45 results about "Peptide library" patented technology

Featured are devices, systems, and methods of use for detecting binding of polynucleotide-peptide conjugate-major histocompatibility complex (pMHC) monomers to a T cell receptors (TCR) on a T cell, and the use of a peptide library to detect binding of antigenic peptides in a pMHC monomer to a T cell receptor (TCR) on a T cell.

This invention discloses a universal detection method for tumor antigen-specific thymus-dependent lymphocytes in a broad population of East Asia, applicable to lung cancer and gastrointestinal cancers. The broad-spectrum T-cell epitope peptide library used in this detection method contains specific antigen T-cell epitope peptides presented by 13 HLA-A molecules, 15 HLA-B molecules, and 14 HLA-C molecules with an allele frequency greater than 1% in the East Asian population. The total gene frequencies of these dominant HLA-A, B, and C molecules account for approximately 95%, 71%, and 93% of the Chinese population, respectively, and are similar in total gene frequencies in Northeast and Southeast Asian populations. Therefore, this detection method is applicable to the vast majority of individuals in this region, providing a universal method for evaluating specific tumor antigen-specific T-cell immune function in patients with lung cancer or gastrointestinal tumors.

The invention relates to a preparation method and application of an oligopeptide / polypeptide substitution antibody, and belongs to the technical field of antibody preparation. In order to solve the problems that an existing antibody preparation method is high in complexity, poor in stability and limited in platform applicability, the invention provides a preparation method of an oligopeptide / polypeptide substitution antibody, firstly, a random DNA sequence is synthesized and cloned to a two-hybrid system prey vector to construct a peptide library, an antigen protein is cloned to a two-hybrid system bait vector, and then the oligopeptide / polypeptide substitution antibody is obtained. Screening an antigen interaction peptide sequence through bait and prey library two-hybrid interaction, and performing prokaryotic expression purification or direct artificial synthesis on the antigen interaction peptide sequence to obtain a short peptide / polypeptide interacting with an antigen protein as an antibody substitute. According to the invention, ethical dispute and batch difference of animal immunity in traditional antibody preparation are avoided, period is shortened, cost is reduced, non-specific binding is less, sensitivity is greatly improved, plant endogenous non-tag protein can be specifically recognized, and the method is widely applicable to scenes of antibody substitution.

The application discloses a method for determining key amino acid residues of bone collagen peptide promoting osteogenesis activity, belongs to the field of biological medicine and food science, and aims to solve the technical problem that traditional methods are low in efficiency, insufficient in accuracy, and cannot efficiently identify key amino acid residues of bone collagen peptide determining the activity of promoting osteogenesis. The application comprises the following steps: firstly, obtaining target bone collagen peptide and constructing a single-point alanine mutant peptide library thereof; then, sequentially performing conformation and physicochemical property characteristic analysis, binding free energy simulation calculation with specific receptor protein, and cell experiment determination of the activity of promoting osteogenesis on the target peptide and the mutant peptide; finally, screening the key amino acid residues based on multi-level joint determination of characteristic deviation, binding free energy change and activity decline ratio. The application is mainly used for quickly and accurately positioning the core functional site of bone collagen peptide promoting osteogenesis activity, and provides key theory and technical basis for efficient screening, rational design and function strengthening of osteogenic activity peptide.

The invention aims to provide a peptide for accelerating fat metabolism and application thereof, the peptide is prepared into a product convenient to use, and the amino acid sequence of the peptide is MVHSYSETSD. The peptide is obtained through peptide library screening, bioinformatics analysis screening and fat cell decomposition experiment verification, and it is verified that the active peptide obtained through screening has the effects of accelerating fat metabolism, inhibiting fat accumulation, reducing blood fat and body fat content and reducing body weight; the insulin sensitivity and the glucose tolerance are improved, and the prevention and treatment effects on obesity and complications thereof are realized.

The application aims to provide a peptide for accelerating fat metabolism and application thereof, and to prepare the peptide into a product convenient to use, and the amino acid sequence of the peptide is MVHSYSETSD. The peptide is obtained through screening of a peptide library, screening through bioinformatics analysis, and verification through fat cell decomposition experiment, and the application verifies that the active peptide screened has the effect of accelerating fat metabolism, inhibiting fat accumulation, reducing blood fat and body fat content, reducing body weight, improving insulin sensitivity and glucose tolerance, and realizing the prevention and treatment effect on obesity and its complications.

