198 results about "Surface protein" patented technology

The invention provides a subunit fusion protein RBD-Fc on the surface of a porcine D-type coronavirus and a preparation method and application thereof, the preparation method comprises the following steps: 1) cloning a gene sequence as shown in SEQ ID NO.5 into a eukaryotic expression vector to obtain a recombinant plasmid containing a fusion protein RBD-Fc coding gene; (2) transfecting a recombinant plasmid containing the fusion protein RBD-Fc coding gene into an expression cell; 3) culturing, screening and domesticating the expression cells in the step 2) to obtain a highly expressed cell strain; and 4) fermenting and culturing the cell strain in the step 3), and purifying to obtain the subunit fusion protein RBD-Fc. According to the present invention, the RBD-Fc can be subjected to mass soluble expression, the protein is stable, the problems that the porcine D-coronavirus surface S protein cannot be subjected to large-scale expression and the like in the prior art are solved, the preparation method is simple, and the cost is low.

Provided herein are exosomes (such as modified exosomes) that include or express one or more surface proteins that are covalently linked to an immunomodulatory molecule or a therapeutic molecule. In particular examples, the exosomes are from a cancer cell, a stem cell, or an immune cell. Also provided are methods of making and using the modified exosomes, for example for treating cancer.

The invention relates to an extracellular vesicle surface protein detection paper-based kit and application thereof, and belongs to the technical field of biology. The technical problems that an existing sEVs detection technology is insufficient in specificity, depends on professional instruments and cannot meet the instant detection requirement are solved. According to the method, sEVs are synergistically captured through double aptamers, the target specificity is improved, signals are amplified in a cascaded mode through hyper-branched rolling circle amplification (HRCA) and a CRISPR / Cas12a system, and visual detection is achieved by detecting FAM-biotin probe separation before and after cutting through a transverse flow test strip. According to the method, interference of free protein is effectively avoided through double-target recognition, and the detection limit is as low as 406 parts / mL; cRISPR and a paper-based technology are combined to realize high sensitivity and instant detection; the system is simple and convenient to operate, does not need professional instruments, is suitable for tumor diagnosis and treatment monitoring of clinical samples, and provides a portable solution for precise medical treatment.

The invention provides a polypeptide, and the sequence of the polypeptide is AEDVGDVAFVKNDT. The polypeptide provided by the invention can inhibit the human respiratory syncytial virus surface protein F so as to inhibit the fusion of the human respiratory syncytial virus surface protein F and a host cell membrane. The invention also provides the sheep colostrum. The sheep colostrum comprises the polypeptide with the antiviral function, so that the sheep colostrum is helpful for old people with relatively weak resistance to resist infection of human respiratory syncytial viruses and promotes repair of respiratory mucosa. The invention also provides a preparation method of the sheep colostrum. The preparation method is simple and can be used for industrial production. The invention also provides a preparation method of the polypeptide.

Compositions comprising aptamers capable of specifically binding to a surface protein of Clostridium difficile spore are provided. A method for detecting, enriching, separating, and / or isolating Clostridium difficile spores is provided.

The invention discloses an extracellular vesicle detection method based on magnetic bead capture and nano-enzyme labeling, used Fe3O4 (at) TiO2 magnetic beads can be used for rapidly enriching small extracellular vesicles (sEVs), meanwhile, the integrity of surface proteins of the sEVs is reserved, and a high-quality sample is provided for subsequent detection and analysis; the used nano enzyme has good oxidase-like activity, no exogenous hydrogen peroxide (H2O2) is needed, errors caused by addition of exogenous substances are reduced, and the detection sensitivity and accuracy are improved. The invention breaks through the bottlenecks of insufficient sensitivity (the detection limit reaches 102 pieces / mu L) and obvious environmental interference in the traditional detection method, and can also provide a new idea and technical scheme for monitoring extracellular vesicle markers of diseases such as tumors and the like.

The invention relates to a method to determine a homology directed repair (HDR) event within a eukaryotic cell, wherein the cell expresses a first isoform of a surface protein, which is different from a second isoform of said surface protein with regard to an amino acid marker. The method comprises the steps of inducing a DNA double strand break, providing a HDR template DNA construct comprising the amino acid marker corresponding to the second isoform of the surface protein and subsequently determining the expression of the first or second isoform of said surface protein on said cell, wherein expression of the second isoform indicates a successful HDR event. The invention also relates to a method for editing a genomic location of interest within a eukaryotic cell, and to a method of selectively depleting or enriching an edited cell in a composition of non-edited and edited cells.

