30 results about "Protein surface" patented technology

The invention relates to a ZIKV nano vaccine as well as a construction method and application thereof, the ZIKV nano vaccine is prepared by mixing an SC-Mi3 fusion protein and an EDIII-ST fusion protein, and carrying out self-assembly connection through a SpyTag connecting peptide in the SC-Mi3 fusion protein and a SpyCatcher connecting peptide in the EDIII-ST fusion protein, so as to obtain a nano particle vaccine with Mi3 as a core and ZIKV EDIII protein displayed on the surface. The SC-Mi3 fusion protein is formed by fusing a SpyCatcher connecting peptide into Mi3 nano particles, and the EDIII-ST fusion protein is formed by fusing a SpyTag connecting peptide into a ZIKV EDIII protein. The ZIKV nano vaccine can induce a strong specific neutralizing antibody aiming at ZIKV, can resist lethal attack of ZIKV and avoids ADE reaction.

The application discloses a duck Riemerella anatipestifer (RA) surface adhesion factor 3-glyceraldehyde-3-phosphate dehydrogenase protein (GAPDH) conservative B cell epitope peptide, a nucleic acid molecule, a recombinant carrier and application thereof. The application inserts the conservative B cell epitope TG12 into chicken white dysentery Salmonella Peg fimbria, introduces the inert carrier bacteria, and obtains the recombinant bacteria which can functionally express and present the RaGAPDH protein surface conservative B cell epitope peptide. The expression and presentation of the conservative B cell epitope can specifically recognize and combine duck and goose RA infection serum, and the naked-eye visible agglutination reaction particles are observed, and there is no cross agglutination reaction with other pathogen infection positive serum. The agglutination detection method has the advantages of specificity and convenience, and is expected to provide a new idea and method for detection and prevention and control of RA infection.

The application discloses a method for detecting small molecules based on an aggregation-induced emission liquid crystal-polymer composite film, and applies the method to the detection of parathyroid hormone. The method introduces TPE-PPE molecules on the basis of traditional liquid crystal detection, prepares luminescent liquid crystals for the detection of substances, and compares the detection results of the fluorescence optical double channel. The optical image can only detect parathyroid hormone above 10 ug / mL, while the sensitivity of the fluorescence to the orientation of the liquid crystal molecules realizes the change of the aggregation state of the AIE, so that the fluorescence detection of the AIE liquid crystal (AIE-LCs) can realize the detection of 1 ng / mL. In addition, 5wt% of the prepolymer is introduced, and ultraviolet irradiation is performed for 8 s. Since the amorphous structure is formed on the surface of the protein, the detection signal is amplified, and the optical and fluorescence detection limits are simultaneously reduced to 0.01 ug / mL and 50 pg / mL respectively.

The invention belongs to the technical field of biological enzyme engineering, and particularly relates to a glucosamine-6-phosphate synthetase mutant and application thereof. A plurality of glucosamine-6-phosphate synthase mutants capable of remarkably improving the yield of N-acetylglucosamine are screened by performing single-point mutation or combined mutation on amino acid residues near a substrate binding pocket of the glucosamine-6-phosphate synthase or on the surface of protein of the glucosamine-6-phosphate synthase. According to the technical scheme, a foundation is laid for producing glucosamine by further transforming escherichia coli through metabolic engineering.

The invention relates to the technical field of food freezing, in particular to an anti-freezing agent for aquatic products as well as a preparation method and application of the anti-freezing agent. According to the invention, a binary compound system is formed by carboxymethyl chitosan oligosaccharide and sucrose ester, and based on a polar hydrophilic-hydrophobic synergistic protection strategy of saccharides, while the protection effect of a hydrophilic component on a protein surface hydration layer is fully exerted, a hydrophobic component is introduced to be directionally combined with a hydrophobic plaque of the protein; and full-range synergistic protection of hydrophilic coverage and hydrophobic shielding is realized, so that the concentration bottleneck of the traditional antifreeze agent is broken through under the condition of extremely low addition amount.