This invention discloses umami peptides derived from Litopenaeus vannamei and their applications, belonging to the field of bioactive peptide technology. Seven umami peptides are described, with amino acid sequences as follows: ASRM, RCNG, DNCY, GAEF, DEGF, EDMQF, and PNRMPY, as shown in SEQ ID NO. 1–7. The invention also discusses the application of these umami peptides as or in the preparation of umami enhancers. This invention utilizes virtual screening and molecular simulation techniques to discover new umami peptides from the protein sequences of Litopenaeus vannamei, enriching the marine umami peptide library. Furthermore, it investigates the key amino acids and mechanisms of action of umami peptide receptor binding, providing a reference for studying the umami presentation mechanisms of peptides with different structures.

This invention proposes a method for screening bisphenol A-specific peptides using molecular simulation, belonging to the field of food safety technology. The method includes the following steps: 1) Through protein stacking and molecular docking, the molecular structure and interactions of bisphenol A-protein cocrystal compounds in a protein structure database are comprehensively analyzed to obtain the receptor protein and the original parent chain; 2) Based on the original parent chain obtained in step 1), the parent peptide is obtained by truncation of the parent peptide segment by analyzing the main active amino acids in the molecular docking results; 3) By performing virtual amino acid mutations on the parent peptide obtained in step 2), a peptide library specifically binding to bisphenol A is constructed, and molecular dynamics is used for preliminary screening of the peptides; 4) The peptide chains screened in step 3) are used as specific recognition elements, and peptides labeled with fluorescein isothiocyanate are used to form specific recognition probes. The specific recognition probes are mixed with bisphenol A, and the peptide sequences with the strongest specific binding ability to bisphenol A are screened based on the different fluorescence differences. This invention is mainly applied to the screening of specific recognition elements for toxic and harmful small molecules, active ingredients, and functional factors. This method avoids the complex preparation steps of antibodies and the cumbersome screening process of aptamers, achieving high-throughput design of specific recognition elements.

The present disclosure provides a peptide library comprising stable isotope-labeled (SIL) peptides, wherein the peptides comprise or consist of the sequences according to Table A, Table B, or Table C.

Disclosed is a fluorescently labeled peptide library useful for diagnosing multiple sclerosis. The fluorescently labeled peptide library comprising fluorescently labeled peptides represented by the following formula:wherein X1, X2, X3 and X4 are independently arbitrary amino acid residues, and the peptides are immobilized on a chip.

The present disclosure provides a method for biocatalytic production of a polycyclic peptide comprising providing a peptide sequence containing a recognition motif for a radical S-adenosylmethionine metallocnzyme (SAM enzyme), exposing the peptide sequence to an enzymatic reaction including catalysis under standard enzymatic reaction conditions with the radical SAM enzyme, and generating a further cyclized peptide by modifying a product of the enzymatic reaction chemically and / or via enzymes. The radical SAM enzyme catalysis generates macrocyclic modifications using unactivated carbon centers. The product of the enzymatic reaction may be modified using haloalkane- or haloacetyl-containing compounds, macrocyclases, or additional radical SAM enzymes. The peptide sequence may be altered at permissive sites to generate libraries of polycyclic peptide structures. The enzymatic reaction may occur at ambient temperature and pH under buffered aqueous conditions.

The invention discloses a construction method of a jellyfish toxin metalloproteinase substrate peptide library, and relates to the technical field of biology. The construction method comprises the following steps: inducing mice with different dermatitis degrees by using a metalloproteinase inhibitor and jellyfish toxin; skin tissues with different dermatitis degrees are collected for proteome identification, and substrate membrane proteins of jellyfish toxin metalloproteinase are analyzed and screened through bioinformatics; screening by utilizing a protein database to obtain a potential substrate sequence in the substrate membrane protein; and screening sequences from the potential substrate sequences according to application conditions to construct a peptide library, and synthesizing the jellyfish toxin metalloproteinase substrate peptide library. The sequence contained in the jellyfish toxin metalloproteinase substrate peptide library constructed by the method is clear, the effect that the prepared polypeptide is hydrolyzed by toxin is remarkable, and the application prospect of the peptide library in jellyfish stings research is further guaranteed.

