58 results about "Protein surface" patented technology

The invention relates to the technical field of protein and peptide, in particular to cubilose peptide with high antioxidant activity and a preparation method of tablets of the cubilose peptide. Comprising the following steps: preparing modified cubilose zymolyte; performing multiple enzymolysis on the modified cubilose zymolyte; the antioxidant stability of the cubilose peptide is enhanced. The resveratrol is grafted on the surface of cubilose protein through free radical reaction of the resveratrol, so that not only can the antioxidant capacity of the cubilose be enhanced, but also the water solubility of the cubilose can be improved, the subsequent enzyme can be better contacted with the cubilose, the enzymolysis efficiency is improved, and the enzymolysis effect is improved. According to the preparation method, cubilose peptide is added into cubilose, reduction of antioxidant activity of the cubilose peptide due to external oxidation factors and too long enzymolysis time is avoided, then the cubilose is subjected to glycosylation modification through chitosan, the dispersion and emulsification stability of the modified cubilose zymolyte can be improved, and the contact area of subsequent enzymes and the modified cubilose zymolyte is increased; the oxidation resistance and the subsequent enzymolysis efficiency are further enhanced.

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 constructing a protein sequence prediction model, and the method comprises the steps: determining surface point cloud information and sample protein sequence information corresponding to corresponding sample protein based on sample protein information, the sample protein information comprises protein sequence information and protein structure information, and sequence information belonging to the surface of a sample protein in the sample protein sequence information is masked; based on the surface point cloud information corresponding to the sample protein and the sample protein sequence information, a corresponding protein sequence prediction model is obtained through training, and the protein sequence prediction model comprises a structure encoder, a sequence encoder and a corresponding decoder. According to the method, the information of the protein surface is introduced in the construction of the protein sequence prediction model for sequence prediction, so that the model prediction accuracy can be effectively improved, and the surface precision of the predicted protein sequence is improved.

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 provides an active component transdermal delivery system based on a protein carrier, which is of a small molecule active component-protein-polymer composite structure and comprises a small molecule active component, a protein loaded with the small molecule active component and a polymer coated on the surface of the protein. After the protein is modified with a polymerizable double-bond compound and loaded with small-molecule active components, the polymerization reaction is initiated in situ on the surface of the protein through the polymerization reaction, the surface of the protein is coated with a polymer protection layer, the polymer protection layer is biologically friendly, and the surface property of the polymer layer can be regulated and controlled according to the transdermal depth requirement; the targeted transdermal delivery of protein and active small molecules is realized while the skin barrier is broken through, and the defect of poor delivery efficiency based on a protein delivery system in the past is remarkably improved. The transdermal delivery system is simple in preparation method and high in yield, and industrial large-scale production can be achieved.

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 invention discloses a B cell epitope on the surface of glyceraldehyde-3-phosphate dehydrogenase protein, a nucleic acid molecule of the B cell epitope and application of the B cell epitope to detection of mycoplasma hyopneumoniae infection. The B cell epitope can be expressed on the surface of an inert carrier S9 thallus in a functional exhibition mode, an LN7-antibody direct-mediated agglutination test detection method established based on the LN7 expressed on the surface of the S9 thallus in the functional exhibition mode is adopted, the LN7 only specifically recognizes a mycoplasma hyopneumoniae infected serum antibody and a vaccine immune serum antibody containing a GAPDH antigen, a specific binding reaction is conducted, and the mycoplasma hyopneumoniae infected serum antibody and the vaccine immune serum antibody containing the GAPDH antigen can be detected. And cross reaction and non-specific binding reaction with other mycoplasma pathogens, porcine respiratory disease pathogen infection serum and vaccine immune serum are avoided. The diagnosis method is expected to become an important technical means for accurate diagnosis of mycoplasma hyopneumoniae infection and monitoring and evaluation of the immune effect of the mycoplasma hyopneumoniae vaccine.