The invention provides a docking method, device and equipment for a protein surface structure and a drug target, and the method comprises the steps: obtaining the three-dimensional structure data of a protein, generating a surface mesh model based on the three-dimensional structure data, and extracting the multi-modal surface features of the protein; based on the surface mesh model and the surface features of the protein, constructing a multi-scale 3D graph convolutional network, and generating feature codes of the protein; performing nonlinear dimensionality reduction on the feature code of the protein based on an adversarial auto-encoder to generate a low-dimensional feature of the protein; and performing iterative reinforcement learning docking based on the low-dimensional features and ligand positions of the proteins to obtain an optimal docking result. Through the method and the device, the surface features of the protein are extracted more comprehensively and accurately, the calculation amount is greatly reduced, and the problem of poor docking accuracy in the prior art is solved.

The invention discloses an enzyme function prediction method based on three-dimensional point cloud characterization and multi-modal fusion. The method comprises the following steps: extracting point cloud features on the surface of protein by using dMaSIF to characterize geometric and chemical characteristics; the point cloud features are coded through the pre-trained Point Net + +; a decoupling cross attention mechanism is adopted to fuse PointNet + + point cloud coding, Sapot network structure coding and ESM-2 sequence coding, and the network is optimized through comparison learning based on sorting loss. The invention also provides an enzyme function prediction system based on three-dimensional point cloud representation and multi-modal fusion, and the system comprises a point cloud feature extraction module, a point cloud coding module, a multi-modal fusion module and an optimization module, and is used for realizing the method. By integrating the protein three-dimensional structure, sequence and multi-source information of surface physicochemical characteristics, the functional prediction accuracy and robustness are remarkably improved, and the method has excellent performance in enzyme classification (EC number prediction) tasks.

This invention discloses nanoparticles based on transcytosis-activating ligands, their preparation method, and applications, particularly in the treatment of fundus diseases. The nanoparticles comprise an enzyme protein core and a polymer shell grown in situ on the protein surface. The polymer shell contains positively charged monomers, transcytosis-activating ligands, and neutral monomers. The nanoparticles can enhance the hydrolytic resistance of enzyme proteins (e.g., antioxidant enzymes), protecting them from degradation during transport and improving delivery stability. Simultaneously, the nanoparticles can also promote the efficient delivery of proteases (especially to the posterior segment of the eye), exhibiting good safety and showing excellent application prospects in the medical field.

The invention belongs to the technical field of biological medicine and nano delivery, and particularly relates to a supramolecular assembly as well as a preparation method and application thereof. The supramolecular assembly constructed by the invention is based on mediation of a polyphenol molecular adhesive, the polyphenol molecular adhesive can generate relatively strong interaction with a target protein, so that the surface of the target protein is modified with a catechol group, and the catechol group on the surface of the target protein can be combined with a functional polypeptide modified with a phenylboronic acid group; dynamic chemical bonds are formed through catechol and phenylboronic acid, a compound beneficial to endocytosis of cells is formed, and therefore the binding problem of cationic polypeptide and target protein is solved. According to the invention, the functional polypeptide modified with phenylboronic acid is constructed by utilizing the principle, and a nano-scale supramolecular assembly is formed by virtue of multiple interaction synergistic driving of the polyphenol molecular adhesive and the target protein, so that an efficient, universal and safe new scheme is provided for intracellular delivery of protein drugs.

The invention belongs to the fields of biotechnology, protein engineering and plant protection science, and particularly relates to an antagonistic protein mutant for cultivating a sweet potato composite virus disease (SPVD) resistant plant and application of the antagonistic protein mutant. The key pathogenic factor of the SPVD is the RNase3 protein coded by the sweet potato chlorotic stunt virus (SPCSV), and the RNase3 protein is used as an RNA silence suppressor (RSS) to destroy host immunity. The invention provides an SPCSV-RNase3 antagonistic protein mutant, which is derived from a natural antagonistic protein, namely a sweet potato trypsin inhibitor (IbSPLTI-a). According to the present invention, a compound structure model (such as construction through AlphaFold2) of wild type IbSPLTI-a and RNase3 is analyzed, and the IbSPLTI-a is modified by using a protein directed evolution strategy, particularly by using a hotspot amino acid scanning and protein surface design strategy, such that the high-activity inhibition mutant (such as IbSPLTI-a-m0805) is successfully created and screened; in-vivo and in-vitro function verification shows that the binding affinity of the mutant (such as IbSPLTI-a-m0805) and SPCSV-RNase 3 is remarkably enhanced, and the mutant shows a virus accumulation inhibition effect superior to that of a wild type IbSPLTI-a. The invention also provides a nucleic acid sequence for coding the mutant, a plant expression vector containing the sequence, and a method for culturing an anti-SPVD transgenic plant (especially sweet potato) by using the mutant. The invention provides a core gene resource and a technical path for genetic improvement of SPVD and development of a novel antiviral protein preparation.