The invention relates to the technical field of biology, in particular to affinity polypeptide of human serum albumin and a design method of the affinity polypeptide. The molecular mechanism and microscopic details of interaction of HSA-Mgbc7HopQNbAlb1 compounds are analyzed through an MD simulation technology and an MM-PBSA free energy decomposition method, key binding sites between the compounds and spatial distribution of the key binding sites are determined, and an affinity model is established, so that a candidate affinity polypeptide library is constructed, and meanwhile, the peptide library is expanded through intelligent design. Then, screening and verifying the affinity polypeptide library through methods of molecular docking, conformation analysis, hydrophobicity analysis, MD simulation and the like, so as to obtain the high-affinity polypeptide aiming at the HSA target spot. The binding performance of the affinity polypeptide and the HSA is verified through a double-antibody one-step sandwich ELISA experiment, adsorption isotherm determination and an affinity chromatography experiment. The polypeptides such as FKITSGSLSR, DGALTPPSEY and the like obtained by screening have high affinity with the HSA (Human Serum Albumin).

The invention relates to a human mesenchymal stem cell-derived mitochondrial active peptide library as well as a construction method and application thereof. Specifically, the invention provides a mitochondrial active peptide library, and active peptides can be utilized in vivo through gastrointestinal digestion and absorption, liver metabolism and blood circulation, have obvious curative effects on cartilage regeneration and the like, and provide candidate drugs for regenerative medicine.

The invention relates to the technical field of biology, in particular to a p53 protein targeting inhibitor and a design method thereof. The molecular mechanism and microscopic details of interaction of azurin-p53 protein complexes are analyzed through an MD simulation technology and an MM-PBSA free energy decomposition method, key binding sites between the complexes and spatial distribution of the key binding sites are determined, and an affinity model is established, so that a candidate affinity ligand peptide library is constructed. Then, screening and verifying the affinity ligand library through methods of molecular docking, conformation analysis, binding site comparison, hydrophobicity analysis, MD simulation and the like to obtain a high-affinity ligand aiming at a p53 protein target spot, and verifying the binding performance of the affinity peptide ligand and the p53 protein through a double-antibody sandwich ELISA (Enzyme-Linked Immunosorbent Assay) experiment. And screening to obtain the p53 protein inhibitory peptide with high affinity with the p53 protein.

This invention discloses a method for de novo design of antifungal peptides, the obtained peptides, and their applications. The method includes: S1 peptide library retrieval and amino acid preference analysis; S2 peptide design based on multiple parameters; S3 AI high-throughput screening of the peptide library to obtain candidate antifungal peptides. The amino acid sequences of the mentioned antifungal peptides are also disclosed in this invention as shown in SEQ ID Nos: 1 to 3. The antifungal peptides developed by this invention can specifically target and kill fungi such as Malassezia furfur without inhibiting the growth of other beneficial bacteria such as Propionibacterium acnes, thereby effectively regulating the skin surface microecological balance and maintaining skin health; solving the problem that current antimicrobial peptides, due to their broad-spectrum antibacterial properties, can disrupt the skin microecological balance and cause more serious skin diseases.

The application relates to a method for generating a target AAV9 antibody epitope affinity peptide ligand by using a protein language model and a screening method and application thereof, and relates to an affinity peptide candidate sequence construction and screening method, an affinity peptide ligand, an affinity medium and application thereof for targeting adeno-associated virus type 9 (AAV9). The AAV9 capsid region recognized by Fab2-4 is taken as a target, structure analysis, natural amino acid positioning, key residue extraction and affinity peptide template construction are carried out, a candidate peptide library is generated by using a protein language model, and a candidate affinity peptide ligand is screened by combining molecular docking, binding free energy evaluation, refined docking and molecular dynamics simulation. The affinity peptide ligand is any one of SEQ ID NO. 1, SEQ ID NO. 2, SEQ ID NO. 3 or SEQ ID NO. 4, can be immobilized on a solid phase matrix to form an affinity medium, is used for AAV9 recognition, capture and purification, and provides a technical scheme for AAV9 purification process development.