The invention discloses a method for separating and detecting new intestinal bacterial exovesicles, which comprises the following steps: (1) carrying out metabolism labeling on microorganisms to be researched by an azido-modified hydrochloric acid D-type amino acid metabolism marker, so that the new intestinal bacterial exovesicles carry azido groups; (2) separating and extracting the bacterial exovesicles from a sample containing the bacterial exovesicles; (3) adding a capture connector capable of reacting with an azide group into the extracted bacterial outer vesicles; and (4) separating, capturing and detecting the bacterial outer vesicles obtained in the step (3) by adopting a micro-fluidic chip, wherein the obtained bacterial outer vesicles are newborn bacterial outer vesicles. The method disclosed by the invention can selectively capture the newborn bacterial exovesicles from the sample under the condition of not influencing surface protein expression of the bacterial exovesicles so as to carry out downstream analysis on the newborn bacterial exovesicles of the intestinal flora.

The invention relates to the technical field of cell analysis, and discloses a cell analysis method, a cell analysis device and a storage medium, and the method comprises the following steps: S1, multi-modal labeling: synchronously loading cell surface protein, a metabolism probe and a spatial positioning marker; s2, collaborative acquisition: obtaining space-time multi-dimensional data through flow type, mass spectrum and two-photon combination; s3, tensor modeling: constructing four-dimensional data and correcting spatial drift; s4, metabolic constraint decomposition: executing non-negative tensor decomposition to obtain a factor matrix; s5, dynamically adjusting parameters: optimizing excitation and sampling frequencies in real time according to factor changes; and S6, feature analysis: calculating a metabolism-phenotype coupling index. Through a multi-modal synchronous marking and four-dimensional dynamic tensor modeling method, cross-dimensional association of physical characteristics, molecular expression and metabolic activity is broken through, lossless fusion of single-cell multi-dimensional data is realized, and the spatial resolution is greatly improved compared with the prior art.

The present invention provides a dual DNA tetrahedron structure, a preparation method and an application thereof. The dual DNA tetrahedron of the present invention includes a first DNA tetrahedron structure, a second DNA tetrahedron structure and a connecting chain. This structure can specifically recognize two cell surface proteins and be labeled by fluorescence; at the same time, due to the steric hindrance effect of the structure, it is difficult for the two proteins to approach each other, affecting the interaction between the two. This structure can exist on the cell surface for a long time, thus having a good cell regulation effect on these two cell membrane surface proteins, specifically reflected in reducing the phosphorylation level of HER2 protein, promoting the expression of apoptosis-related proteins, and ultimately leading to apoptosis of tumor cells and reducing the cell activity of tumor cells.

The present invention relates to specific monoclonal antibodies and their applications. The amino acid sequence of the light chain CDR1 of the monoclonal antibody is shown in SEQ ID No. 1, the amino acid sequence of CDR2 is shown in SEQ ID No. 2, and the amino acid sequence of CDR3 is shown in SEQ ID No. 3; the amino acid sequence of the heavy chain CDR1 of the monoclonal antibody is shown in SEQ ID No. 4, the amino acid sequence of CDR2 is shown in SEQ ID No. 5, and the amino acid sequence of CDR3 is shown in SEQ ID No. 6. The present invention uses recombinant monkeypox virus surface protein E8L as an antigen. The screened monoclonal antibodies have good affinity for the recombinant monkeypox virus surface protein E8L at the molecular and cellular levels, can significantly inhibit the infection efficiency of VACV replication-deficient strains in VERO cells, and have good in vitro neutralization effect against monkeypox virus.

The application discloses a kind of fowl secretory bacterium surface proteins and its screening method and application, belong to biotechnology field.The application can be soluble high-efficiency expression in escherichia coli by screening protective antigen from fowl secretory bacterium heparin binding protein, combined with antigen prediction, soluble analysis and structure-oriented protein design, successfully obtained protein A0A3Q9GGY1, A0A3S9QKJ0 and six-site mutant PLO that can be soluble high-efficiency expression in escherichia coli, has good immunoprotective efficiency, and has accumulated experience for the screening and design of high-yield antigen, and has laid a foundation for the research and development of fowl secretory bacterium vaccine.

