolysis of beta-alanine methyl ester and L-histidine. The L-carnosine produced by using the aminopeptidase mutant disclosed by the invention has the following advantages: 1, the conversion rate is greater than or equal to 95%, the conversion time is short, and relatively cheap alanine methyl ester can be used as a raw material to catalytically prepare the L-carnosine; 2, the production process is simple, the reaction conditions are mild, and the green chemistry concept is met;

The invention relates to the field of microorganisms, and discloses an Aspergillus oryzae strain and application thereof.The Aspergillus oryzae can produce protease, aminopeptidase, glutaminase, cellulase, amylase and pectinase at high yield, and when the Aspergillus oryzae is applied to soy sauce brewing, the utilization rate of raw materials can be increased, the content of amino acid in soy sauce can be increased, and the flavor of the soy sauce can be increased.

The invention relates to the technical field of microorganisms, in particular to an Aspergillus oryzae ZA307 strain and application of the Aspergillus oryzae ZA307 strain. The aspergillus oryzae ZA307 high-yield protease and aminopeptidase provided by the invention cooperate with aspergillus oryzae Huniang 3.042 for starter propagation, so that the activity of the protease, aminopeptidase, saccharifying enzyme and amylase of a starter material can be remarkably improved, and furthermore, the content of ammonia nitrogen and total nitrogen and the variety and content of volatile flavor substances in a product are remarkably improved. The soy sauce or soybean paste prepared and fermented by double-strain starter propagation is obviously improved in the aspects of sauce fragrance, ester fragrance, delicate flavor and harmonious taste, and the quality of the product is comprehensively improved.

The invention discloses aminopeptidase for synthesizing L-carnosine and an application of the aminopeptidase. The amino acid sequence of the aminopeptidase is as shown in SEQ ID NO: 3 or 5. The aminopeptidase disclosed by the invention can catalyze L-histidine with high selectivity to synthesize L-carnosine in the presence of beta-alanine methyl ester, and has relatively high enzyme activity and industrial application value.

The invention provides collagen tripeptide liquid with moisturizing and anti-photoaging effects and a preparation method thereof, and relates to the technical field of bioactive peptides.The preparation method comprises the steps that pretreatment and first-time enzymolysis are conducted, specifically, pretreated fish skin and water are mixed, the pH value is adjusted, compound protease is added for enzymolysis, and first enzymatic hydrolysate is obtained; second-time enzymolysis: adjusting the pH value of the first enzymatic hydrolysate to 6.0-7.5, adding neutral protease for enzymolysis, and then adding aminopeptidase for enzymolysis for 20-40 minutes to obtain second enzymatic hydrolysate; and performing enzyme deactivation, decoloration, separation and purification to obtain collagen tripeptide liquid. Wherein the content of collagen tripeptide, the content of glycine-proline-hydroxyproline and the content of hydroxyproline are high, and good moisturizing and anti-photoaging effects are achieved.

The invention discloses a compound preparation, the compound preparation contains bacillus subtilis and lactobacillus casei, the bacillus subtilis is bacillus subtilis, the strain number of the bacillus subtilis is YB-10, the bacillus subtilis is preserved in the China General Microbiological Culture Collection Center (CGMCC), the preservation number is CGMCC NO.21103, and the lactobacillus casei is preserved in the China General Microbiological Culture Collection Center (CGMCC). The lactobacillus casei is lactobacillus casei, the strain number of the lactobacillus casei is TD01, the lactobacillus casei is preserved in the China Center for Type Culture Collection, and the preservation number of the lactobacillus casei is CCTCC NO: M 2022104. The bacillus subtilis YB-10 disclosed by the invention has a very high degradation rate on antigen protein in soybean meal, and can accumulate high-content acid soluble protein under the condition of solid state fermentation; the lactobacillus casei TD01 disclosed by the invention has a very good degradation effect on stachyose and raffinose in soybean meal; an intracellular metabolite obtained after autolysis of the lactobacillus casei TD01 cell has relatively high aminopeptidase activity, and bitter taste caused by accumulation of high acid soluble protein can be effectively removed.