The invention relates to the field of food processing, and discloses a preparation method and application of high-protein cow milk, and the preparation method comprises the following steps: mixing pea protein isolate and feruloylated beet pectin in water; laccase is added into the mixed solution for an enzymatic grafting reaction in a controlled oxidation-reduction microenvironment, dispersion liquid containing the functional protein-pectin grafted copolymer is obtained, and construction of the microenvironment comprises the steps that oxygen reduction treatment is conducted before the reaction, and a preset low-concentration dissolved oxygen window is maintained in the reaction; and then mixing the dispersion liquid with a cow milk base material, and performing homogenization and ultrahigh-temperature sterilization treatment to obtain the high-protein cow milk. The hydrophilic polysaccharide chain is covalently grafted on the surface of the protein to form steric hindrance, and the reaction path is accurately controlled to inhibit side reaction, so that the prepared high-protein cow milk can still keep high physical stability, does not stratify or precipitate and is uniform in system even after being subjected to ultrahigh-temperature sterilization and long-term storage.

The present invention relates to the field of protein labeling or tracing, and particularly to a composition and method for labeling or tracing a target protein. The method first analyzes the structure of the target protein and identifies a loop sequence on the protein surface that faces outward. Then, through molecular cloning methods, a small tag (such as an HA tag) with flexible amino acid linker peptides at both ends is inserted into the middle of the loop sequence. Finally, a nanobody fused to the small tag and fused to a fluorescent protein is expressed. This method utilizes the nanobody's ability to specifically recognize the target protein surface tag to achieve intracellular tracing of the target protein.

The application provides a protein carrier-based active ingredient transdermal delivery system, which is a small-molecule active ingredient-protein-polymer composite structure, and comprises a small-molecule active ingredient, a protein loaded with the small-molecule active ingredient and a polymer coated on the surface of the protein. The application modifies a polymerizable double bond compound on the protein, loads the small-molecule active ingredient, and then initiates a polymerization reaction in situ on the surface of the protein after loading the small-molecule active ingredient, so as to coat a polymer protective layer on the surface of the protein. The polymer protective layer is biocompatible, and the surface properties of the polymer layer can be regulated according to the transdermal depth requirement. The protein and the active small molecule are targeted to be delivered transdermally while breaking through the skin barrier, and the defects of poor delivery efficiency of the previous protein delivery system are significantly improved. The preparation method of the transdermal delivery system is simple, the yield is high, and the system can be produced on a large scale.

A method for extracting protein surface features, a method for generating an extraction model, and related equipment are disclosed. The method includes: acquiring a protein surface fingerprint descriptor training dataset, which comprises surface fingerprint descriptor data of multiple protein molecular structure data at corresponding scaling scales. The scaling scale is related to the size, shape, and surface complexity of the protein molecular structure data, as well as computational requirements including computational efficiency and accuracy. A neural network is trained using the protein surface fingerprint descriptor training dataset to obtain a protein surface feature extraction model. The technical solution of this invention enables protein surface feature extraction at multiple scales, meets diverse user requirements for computational efficiency and accuracy, and helps improve the accuracy of protein surface feature extraction.

The purpose of the present application is to provide a method and device for predicting the change of protein complex affinity caused by mutation, which comprises: using a first sub-network in a twin network, determining wild-type multi-modal encoding information including wild-type sequence encoding information and wild-type geometric feature encoding information discretely encoded based on wild-type protein complex information and mutation information; then determining the affinity information of the wild type through a decoder; determining the affinity information of the mutant through a corresponding second sub-network; and then determining the affinity change information. Through the use of discrete encoding and multi-modal information, the model can cope with the situation that the local structure optimization is not good, so that the model can obtain more accurate affinity change prediction results using complex information with low precision. Moreover, the introduction of protein surface information helps the model to better learn the influence of the cavity formed by the protein interaction interface on the affinity change, further improving the accuracy of affinity change prediction.