Providing nucleic acid constructs that enhance antigen-specific immune responses against enveloped viruses. [Solution] A nucleic acid construct comprising a polynucleotide encoding a SNARE protein selected from the group consisting of VAMP7, STX7, GOSR1, and SEC22B, and a polynucleotide encoding a surface protein antigen of an enveloped virus.

The invention discloses an exosome metabolic fingerprint extraction and surface protein quantification integrated detection method based on a porous magnetic nano assembly material. The preparation method comprises the following steps: firstly, preparing a porous magnetic nano assembly material Fe3O4 (at) SiO2-Apt-Au, and modifying the surface of a SiO2 shell layer with an exosome surface protein aptamer; au nanoparticles serve as an LDI-MS mass label, the surface of the Au nanoparticles is connected with an antisense strand of the aptamer, and the Au nanoparticles are connected with the Fe3O4 (at) SiO2 magnetic nanoparticles through complementary pairing with a base of the aptamer. In exosome metabolism detection, the nano assembly material can play the roles of exosome capture and LDI-MS auxiliary enhancement of a matrix; a strand displacement reaction site and an LDI-MS mass tag are provided; by combining LDI-MS as a downstream analysis tool, high-sensitivity, high-resolution, low-sample-consumption, high-throughput, rapid and low-cost exosome metabolic fingerprint extraction and surface protein quantitative analysis can be realized.

The present invention relates to a preparation method and application of a surface protein imprinted polymer relying on an enzyme cascade reaction; the surface imprinted polymer is prepared under conditions of high monomer concentration by mediating local free radical polymerization through an enzyme cascade reaction. The local free radical polymerization reaction is initiated by an initiation system consisting of GOx / HRP, acetylacetone and glucose fixed on the surface of a nanocarrier, so that the polymerization reaction proceeds around the surface of the nanocarrier. The random freedom of free radicals in the entire solution is avoided, and even at high monomer concentrations, no agglomeration phenomenon occurs during polymerization. At the same time, the method is carried out under conditions of high monomer concentration, which is conducive to the sufficient pre-assembly of functional monomers and template proteins, thereby improving the imprinting efficiency. The imprinting capacity of the synthesized nanoimprinted microspheres for lysozyme is 145.3 mg g ‑1 , the imprinting factor is 14.2.

The application belongs to the technical field of biological medicine, and particularly discloses application of Lactobacillus delbrueckii surface protein DUF4430 in preparation of a medicine for improving symptoms of ulcerative colitis, and preventing and / or treating ulcerative colitis. The application provides a new use of the Lactobacillus delbrueckii surface protein DUF4430, including application in preparation of a medicine for improving symptoms of ulcerative colitis, and preventing and / or treating ulcerative colitis. Animal experiments show that the Lactobacillus delbrueckii surface protein DUF4430 can relieve DSS-induced ulcerative colitis in mice, improve weight loss, shorten colon length, and reduce colon mucosal injury, reduce the content of pro-inflammatory cytokines (such as IL-1β and IL-6) in the colon, increase the content of anti-inflammatory cytokines (such as IL-10), reduce the proportion of pro-inflammatory macrophages in the spleen and colon, and inhibit the pro-inflammatory phenotype of macrophages, and therefore can be used for preparing a medicine for improving symptoms of ulcerative colitis, and preventing and treating ulcerative colitis.

A hybrid protein comprises a first domain comprising a sequence encoding a surface protein of an enveloped RNA virus and a second domain comprising a sequence encoding an ectodomain of a type 2 transmembrane domain protein, wherein the second domain is located at the C-terminal of the first domain. The hybrid protein or an mRNA encoding such protein can be used as a vaccine against the infection of the enveloped RNA virus.

The invention discloses a preparation method of a Ca (OH) 2 activated fish scale-based adsorbent, and relates to the technical field of functional materials. Comprising the following steps: 1, pretreating fish scales: carrying out acid treatment on the cleaned and dried fish scales to obtain fish scales without surface protein, carrying out alkali treatment on the fish scales to obtain fish scale slurry, drying the fish scale slurry to obtain fish scale powder, and 2, dissolving the fish scale powder and Ca (OH) 2 in water according to a mass ratio of the fish scale powder to Ca (OH) 2 of 1: 3-3: 1, adding pyrrole, fully mixing, and carrying out drying to obtain the fish scale powder. The mass volume ratio of the fish scale powder to pyrrole is (1: 8)-(1: 2), and the volume ratio of pyrrole to the potassium persulfate aqueous solution is (3: 20)-(3: 5), and step 3, carrying out suction filtration and solid-liquid separation on the composite product, repeatedly washing to be neutral, and drying to obtain the polypyrrole composite Ca (OH) 2 activated fish scale-based adsorbent.