The invention relates to a process for producing three recombinases capable of hydrolyzing organophosphorus, carbamate and pyrethroid insecticides, and preparations containing these enzymes. The present invention provides recombinant plasmid DNA vectors in which the protein secretion system has been modified to improve the ability of recombinant proteins to secrete into the space around the plasmid or culture medium. A nucleotide sequence for coding a PelB (butyric acid lyase B) signal sequence is deleted and substituted by a nucleotide sequence for coding a LamB (maltodextrin or phage lambda receptor) signal sequence, so that the secretion efficiency of the recombinant protein is higher. The invention discloses three recombinant plasmid DNA (deoxyribonucleic acid) vectors which are constructed by utilizing the improved plasmid DNA vectors and are used for expressing recombinant proteins. The recombinant protein comprises (a) a recombinant organophosphate hydrolase having at least 80% sequence identity with the amino acid sequence of methyl parathion hydrolase (MPH) (Protein Database (PDB) ID: 1P9E) as shown in SEQ ID NO: 1, wherein the recombinant organophosphate hydrolase has hydrolytic activity on organophosphate insecticides; (b) a recombinant carbamate hydrolase having at least 80% sequence identity with the amino acid sequence of L-aminopeptidase-D-Ala-esterase / amidase (aryl amidase) (MAH) (PDB ID: 1B65), as shown in SEQ ID NO: 2, wherein the recombinant carbamate hydrolase has hydrolytic activity on carbamate insecticides; and (c) a recombinant pyrethroid hydrolase having at least 80% sequence identity with the amino acid sequence of the pyrethroid hydrolytic carboxylesterase (EstA) (PDB ID: 4CCY) as shown in SEQ ID NO: 3, wherein the recombinant pyrethroid hydrolase has hydrolytic activity on a pyrethroid insecticide. The embodiment of the invention further provides three recombinant bacterial strains, an escherichia coli strain BL21 (DE3) is used as a host cell, and each recombinant plasmid DNA vector is used for transformation. The invention also discloses culture conditions of the recombinant strain, wherein the culture conditions comprise culture medium composition, induction conditions and enzyme harvesting and enzyme activity detection methods. In addition, the embodiment of the invention also provides a preparation which contains the three recombinases as functional components.

The invention relates to the technical field of polypeptide biosynthesis, in particular to a method for biosynthesizing acetyl tetrapeptide-5, a composition containing the acetyl tetrapeptide-5 and application of the composition. According to the method, low-cost natural amino acid is used as a substrate, specific aminopeptidase or a mutant thereof is used as a biocatalyst, amino acid ligase and polyphosphatase are combined, and acetyl tetrapeptide-5 can be efficiently synthesized through a one-step enzymatic reaction. Compared with a traditional chemical synthesis method, the method has the advantages of low raw material cost, no use of an organic solvent, mild reaction conditions, high regioselectivity, environmental friendliness, low production cost and the like. The invention also provides a composition containing acetyl tetrapeptide-5 and dipeptide-15, the inhibition effect of the composition on grease secretion is obviously better than that of a single component, and the composition has a synergistic oil control effect under a specific ratio.

The invention relates to a method for reducing the anaphylaxis of natural latex by multi-enzyme cascade catalysis of rubber protein. The invention relates to the technical field of catalysis of rubber protein hydrolysis, in particular to a method for reducing the anaphylaxis of natural latex by thoroughly hydrolyzing rubber protein through multi-enzyme cascade catalysis. The method for reducing the anaphylaxis of the natural latex by catalyzing the rubber protein through the synergistic effect of multiple enzymes from the perspective of industrial production comprises the following steps: adding an enzyme A and an enzyme B into the natural latex for reaction so as to reduce the anaphylaxis of the natural latex, the enzyme A is alkaline protease; and the B enzyme is at least one of aminopeptidase, carboxypeptidase B, carboxypeptidase A and carboxypeptidase Y. According to the method disclosed by the invention, the enzyme A-endopeptidase and the enzyme B-exopeptidase are subjected to multi-enzyme-stage combined treatment and concerted catalysis, so that the enzyme A-endopeptidase and the enzyme B-exopeptidase are completely hydrolyzed or are completely hydrolyzed into more amino acid substances and short-chain peptides (oligopeptides) as far as possible, and the amino acid substances and the short-chain peptides (oligopeptides) are retained in latex. Protein is highly hydrolyzed into amino acid with higher safety, so that the possibility of I-type anaphylactic reaction caused by protein allergens is greatly reduced or even eliminated.