The application discloses a pig antigen-presenting cell targeting peptide and application thereof, and the amino acid sequence of the pig antigen-presenting cell targeting peptide is shown as SEQ ID NO. 1 or SEQ ID NO. 6. The FcMR specific 12-peptide sequence of the pig is screened by using a phage random display peptide library, the obtained FcMR specific 12-peptide sequence is fused with a model antigen for expression, and the FcMR specific 12-peptide sequence with the APC targeting property is further screened. In subsequent animal experiments, it is determined that the specific targeting peptide has an obvious enhancement effect on an immune response, and has important significance for the research and development of a future pig APC targeting drug.

The invention discloses a porcine antigen presenting cell targeting peptide and application thereof. The amino acid sequence of the porcine antigen presenting cell targeting peptide is shown as SEQ ID NO. 1 or SEQ ID NO. 6. A pig FcMR specific targeting 12 peptide sequence is screened out by utilizing a phage random display peptide library, FcMR specific targeting 12 peptide with APCs targeting is further screened out after the obtained FcMR specific targeting 12 peptide sequence and a mode antigen are subjected to fusion expression, and it is determined that the specific targeting peptide has an obvious enhancement effect on immune response in subsequent animal tests. And the method has important significance on research and development of pig APCs targeted drugs in the future.

The invention provides a litopenaeus vannamei head umami peptide and a preparation method thereof, and the umami peptide is characterized in that the amino acid sequence of the umami peptide is selected from any one of the sequences as shown in SEQ ID NO: 1-5; the delicate flavor threshold value of the delicate flavor peptide is 0.2 to 0.5 mmol / L. According to the method, high-value utilization of the penaeus vannamei head byproducts is achieved, and the problems of wasting of aquatic product processing resources and environmental protection pain are effectively solved; five brand-new umami peptide sequences are obtained for the first time, the umami threshold value is far lower than that of monosodium glutamate, the synergistic fresh-increasing effect is outstanding, and the blank of an aquatic product source umami peptide library is filled.

The invention discloses umami peptide RCNG from litopenaeus vannamei. The amino acid sequence of the umami peptide RCNG is as shown in SEQ ID NO. 2. The umami peptide RCNG from the litopenaeus vannamei is applied to serving as a flavor enhancer or preparing the flavor enhancer. According to the present invention, the new umami peptide is explored from the litopenaeus vannamei meat protein sequence through the virtual screening, the molecular simulation and other technologies, such that the marine umami peptide library is enriched, the key amino acid combined with the umami peptide receptor and the action mechanism are researched, and the reference is provided for the research of the umami presentation mechanism of the peptides with different structures.

The present technology provides an approach to designing libraries of peptide sequences for discovery and testing of significantly more motifs than would be otherwise available in a given fixed library format. The technology includes a plurality of x-mers embedded in N-mer peptides sequences, where N and x are integers and where N is greater than x. This approach provides for the representation of multiple unique x-mer peptides in a single N-mer peptide feature.

The invention relates to the technical field of biology, and discloses an antioxidant peptide derived from fermented meat and application of the antioxidant peptide, the antioxidant peptide comprises minced pork, auxiliary materials and a composite leavening agent composition composed of lactobacillus sake and staphylococcus xylosus, and fermentation and maturation are carried out by controlling the inoculum size and adopting a two-stage temperature control process. The core innovation of the method is as follows: firstly, performing comprehensive peptide sequence identification on small molecular weight components extracted from a fermentation product by adopting liquid chromatography-tandem mass spectrometry, and then accurately predicting and locking a target antioxidant peptide from a peptide library by utilizing virtual screening technologies such as molecular docking and the like. The antioxidant peptide prepared by the invention can be used for effectively relieving cell oxidative damage induced by ethanol by activating a Kelch sample ECH associated protein 1-Nrf2 (Keap1-Nrf2) signal channel. According to the method, directional fermentation and computational biology are combined, a new normal form is provided for efficiently discovering novel active peptides from natural products, and the research and development efficiency is effectively improved.

