40 results about "Protein surface" patented technology

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 coating a surface of the protein. The protein is modified with a polymerizable double-bond compound. After the loading of the small molecule active ingredient, a polymerization reaction is initiated on the surface of the protein in situ, so that the surface of the protein is coated with a polymer layer. The polymer layer is biologically friendly, and the surface properties of the polymer layer can be regulated and controlled according to the transdermal depth requirement, thereby achieving the targeted transdermal delivery of proteins and active small molecules while breaking through the skin barrier, and significantly overcoming the defect of poor delivery efficiency of previous protein-based delivery systems. The transdermal delivery system has a simple preparation method with a high yield, and thus can be industrially produced on a large scale.

The invention aims to provide a method and equipment for predicting protein complex affinity change caused by mutation, and the method comprises the following steps: utilizing a first sub-network in a twin network to predict protein complex affinity change caused by mutation on the basis of wild type protein complex information and mutation information; determining wild type multi-modal coding information comprising wild type sequence coding information and discretely coded wild type geometric feature coding information; determining affinity information of the wild type through a decoder; determining mutant affinity information through the corresponding second sub-network; and determining affinity change information. By using discrete coding and multi-modal information, the model is helped to cope with the condition that the local structure is not well optimized, so that the model can obtain a more accurate affinity change prediction result by using complex information with low precision. And protein surface information is introduced, so that the model is helped to better learn the influence of a cavity formed by a protein interaction interface on the affinity change, and the affinity change prediction accuracy is further improved.

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 a protein surface oriented imprinting microsphere as well as a preparation method and application thereof, and belongs to the technical field of western blot materials. According to the method provided by the invention, the protein surface imprinting material is successfully prepared by virtue of surface directional imprinting and water-phase polymerization, the stability is high, the interaction force with the protein to be detected is strong, and the target protein can be stably and specifically recognized; according to the protein surface oriented imprinting core-shell microsphere prepared by the method provided by the invention, a base sphere is of a dendritic structure, the diameter is 80nm, the surface has abundant wrinkles and high porosity, a shell layer is a polyion liquid macromonomer polymer layer, target protein is oriented and anchored, and the microsphere has abundant recognition sites, excellent dispersity and high particle size uniformity; the provided preparation method of the protein surface oriented imprinting microspheres is simple and easy to operate, the condition is mild, the used reagent is low in toxicity or non-toxic, no toxic or harmful substance is generated, and the preparation method is environment-friendly.

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.

The invention provides a targeted protein polypeptide design method based on a graph attention network, and aims to solve the problems of low efficiency and insufficient success rate of a traditional method, and the method comprises the following steps: constructing a data set containing 53,717 pairs of protein interaction from an RCSB database, and converting protein surface atoms into a graph structure through feature modeling; designing a hierarchical graph attention network, adopting a multi-head attention mechanism and dynamic edge convolution composite module, and realizing an accurate recognition combination interface through a double-task joint training strategy: hotspot prediction and interaction prediction; in the prediction stage, candidate sequences are screened from 88 and 204 alpha spiral polypeptide libraries through multi-scale surface feature calculation and hotspot region screening and comparison, and through Rosetta energy optimization and three-dimensional visualization verification, the technical problem that the success rate of protein design is insufficient in practical application is solved.

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 invention relates to the field of biochemical detection technology, and particularly relates to a preservation solution for alkaline phosphatase-labeled conjugate and a preparation method thereof. The preservation solution is composed of water and the following components: 10-100 mmol / L buffer salt, 2-20 g / L protein, 0.5-5 g / L surfactant, 0.1-0.5 mol / L salt ion, 0.5-5 g / L preservative, 0.1%-1% protective agent; the protective agent is diglycine. The preservation solution of the present invention can significantly improve the stability of the alkaline phosphatase-labeled conjugate solution during storage and use. At the same time, it can also improve the signal-to-noise ratio of some project tests, thereby reducing the cost of reagent preparation.

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 present invention discloses a preparation method and application of a polyepitope genetically engineered subunit vaccine for porcine Pasteurella multocida, which belongs to the field of genetic engineering in biotechnology. The method comprises: selecting 6 important structural proteins of Pm by literature search, analyzing and screening the sequences of amino acids encoded by the genes of important structural proteins of Pm by bioinformatics analysis software, screening T cell antigen epitopes that can bind to MHC-I / II class molecules and B cell antigen epitopes of peptide or protein surface residues that can bind to antibodies from the screened virulence factors, constructing and synthesizing polyepitope fusion antigen genes and expressing them in Escherichia coli. The antigen epitopes are integrated into a recombinant protein PME and mixed with an adjuvant to obtain a polyepitope genetically engineered subunit vaccine for porcine Pasteurella multocida, which has the advantages of good safety, low cost, ease of use, and easy distinction between infected animals and immune animals, and has good application prospects.

The invention discloses a space state perception-based protein structure-oriented ligand molecule generation method, which comprises the following steps of: realizing boundary perception through a Bayesian flow-based molecule generation framework, and optimizing a primary atomic coordinate of a ligand through a protein surface point cloud; and updating the optimized ligand atom representation through a cross attention mechanism according to a virtual node determined based on the protein atoms, finally constructing a multilevel graph based on the protein atom representation and the optimized ligand atom representation, and modeling and decoding to obtain the atom type and space coordinate of the ligand molecule. According to the method, the defects of an existing structure-based drug design method in the aspects of spatial constraint modeling, multi-layer structure integration and spatial modeling fidelity can be overcome, and the spatial matching performance and the functional adaptability between generated drug molecules and protein targets are effectively improved.

The invention relates to a construction method and application of a heavy metal Cd passivated strain based on protein surface display, Rhodopseudomonas palustris is taken as a host, a surface display technology is adopted, Cd specific binding protein CadR gene from Pseudomonas syringae is fused with a promoter, an anchoring protein, a connecting peptide and a purification tag gene, and the Cd passivated strain is obtained. Introducing into rhodopseudomonas palustris host cells for surface localization expression; the Cd whole-cell adsorbent with the heavy metal passivation function is obtained; the surface display engineering bacterium disclosed by the invention can realize stable and efficient adsorption of Cd < 2 + > in a water body, and has a good application prospect in the field of bioremediation of heavy metal polluted wastewater.

The invention discloses an immobilized alkyl halide dehalogenase, a preparation method thereof, a battery system and a dehalogenation method for catalyzing hydrolysis of halogenated organic matters. The immobilized alkyl halide dehalogenase comprises a carrier and an alkyl halide dehalogenase mutant fixed on the carrier, the carrier is a conductive two-dimensional carbon material of which the surface contains carboxyl; the carbon terminal of the alkyl halide dehalogenase mutant has a cysteine residue, and the cysteine residue is the only cysteine residue on the protein surface; the carrier is connected with the alkyl halide dehalogenase mutant through a connecting agent, and end groups at two ends of the connecting agent are maleimide group and amino group respectively. According to the immobilized alkyl halide dehalogenase and the battery system, the problem of product inhibition caused by halide ion enrichment is solved, and the stability of the enzyme is improved.

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.