The invention belongs to the technical field of food, and provides a special enzyme composition for infant soybean milk powder and soybean milk powder thereof. A three-stage directional enzymolysis technology is adopted, the three-stage directional enzymolysis technology comprises glutamine transaminase deamidation pretreatment, bacillus subtilis protease-trypsin-papain first-stage hydrolysis and aminopeptidase-phytase-beta-glucosidase second-stage hydrolysis, and conductivity control, carbon dioxide ventilation in-situ complexation and spray drying processes are combined. The free amino nitrogen of the product is increased by more than or equal to 20%, the proportion of 200-1500Da peptide fragments is more than or equal to 70%, the median particle size is 50-180 microns, the water activity is less than or equal to 0.30, the instant dissolving time is less than or equal to 30 seconds at 25 DEG C under the water hardness of 15-200ppm, the settling rate is less than or equal to 3% after standing for 30 minutes, and the zeta potential is-10 to-25mV. The palatability contradiction between deep hydrolysis and bitterness inhibition of the bean-based infant formula powder, the brewing contradiction between high-calcium reinforcement and instant stability and the process controllability contradiction between three-stage enzymolysis and ionic strength accumulation are effectively solved, and the bean-based infant formula powder has wide application value in the fields of bean-based infant formula food and vegetable protein nutritional products.

The invention relates to the technical field of microbial mutation breeding and fermentation, and discloses marine-derived halophilic staphylococcus nepalensis with high yield of aminopeptidase and application of the marine-derived halophilic staphylococcus nepalensis. A strain with high yield of aminopeptidase is screened out from traditional fermented shrimp paste to serve as an original strain, ARTP mutagenesis is carried out, the mutant halophilic bacterium with high safety performance, good fermentation performance and genetic stability and high yield of aminopeptidase is obtained through screening, the mutant halophilic bacterium is named as Staphylococcus nepalensis T-13 and is named as SN-T13 for short, and the mutant halophilic bacterium is preserved in China Center for Type Culture Collection (CCTCC) and is named as SN-T13 for short, and the mutant halophilic bacterium is named as SN-T13 for high yield of aminopeptidase and is named as SN-T13 for high yield of aminopeptidase and is named as SN-T13 for high yield of aminopeptidase. The preservation number of the strain is CCTCC NO: M 20231090, and the strain can be used for industrial fermentation of aquatic products.

The invention relates to a composition for bone repair and growth and a preparation method thereof, and belongs to the technical field of medicines, the composition comprises a glue layer extracted peptide in sandjellyfish and a tabasheer-grifola frondosa composite bacterial peptide; the extract peptide of the glue layer in the sand jellyfish contains a product between 500Da and 2000Da, wherein the product is obtained by sequentially carrying out reaction on the glue layer in the sand jellyfish through lumbrukinase, serrapeptase and glutamine transaminase; the tabasheer-grifola frondosa composite bacterial peptide contains a product between 500Da and 2000Da, which is obtained by performing common enzymolysis on tabasheer mushrooms and grifola frondosa mushrooms through cellulase and chitinase, then performing common enzymolysis on the tabasheer mushrooms and the grifola frondosa mushrooms through nattokinase and serrapeptase and finally performing common reaction on aminopeptidase and glutamine transaminase. According to the invention, a special method is adopted to prepare the glue layer extracted peptide and the tabasheer-grifola frondosa compound bacterium peptide in the sandfish, and the glue layer extracted peptide and the tabasheer-grifola frondosa compound bacterium peptide are matched for use to achieve good biological activity, stability and absorption and utilization rate, so that the defects of the existing skeleton repair and growth medicines are overcome, and the repair and growth of skeletons are effectively promoted.

The present invention addresses the problem of providing an enzyme agent containing a novel aminopeptidase that exhibits substrate specificity different from that of conventional aminopeptidase. The present invention relates to an enzyme agent comprising, as an active ingredient, aminopeptidase comprising the amino acid sequence of SEQ ID NO: 1 or SEQ ID NO: 8 or an amino acid sequence equivalent thereto. Furthermore, the present invention relates to an enzyme agent which contains, as an active ingredient, an aminopeptidase that is derived from Aspergillus nidulans or Aspergillus oryzae and has the following physicochemical properties. (1) the optimum temperature is about 50 DEG C; and (2) the optimum pH is about 7-8. And (3) primer specificity: the primer has the highest specificity on L-alanine residues or L-lysine residues.