Provided are an antigen-binding protein neutralizing respiratory syncytial virus (RSV) and a use thereof. The antigen-binding protein comprises a single-domain antibody containing CDR1, CDR2, and CDR3 antigen complementarity-determining regions, and has the function of exerting virus-neutralizing activity by recognizing and binding to RSV surface proteins. The antigen-binding protein can prevent or treat diseases caused by RSV infection.

The invention provides a method for identifying breast cancer subtypes through exosome surface markers, and belongs to the technical field of exosome surface marker detection.The method includes the steps that multicolor fluorescence markers are adopted for CD9, CD63, CD81 and breast cancer subtype related surface proteins, a multidimensional fluorescence intensity matrix is constructed through flow cytometry, and the breast cancer subtypes are identified through the multidimensional fluorescence intensity matrix; and the interaction strength between the markers is analyzed by combining a fluorescence resonance energy transfer technology. K-means clustering is adopted to determine different subtype fluorescence characteristic modes, Mahalanobis distance is calculated to quantify difference between subtypes, contour coefficients and cohesion are evaluated to screen an optimal marker combination, an entropy weight method is applied to determine marker weight coefficients, a support vector machine classification model is constructed, and finally, the distance score between a sample to be detected and the clustering center of each subtype is calculated to determine the subtype fluorescence characteristic mode. The breast cancer subtype is accurately judged based on the minimum distance principle, and an important basis is provided for clinical individualized diagnosis and treatment.

A cell exosome, which contains, on the membrane surface thereof, one or more phospholipids of a high-fluidity liposome and a surface protein of a cancer cell.

A method for enhancing the immunogenicity of protein / peptide antigens, which comprises conjugating the protein / peptide antigen with a sugar to form a glyco-protein / peptide antigen conjugate, whose immunogenicity is enhanced compared to the unconjugated protein / peptide antigen. Specifically, it involves conjugating a pathogen, such as a viral surface protein antigen or a fragment thereof, with a polysaccharide, especially the capsular polysaccharide of Streptococcus pneumoniae. The conjugate with enhanced immunogenicity can be used for preventing or treating diseases caused by pathogens, especially diseases caused by coronaviruses.

The invention relates to an application of a cerium oxide nano-material in a vaccine adjuvant and / or a vaccine inactivator, in particular to a vaccine, when the cerium oxide nano-material is the vaccine adjuvant, the vaccine comprises the vaccine adjuvant and an immunogen; or when the cerium oxide nano material is a vaccine inactivating agent, the vaccine is a composite vaccine, the composite vaccine comprises the vaccine inactivating agent and a virus, and the virus is embedded in the cerium oxide nano material; the preparation method of the composite vaccine comprises the step of mineralizing and inactivating viruses by using a vaccine inactivator, wherein the vaccine inactivator is cerium salt. The cerium oxide can be used as a vaccine adjuvant and also can be used as a virus inactivator. The maturation of dendritic cells and macrophages can be promoted by means of regulating the level of active oxygen in immune cells and the like, and the antigen presentation efficiency is improved, so that the vaccine-induced body fluid and cellular immune response is enhanced; meanwhile, cerium salt can directly act on virus surface protein for mineralization, efficient and safe virus inactivation is achieved, and preparation of inactivated vaccines is facilitated.

The technology proposed herein concerns a vaccine formulation comprising a) an antigen comprising an amino acid sequence having at least 90% sequence identity with the amino acid sequence of the N-terminal region of a first group B Streptococcus surface protein, and b) a buffer having a pH of 6 to 8 and comprising: a. aluminum hydroxide gel particles, and b. a buffer system comprising: i. 1-3 mM phosphate and 100-200 mM NaCl, or ii. 5-15 mM histidine and 200-400 mM sorbitol. The technology proposed herein further concerns a method of producing a vaccine formulation as well as a vaccine formulation for use in a method of reducing, preventing and / or treating a GBS infection.