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 discloses a conserved B cell epitope peptide of a riemerella anatipestifer (RA) surface adhesion factor 3-phosphoglyceraldehyde dehydrogenase (GAPDH), a nucleic acid molecule, a recombinant vector and an application of the conserved B cell epitope peptide. Conservative B cell epitope TG12 is inserted into Salmonella pullorum Peg pili, inert carrier bacteria are introduced, and recombinant bacteria capable of functionally expressing and displaying RaGAPDH protein surface conservative B cell epitope peptide are obtained. The conserved B cell epitope expressed and exhibited can specifically recognize and bind duck-derived and goose-derived RA-infected serum, and macroscopic agglutination reaction particles are observed and have no cross agglutination reaction with other pathogen-infected positive serum. The agglutination detection method has the advantages of specificity, convenience and the like, and is expected to provide a new thought and method for detection, prevention and control of RA infection.

The present invention relates to the field of animal feed technology, and in particular to a pet food that is easily digestible and absorbable and a preparation process thereof. The preparation process comprises the following steps: preparing a chitin nanofiber suspension; preparing a modified pig liver protein solution; preparing a digestive aid additive; and preparing a pet food that is easily digestible and absorbable. The present invention improves the solubility of pig liver protein in water and makes it easier to disperse by grafting maleic anhydride onto pig liver protein. Pig liver protein is rich in high-quality protein. For pets, excessive high-quality protein is not easy to absorb, but will result in overnutrition. After pig liver protein is grafted with maleic anhydride, the surface properties of the protein are changed, which can better improve the absorption rate of organisms. In addition, the introduction of maleic anhydride can reduce the protein content in the modified pig liver protein solution, so that the protein content in the prepared pet food is within the range that the pet can absorb, and the prepared pet food is easy to digest and absorb.

The invention relates to a method and kit for cooperatively detecting tetracycline antibiotics in a water body based on a multi-factor microenvironment, and belongs to the field of chemical substance detection.The method comprises the steps that a carbon quantum dot probe solution and a multi-factor microenvironment solution are mixed, and a detection solution is obtained; mixing the detection solution and a to-be-detected object in a buffer solution to obtain a mixed solution, and detecting the mixed solution through a fluorescence spectrophotometer; wherein microenvironment factors in the multi-factor microenvironment solution comprise one or a combination of more of metal ions, protein and a surfactant; the tetracycline antibiotics comprise one or a combination of more of tetracycline, oxytetracycline, aureomycin and doxycycline. The multi-factor microenvironment substance is introduced and combined with the carbon quantum dot probe to detect the tetracycline antibiotics, so that the response speed is high, and the detection sensitivity and the anti-interference capability are further improved.

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 invention relates to metal ion induced protein nanoparticles and application thereof in vaccine preparation. The protein nanoparticles are formed by self-assembly of protein monomers through induction of the protein monomers by metal ions, and combination of the protein monomers and the metal ions is achieved through amino acid on the surface of protein. According to the application, the capability of the Cage-i53-Zn1-HEHE-5 protein nanoparticles for simultaneously displaying a plurality of protein antigens is proved by taking the Cage-i53-Zn1-HEHE-5 protein nanoparticles as an example. On the basis, more types of protein monomers reversibly combined with metal ions are further designed, and nanoparticles formed by self-assembly of the protein monomers under induction of the metal ions have wide application prospects in vaccine development.

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 relates to the technical field of biological detection, in particular to a detection reagent for biological analysis, a kit and application, the detection reagent comprises a regulating medium, and the regulating medium comprises a buffer system. Through innovative component combination and formula optimization, non-specific adsorption is reduced, the signal-to-noise ratio is increased, the detection sensitivity is improved, particularly, a specific amino acid buffer solution is introduced, the specific amino acid buffer solution can interact with a hydrophobic region on the surface of protein, non-specific adsorption components are reduced, and the biological analysis and detection performance can be remarkably improved.

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.