The invention provides a method for efficiently preparing active polypeptide by fermenting rapeseed dregs, which comprises the following steps: pretreatment: crushing rapeseed dregs, adding 3-5% of reducing sugar, humidifying and sterilizing; performing mixed bacteria segmented fermentation: inoculating a composite strain consisting of bacillus licheniformis SWJS33 with high yield of aminopeptidase, aspergillus oryzae and lactobacillus plantarum, and fermenting at 30 DEG C or 37 DEG C for 72-84 hours; ultrasonic wall breaking: adding water after fermentation, uniformly mixing, carrying out ultrasonic treatment for 20-30 minutes under the power of 120-200W, and breaking thalli to release intracellular enzyme; enzymolysis: carrying out enzymolysis for 4-6 hours under the condition of 50-60 DEG C; post-treatment: enzyme deactivation, centrifugation and drying are carried out after enzymolysis, and a polypeptide product is obtained. By adding the exogenous reducing sugar, nutrition is enhanced, and thallus proliferation is accelerated; bacillus licheniformis SWJS33 with high yield of aminopeptidase is inoculated, so that the generation of small-molecule active peptide is further promoted; a mixed bacteria composite system and a segmented fermentation technology are adopted, and bacteria cells are crushed in an ultrasonic-assisted manner, so that the enzymolysis efficiency is enhanced, and the yield and activity of the polypeptide are remarkably improved.

The present disclosure provides compounds of Formula (I), which have activity as inhibitors of aminopeptidase enzymes. The present disclosure provides methods and uses of the compounds in the treatment of diseases, particularly conditions and diseases associated with aminopeptidase.

The present invention relates to a pharmaceutical composition for treating peptic gastric ulcer and a preparation method thereof, belonging to the field of biotechnology. The pharmaceutical composition contains chicken gizzard-membrane peptide, pumpkin seed extract, complex bacteria, white hyacinth bean flower extract and bletilla striata extract; the chicken gizzard-membrane peptide contains the products obtained by successively subjecting chicken gizzard-membrane to fractional enzymolysis with pepsin, chymotrypsin and keratinase; the pumpkin seed extract contains the products obtained by subjecting pumpkin seeds to co-enzymolysis with cellulase and pectinase and then successively to fractional enzymolysis with pepsin, nattokinase and aminopeptidase; the complex bacteria contain the co-fermentation bacteria of Lactobacillus acidophilus, Bifidobacterium and Lactobacillus casei; the white hyacinth bean flower extract is an ethanol percolation extract; the bletilla striata extract contains the products obtained by subjecting bletilla striata tubers to co-enzymolysis with cellulase and pectinase and then successively to fractional enzymolysis with pepsin, bromelain and serrapeptase. The various components are used in combination, having a good therapeutic effect on gastric ulcer, quickly and efficiently repairing gastric mucosa, and being safe and free of side effects.

The present invention belongs to the field of genetic engineering and enzyme engineering, and relates to a chassis strain lacking the bglS gene and its application. The present invention provides a genetically engineered chassis strain of Bacillus subtilis, wherein the chassis strain is constructed by deleting the glucanase encoding gene on the Bacillus subtilis host genome. bglS The described chassis bacteria can efficiently express alkaline protease, aminopeptidase, mesophilic α-amylase, and thermostable α-amylase. This method is also suitable for increasing the expression of other exocrine proteins, laying the foundation for efficient expression of heterologous proteins and promoting the efficient expression and industrial production of alkaline protease, aminopeptidase, mesophilic α-amylase, and thermostable α-amylase.

The invention relates to the field of enzyme engineering, and discloses an aminopeptidase mutant as well as a coding gene, a recombinant vector, a recombinant strain and application thereof, and the aminopeptidase mutant is obtained by performing mutation of at least one of S88L, Y150C and Q268F on an enzyme with an amino acid sequence as shown in SEQ ID NO: 1. The aminopeptidase mutant disclosed by the invention can catalyze L-histidine to synthesize L-carnosine in a high-selectivity manner in the presence of beta-alanine methyl ester, and the aminopeptidase mutant has relatively high L-carnosine yield and relatively low impurity content, and has industrial application value.