The present application relates to the technical field of protein and peptide, and particularly relates to a kind of high anti-oxygen activity bird's nest peptide and preparation method of its tablet.The present application includes the following steps: preparation of modified bird's nest product;Multiple enzymolysis of modified bird's nest product;Strengthening of bird's nest peptide anti-oxygen stability.The present application can not only enhance the antioxidant capacity of bird's nest by the free radical reaction of resveratrol grafted on the surface of bird's nest protein, but also improve the water solubility of bird's nest, which is helpful for the subsequent enzyme and bird's nest to better contact, improve the enzymolysis efficiency, avoid the reduction of bird's nest peptide anti-oxygen activity caused by external oxidation factors and too long enzymolysis time, then the bird's nest is glycosylated by chitosan, which can not only improve the dispersion emulsification stability of modified bird's nest product, enhance the contact area of subsequent enzyme and modified bird's nest product, further enhance the antioxidant capacity and the efficiency of subsequent enzymolysis.

The invention discloses an inhalation type drug delivery system with a phospholipid-protein surface active structure and application of the inhalation type drug delivery system. The inhalation type drug delivery system comprises liposome vesicles modified by PEG (polyethylene glycol)-angiotensin converting enzyme II substrate polypeptide, and alveolar surface active substances are loaded in the liposome vesicles. According to the inhalation type drug delivery system, the drug can be delivered into the lung in an aerosol inhalation mode and can be evenly distributed in pulmonary alveoli, pulmonary alveoli development can be effectively promoted, the ventilation function can be improved, and the inhalation type drug delivery system has a good curative effect in premature infant pulmonary dysplasia treatment. According to the inhalation type pulmonary alveolar surface active substance delivery system, an existing administration mode that liquid drops are dropped through a trachea cannula is changed, and the problems that segmental pulmonary atelectasis, asphyxia and the like are possibly caused are solved. The inhalation type drug delivery system can be stably and efficiently degraded when reaching the pulmonary alveoli, and is safe and low in toxicity.

The present invention provides a computer-implemented method for determining at least one therapeutic target region on a candidate protein of a target pathogenic organism, the method comprising: a) identifying pairs of invariant and / or lethal synthetic residues, called target residues, in a set of pre-aligned nucleotide and polypeptide sequences characteristic of a candidate protein (E1); b) identifying at least one candidate region (E2) consisting of at least one pair of target residues identified in step a), wherein at least one pair is located at a determined distance in space and comprises target residues exposed on the surface of the candidate protein, preferably in a pocket; c) determining (E3) from the 2D and / or 3D structure of the candidate protein favorable chemical interactions between each residue and / or each pair of residues in the candidate protein, wherein the favorable chemical interactions are hydrophobic bonds and / or hydrogen bonds and / or salt bridges and / or negative repulsive bonds and / or positive repulsive bonds; d) selecting residues that are linked by favorable chemical interactions, the residues being at a distance of at most 10 Angstroms (E4); e) selecting from among the candidate regions identified in step b) at least one therapeutic target region comprising the residue selected in step d) (E5).

This application relates to the field of bioassay technology, and more particularly to a detection reagent, kit, and application for bioanalysis. The detection reagent includes a conditioning medium, which comprises a buffer system. Through innovative component combinations and formulation optimization, it aims to reduce non-specific adsorption, improve the signal-to-noise ratio and detection sensitivity. In particular, the introduction of specific amino acid-based buffers can interact with hydrophobic regions on protein surfaces, reducing non-specific adsorption and significantly improving the performance of bioanalytical detection.

This invention discloses an EC hydrolase mutant with enhanced enzyme activity and tolerance, and its applications, belonging to the field of enzyme engineering technology. First, this invention identifies the disulfide bond site Q149C-F157C in the flexible region, constructing disulfide bonds between the α-helical structures on the protein surface, successfully significantly improving the stability of multiple aspects of the ES8 mutant V129S / I229M. Experimental data show that the mutant exhibits improved stability under different environments; the stability at 80℃ half-life, pH 4.0, and 20% ethanol is 8.14 times, 1.49 times, and 2.72 times that of Est8-CE, respectively. Molecular dynamics simulation analysis of protein structural changes shows that the introduction of disulfide bonds significantly reduces the RMSD and RMSF of Est8-CE, demonstrating enhanced structural stability and promising suitability for use in extreme environments, thus possessing greater industrial application value.