The application discloses a kind of small molecule polypeptide for treating psoriasis and its pharmaceutical composition and application.The application obtains a kind of small molecule polypeptide S1 from peptide library, which can be stably combined with cell receptor in psoriasis skin, and the small molecule polypeptide is composed of CNAGQRSEC ring peptide, and the small molecule polypeptide can inhibit the proliferation of human keratinocytes.In the application, further add medical acceptable adjuvant (such as transdermal absorption agent, fat-soluble matrix, emulsifying agent, humectant, pH regulator and antioxidant, etc.) on the basis of small molecule polypeptide S1, it is made into pharmaceutical cream, can significantly improve the stability and transdermal capacity of drug, realize the effective treatment of psoriasis.

A method for co-compartmentalising a cyclic polypeptide with a polynucleotide encoding the cyclic polypeptide, comprising the steps of a) forming a compartment containing a polynucleotide encoding the cyclic polypeptide, b) expressing a polypeptide from the polynucleotide, and c) cyclising the polypeptide. Co-compartmentalised cyclic polypeptides and encoding polynucleotides. Libraries of co-compartmentalised cyclic polypeptide and encoding polynucleotide. Methods for screening libraries of co-compartmentalised cyclic polypeptide and encoding polynucleotide. Incorporation of non-canonical nucleic acids into such libraries.

The invention discloses a screening method of a jellyfish toxin metalloproteinase substrate sequence, and relates to the technical field of biology. The screening method comprises the following steps: regulating and controlling the metalloproteinase activity of the jellyfish toxin by using a compound protease inhibitor, inhibiting the activity of nonmetal protease in the toxin, retaining the metalloproteinase activity and causing significant difference of the metalloproteinase activity; the hydrolysis effect of the jellyfish toxin on a substrate peptide library is detected, and it is ensured that toxins with different enzyme activities have significant differences on the hydrolysis capacity of the substrate peptide library; and identifying the hydrolysate of the substrate peptide library, and screening the jellyfish toxin metalloproteinase substrate sequence in combination with the change trend of toxin enzyme activity and the change trend of hydrolysate abundance. By adopting the screening method, a toxin metalloproteinase substrate sequence and a cleavage site can be successfully analyzed by utilizing the jellyfish crude toxin, so that a technical support is provided for research and development of polypeptide drugs stung by jellyfish.

A method for constructing a DNA-encoded library, specifically, (s1) providing an HP module, the HP module comprising a nucleic acid; (s2) covalently attaching chemical structural units to the HP module to form chemical moieties attached to the HP module, while covalently attaching oligonucleotides that encode the chemical structural units to the HP module to form encoded nucleic acid moieties of the HP module, thereby forming a nucleic acid-compound conjugate; (s3) subjecting the nucleic acid-compound conjugate to a linking reaction with a compound shown in formula (II) to obtain a first mixture; S-R5 (II), wherein the S is a solid-phase carrier, and R5 is a second group participating in the linking reaction; (s4) subjecting the first mixture to filtration, washing, and purification, and then to cleavage to obtain a new compound; and (s5) repeating steps (s2)-(s4) x times, wherein x is an integer greater than 0, thereby forming a DNA-encoded library. The obtained DNA-encoded library has a larger load capacity, high purity, a larger peptide library, and wider applicable reactions.

The invention provides a specific monoclonal antibody for resisting pseudorabies virus IE180 protein as well as a preparation method and application of the specific monoclonal antibody, and belongs to the technical field of biological medicines. The invention provides a hybridoma cell strain pIE180 mAb for producing a specific monoclonal antibody against the pseudorabies virus IE180 protein, and successfully prepares the monoclonal antibody against the PRV IE180 protein. An overlapping peptide library technology shows that the monoclonal antibody can recognize a new B cell epitope, and the epitope is highly conservative in various classic and mutant isolates, can be used for specific detection of PRV infection and development of diagnostic reagents, provides an important molecular basis for design of subunit vaccines, and has broad application prospects. Important clinical application and market prospects are realized.

Methods and systems are provided herein for selecting an affinity reagent which binds a desired peptide epitope in a plurality of sequence contexts. The method relies on obtaining a peptide library, each peptide having the sequence αXβ, wherein X is the desired peptide epitope, wherein each of α and β comprise an amino acid, using the peptide library to select an affinity reagent.