The present invention relates to a composition for bone repair and growth and a preparation method thereof, belonging to the field of medical technology. The composition includes a peptide extracted from the gelatinous layer of sand jellyfish and a bamboo yellow-Grifola frondosa composite bacterial peptide; the peptide extracted from the gelatinous layer of sand jellyfish contains a product between 500Da and 2000Da obtained by sequentially hydrolyzing the gelatinous layer of sand jellyfish with lumbrokinase, serrapeptase, and transglutaminase; the bamboo yellow-Grifola frondosa composite bacterial peptide contains a product between 500Da and 2000Da obtained by co-enzymatic hydrolysis of bamboo yellow mushrooms and Grifola frondosa mushrooms with cellulase and chitinase, then co-enzymatic hydrolysis with nattokinase and serrapeptase, and finally co-enzymatic hydrolysis with aminopeptidase and transglutaminase. The present invention adopts a special method to prepare the peptide extracted from the gelatinous layer of sand jellyfish and the bamboo yellow-Grifola frondosa composite bacterial peptide, and the combined use achieves good biological activity, stability, and absorption utilization rate, overcomes the defects of existing bone repair and growth drugs, and effectively promotes bone repair and growth.

The invention belongs to the technical field of medicines, and discloses a near-infrared fluorescent probe Cy-NEO-Leu for leucine aminopeptidase responsiveness as well as a preparation method and application of the near-infrared fluorescent probe Cy-NEO-Leu. The parent nucleus of the probe is of a heptamethyl cyanine structure, and the probe has high molar absorption coefficient, high fluorescence quantum yield and excellent phototherapy characteristics. The introduction of a neomycin group can increase the water solubility of the probe, and a neomycin multi-ammoniation structure exists in a polycation form under physiological conditions and can target negatively charged cell walls of gram-negative bacteria, so that the probe Cy-NEO-Leu is enriched around the bacteria, can be specifically recognized by leucine aminopeptidase and can be hydrolyzed and activated; and photo-thermal and photodynamic sterilization effects are achieved under laser irradiation. Due to the good biocompatibility, the remarkable active oxygen generation capacity, the excellent photo-thermal conversion efficiency and the unique property of accurately targeting bacteria, the Cy-NEO-Leu is expected to play an important role in a photo-thermal / photodynamic combined treatment scheme, and is used for resisting diseases caused by bacteria and biological membranes and accelerating the healing process of wounds.

The invention provides a sugarcane fermentation product, a food quality guarantee product, a preparation method and application, and particularly belongs to the technical field of food preservation. The preparation method of the sugarcane leavening comprises the following steps: crushing sugarcane, and performing first sterilization to obtain sterile sugarcane pulp; inoculating the compound bacteria into the sterile sugarcane pulp for fermentation; the compound bacteria comprise lactic acid bacteria, bifidobacterium bifidum and propionibacterium; a degerming compound enzyme is supplemented in the fermentation process; the compound enzyme comprises xylanase, sucrase, phytase and aminopeptidase; and after fermentation, carrying out secondary sterilization, filtering, and discarding filter residues to obtain the sugarcane fermentation product. The sugarcane leavening disclosed by the invention is prepared from natural raw materials, has good anti-corrosion and anti-oxidation effects, and can prolong the shelf life of food.

The invention discloses sea cucumber peptide powder as well as a preparation method and application thereof, and belongs to the technical field of marine byproduct processing. Comprising the following steps: (1) mashing sea cucumber viscera, adding water, flavourzyme and aminopeptidase for enzymolysis, after enzymolysis is completed, performing enzyme deactivation, and performing centrifugation to collect supernatant; (2) adding a chitosan-acetic acid solution, stirring and mixing, centrifuging again, and collecting supernatant; and (3) carrying out rotary evaporation and drying to obtain the sea cucumber peptide powder. According to the preparation method disclosed by the invention, protein is dissolved out to the greatest extent by virtue of an enzymolysis process of cutting off different amino acid targets through double-enzyme compounding, and the proportion of components with molecular weights of 1000Da or below in the obtained fresh-flavor sea cucumber oligopeptide is 72%. Through a double-enzyme composite enzymolysis process, the obtained fresh sea cucumber oligopeptide is obvious in fresh taste, free of peculiar smell, good in solubility and rich in free amino acids and flavor nucleotides. The purpose of adsorbing and removing lipid is achieved by adding chitosan, so that the enzymatic hydrolysate is clarified.

The present invention relates to a hydrolyzed collagen formulation for use in decreasing blood glucose. The hydrolyzed collagen is obtained by enzymatic hydrolysis of a collagen-containing material with a combination of enzymes comprising two or more enzymes selected from the group consisting of a neutral protease, a carboxypeptidase, and an aminopeptidase. The hydrolyzed collagen formulation is particularly suitable as a food supplement, such as for use in ameliorating hyperglycemia and / or a risk factor hyperglycemia.