The invention discloses an EC hydrolase mutant with improved enzyme activity and tolerance and application of the EC hydrolase mutant, and belongs to the technical field of enzyme engineering. According to the present invention, the disulfide key site Q149C-F157C constructed in the flexible region is firstly determined, and the disulfide bond between the alpha-helical structures on the protein surface is constructed, such that the multi-term stability of the ES8 mutant V129S / I229M is successfully and significantly improved; experimental data show that the stability of the mutant in different environments is improved, the half-life period at 80 DEG C is 8.14 times that of Est8-CE, the stability of the mutant in a pH 4.0 environment is 1.49 times that of Est8-CE, and the stability of the mutant in a 20% ethanol environment is 2.72 times that of Est8-CE. Molecular dynamics is used for simulating and analyzing protein structure change, a trajectory analysis result shows that RMSD and RMSF of Est8-CE are remarkably reduced due to introduction of disulfide bonds, it is proved that the structural stability of the mutant is enhanced, and the mutant is expected to be used in an extreme environment and has higher industrial application value.

The present application belongs to the technical field of computational biology, and particularly relates to a protein surface multi-level modular representation method and an interaction interface prediction method. First, a protein manifold triangle mesh containing multi-modal physical and chemical characteristics is constructed. Then, based on the geodesic distance and local density field, the continuous surface is discretized into geometrically compact virtual residues using a restricted region growing algorithm. Next, an improved soft subspace clustering is used to mine atom patterns with specific functions, and a graph-guided manifold autoencoder is introduced to map them into high-dimensional embedding vectors. On this basis, a compatibility network is constructed by fusing statistical, semantic and physicochemical characteristics, frequent sub-patterns are mined, and the surface is resolved into a structured sub-pattern sequence. Finally, a graph neural network model is constructed for PPI prediction, and the prediction area is resolved into core modules and variable modules. The present application uses a unique four-level hierarchical structure and manifold geometry calculation to solve the problems of weak geometric perception and lack of interpretability in the prior art.

The invention provides an entanglement-locked expansion protein-based tissue adhesive as well as a preparation method and application thereof. According to the preparation method, a protein structure is destroyed by utilizing a disulfide bond reducing agent to obtain expanded protein with exposed hydrophobic groups, and then the expanded protein is subjected to strong interaction (electrostatic interaction and hydrogen bond) through polyelectrolyte and the expanded protein; the lock unfolds the exposed hydrophobic groups on the surface of the protein to stably expose the hydrophobic groups and lock chain entanglement therebetween. The entangled-locked expanded protein-based tissue adhesive has a stably exposed hydrophobic group, and has the advantages of strong hydrophobic property, strong adhesive force, stable adhesive property, excellent body performance (high storage modulus), good biocompatibility and good degradability. In addition, when the entangled-locked expansion protein-based tissue adhesive is applied to bleeding wounds, the hemostatic effect is achieved, the hemostatic time is remarkably shortened, the wound blood loss amount is remarkably reduced, and the excellent hemostatic plugging effect is achieved.

The invention discloses a screening method of a small molecule STAT3 inhibitor and application of the small molecule STAT3 inhibitor. The screening method comprises the following steps: obtaining an STAT3 protein-small molecule compound crystal structure from a Protein Data Bank database, and carrying out pretreatment on the STAT3 protein-small molecule compound crystal structure; a SiteMap module is adopted to search a protein surface binding pocket, and a pocket at an SH2 structural domain is selected to screen an STAT3 inhibitor; selecting the center of a butt joint box and setting the size of the butt joint box; selecting and downloading a to-be-screened compound library; compound library preprocessing, multi-mode molecular docking and MM / GBSA free energy calculation are performed in sequence in a virtual screening workflow mode, and sorting is performed according to combination free energy values from small to large; and a molecular dynamics simulation method of Binding Pose Metadynamics is adopted for further screening, so that a compound with potential activity is obtained.