The invention discloses an LAT1-mediated STING agonist prodrug as well as a preparation method and medical application thereof, and belongs to the technical field of medicines. In order to solve the problem of specific delivery of the STING agonist, a series of LAT1-mediated STING agonist prodrug molecules are designed and synthesized, the molecules enter tissues through recognition and transportation of LAT1, then the STING agonist molecules are subjected to hydrolysis bond breaking through esterase or aminopeptidase, and the STING agonist molecules are released, so that the STING-activated non-specific immunocompetence is realized.

Disclosed are a specific marker combination of mesenchymal stem cell-derived small extracellular vesicles and the use thereof. The characteristic marker combination comprises aminopeptidase N (CD13), integrin β-1 (CD29), membrane glycoprotein THY-1 (CD90), and markers CD9, CD63 and CD81. By using the characteristic marker combination of mesenchymal stem cell-derived small extracellular vesicles for nano-flow cytometry analysis at the single-vesicle level, mesenchymal stem cell-derived small extracellular vesicles can be identified. On the basis of the provided characteristic marker combination, specific modification and engineering on the basis of small extracellular vesicle membrane proteins can further be realized.

The application belongs to the technical field of fluorescent probe, and particularly relates to an aminopeptidase fluorescent probe and a preparation method and application thereof. In order to develop an APN near-infrared fluorescent probe suitable for in vivo imaging, a center-position ester group substituted pentamethine cyanine dye platform (Cy5-COOM) is used, and based on an "ester group to carboxyl group" conversion strategy, an aminopeptidase (APN) fluorescent probe Cy5-APN is developed. The probe is firstly hydrolyzed by APN, then a 1,6-elimination reaction occurs, and finally a strong fluorescent center-position carboxyl group substituted pentamethine cyanine dye Cy5-COO is released. In addition, in view of the characteristics that cancer cell surfaces overexpress APN, the probe can distinguish cancer cells / tissues and normal cells / tissues with high contrast, and therefore has great application potential in fluorescence-guided tumor surgery.

The present application relates to a kind of by knocking out Bacillus subtilis SacB gene constructed chassis strain and its application, belong to genetic engineering, enzyme engineering and food engineering technical field.The present application is by SacB gene on the genome of Bacillus subtilis Knocking out, obtain a kind of can efficiently express aminopeptidase, alkaline protease Bacillus subtilis expression system, lay the foundation for the efficient expression of protein, promote the efficient expression and industrial production of aminopeptidase, alkaline protease.The chassis strain described above, in the case of carrying aminopeptidase, alkaline protease expression cassette, respectively, 48H shake flask fermentation, fermentation broth aminopeptidase enzyme activity is as high as 1666.7U / mL, with the enzyme activity of starting strain as contrast, enzyme activity is increased by about 30%;Fermentation broth alkaline protease enzyme activity is as high as 6348U / mL, with the enzyme activity of starting strain as contrast, enzyme activity is increased by about 20%.

The invention belongs to the technical field of pet food, and particularly relates to a protein cat food flavoring agent and a preparation method thereof.The preparation method of the protein cat food flavoring agent comprises the steps that meat extract, silkworm chrysalis homogenate, euphausia superba homogenate, pollen pini, ethyl maltol, a flavoring agent, trypsin, neutral protease and aminopeptidase are sequentially added for enzymolysis; an enzymolysis product is obtained; adding goat milk powder, carbohydrates, microencapsulated thiamine, pumpkin powder and amino acid into the reaction tank, uniformly mixing with the enzymolysis product, and carrying out Maillard reaction; after the Maillard reaction is finished, phosphoric acid and a thickening agent are added into the reaction tank, and a pasty flavoring agent is obtained; and carrying out spray drying on the pasty flavoring agent to obtain a powdery flavoring agent. The components jointly act on the cat food flavoring agent, so that the nutritional value of the flavoring agent is improved, the flavor level of the flavoring agent is richer and diversified, the flavoring agent can meet the favor of cats for flavor, and meanwhile, comprehensive nutritional support is provided.

The invention provides a fluorescent probe compound which is novel in structure and shown in a formula (I) and application of the fluorescent probe compound in detection of aminopeptidase N. The fluorescent probe compound can detect the aminopeptidase N in an aqueous solution system, has specificity, excellent selectivity, high sensitivity and the like on detection of the aminopeptidase N and can be used for quantitative detection of the aminopeptidase N. The preparation method of the fluorescent probe compound as shown in the formula (I) is simple in synthesis step, good in biocompatibility, short in reaction time, convenient to purify and simple in process.