The application aims to provide a method and device for constructing a protein sequence prediction model, which comprises: determining corresponding surface point cloud information and sample protein sequence information of a sample protein based on sample protein information, wherein the sample protein information comprises protein sequence information and protein structure information, and sequence information belonging to the surface of the sample protein in the sample protein sequence information is masked; and training a corresponding protein sequence prediction model based on the surface point cloud information and the sample protein sequence information of the sample protein, wherein the protein sequence prediction model comprises a structure encoder, a sequence encoder and a corresponding decoder. In the construction of the protein sequence prediction model, the application introduces information of a protein surface for sequence prediction, which can effectively improve the prediction accuracy of the model and improve the surface accuracy of the predicted protein sequence.

The invention relates to the technical field of chemical fibers, in particular to a modified collagen fiber preparation method which comprises the following steps: S1, preparing collagen modified powder; s2, adding the collagen modified powder and the polymer slices into a screw extruder in proportion, and blending and spinning to obtain nascent fibers; s3, performing post-processing on the nascent fiber to obtain the modified collagen fiber. Polymer slices and collagen modified powder are blended and spun, so that the moisture absorption and conduction performance of the fabric is enhanced, the fabric has antibacterial performance, the hand feeling and skin-friendly performance of the fabric are improved, and the fabric is suitable for skin-attached clothes; according to the invention, the DTBP is chemically crosslinked and grafted on the surface of the collagen, and the DTBP is easily combined with hydrogen atoms on the surface of the collagen to form branched chains when being heated and can be decomposed when being heated during melt extrusion, so that the fluid viscosity is reduced, the interface temperature between the collagen and a polymer is reduced, and the damage to the activity of the collagen in the spinning and melting process can be greatly reduced.

The invention discloses a protein allosteric site identification and determination method and device, and the method comprises the steps: obtaining allosteric site data of protein, the allosteric site data comprising protein 3D structure data and protein amino acid feature data; inputting the allosteric site data into a trained integrated learning model, and scoring and sorting the allosteric site data; and identifying and determining the corresponding position of the allosteric site data with the score higher than a preset value on the protein as the protein allosteric site. According to the method, the information of the amino acid near the cavity on the surface of the protein is introduced, and the integrated learning model is utilized to process the obtained allosteric site data, so that the allosteric site of the protein molecule can be determined more quickly and accurately, the application range is wider, and the efficiency is higher.

The invention provides a pretreatment method for airflow dry enrichment of oil cake protein. The pretreatment method comprises the following steps: 1) carrying out coarse crushing on oil cakes; (2) carrying out ultrasonic-assisted supercritical carbon dioxide extraction degreasing on the coarsely crushed oil cakes; (3) carrying out low-temperature plasma treatment on the degreased oil cake, and modifying protein; and (4) carrying out constant-humidity balance on the oil cakes subjected to low-temperature plasma treatment. Through the steps, residual grease in the cake meal can be effectively removed, the hydrophilicity, dispersity and charge distribution of the surface of protein can be improved, the moisture content of powder can be stabilized, the distribution uniformity can be ensured, and powder agglomeration of oil cake meal protein in the airflow dry-method enrichment process can be inhibited, so that the separation efficiency and the product purity can be remarkably improved. The method is mild in process, high in controllability and suitable for airflow dry enrichment of various oil cake proteins.

The invention discloses a method for increasing the content of soluble protein in soybean milk powder, and belongs to the technical field of soybean product processing. Performing biological enzymolysis; adjusting the ion strength; performing emulsification; and performing low-temperature spray drying. Ultrasonic treatment is carried out in the soybean soaking process, and the dissolution rate of soybean protein can be increased. In the enzymolysis step, neutral protease and papain are added into the pulp for enzymolysis, so that the protein hydrolysis degree can be effectively improved, and the protein dispersion index is further improved. Soybean milk ion strength is adjusted by adding soluble calcium salt, surface charge neutralization of protein is promoted, aggregation and precipitation of the protein are reduced, meanwhile, an emulsifier is added to form a protein-lipid compound, and the solubility of the protein is further enhanced. According to the method, through segmented drying, moisture is rapidly removed in the first-stage drying stage; excessive denaturation of the protein is avoided in the second-stage drying stage, so that the content of soluble protein in the soybean milk powder is effectively increased, and the nitrogen dissolution index reaches up to 87%.