The invention relates to a microfluidic device. Said device has at least one magnetic marker, which is designed to bind to surface proteins of cells (30, 31), at least one mixing region, which is designed to bring the at least one magnetic marker into contact with the cells (30, 31), and at least one separating region (14), into which the cells (30, 31) can be introduced and which has at least one magnet (15), preferably on an upper side (16). A method for separating cells by means of the microfluidic device comprises bringing cells (30, 31) into contact with at least one magnetic marker in the mixing region, sedimenting the cells (30, 31) in the separating region (14), applying a magnetic field in the separating region (14), and discharging cells (31) marked with the marker from the separating region by means of a fluid flow (61).

The invention relates to a polypeptide for targeted destruction of lipid droplets and application of the polypeptide in preparation of antitumor drugs, and belongs to the technical field of biological drug manufacturing. In order to solve the problem that an existing anti-tumor drug aiming at tumor lipid droplets cannot effectively inhibit immune escape of tumor cells while destroying the lipid droplets, the invention provides a polypeptide for targeted destruction of the lipid droplets, and the polypeptide comprises a PLIN2 targeted peptide fragment, a self-assembly peptide fragment, an enzyme response peptide fragment and an HLA-E targeted peptide fragment which are connected in sequence. On the basis of a double-targeting strategy, the polypeptide for targeted destruction of the lipid droplets is constructed, and the polypeptide can target the PLIN2 protein on the surfaces of the lipid droplets; the self-assembled peptide fragment can form a nanofiber structure on the surface of the lipid droplet, the structure and function of the lipid droplet are destroyed, endoplasmic reticulum stress is caused, and tumor cell immunogenicity death is caused. The HLA-E targeting peptide fragment released by polypeptide digestion can specifically target HLA-E on a tumor cell membrane, block an NKG2A-HLA-E pathway, and effectively inhibit immune escape of tumor cells.

The application discloses a kind of biological immobilized enzyme based on yeast surface display technology and the application of synthesis 2-phenylethanol, using yeast surface display technology, for the first time with Saccharomyces cerevisiae surface protein a-lectin as anchor protein, the key enzyme (transaminase, decarboxylase, ethanol dehydrogenase) involved in 2-PE producing Ehrlich pathway in Saccharomyces cerevisiae is separately or jointly carried out biological fixation, enhance substrate channel effect and proximity effect, in vitro one-step catalysis L-phenylalanine synthesis 2-PE, provide yield.The method for fixing multiple enzymes of Ehrlich pathway in the application can be used to reconfigure the biosynthesis pathway of other natural products in vitro, to provide feasible scheme for the rational design of cell factory.

This invention discloses a kit for in vitro quantitative detection of hepatitis B virus large surface protein (LHBS). This kit includes multiple monoclonal antibodies, each with its own binding specificity to specific regions of LHBS, thereby improving the sensitivity and dynamic range of LHBS detection in biological samples. Secondly, this invention also provides a set of biological markers targeting specific regions of LHBS, and the monoclonal antibodies can specifically identify this set of biomarkers, enabling non-invasive analysis of HBV infection stages and liver cancer prognosis in biological samples. Furthermore, this invention also provides a set of monoclonal antibodies that, by detecting biomarkers in desired subjects, can predict, diagnose, or treat chronic liver disease.

The invention discloses arcanobacterium pyogenes surface protein as well as a screening method and application thereof, and belongs to the technical field of biology. According to the invention, a protective antigen which can be soluble and efficiently expressed in escherichia coli is screened from arcanobacterium pyogenes heparin binding protein, and antigen prediction, solubility analysis and structure-oriented protein design are combined; proteins A0A3Q9GGY1, A0A3S9QKJ0 and a six-site mutant PLO which can be soluble and efficiently expressed in escherichia coli and have good immune protection efficacy are successfully obtained, experience is accumulated for screening and design of high-yield antigens, and a foundation is laid for research and development of arcanobacterium pyogenes vaccines.

This invention discloses a single-chain antibody against the S1 protein on the surface of SARS-CoV-2, comprising a heavy chain sequence and a light chain sequence. The invention also discloses a gene encoding the above sequence, a recombinant vector containing the above gene, a host cell containing the above vector, a biological agent containing the above antibody, and the application of the above antibody against SARS-CoV-2. This effectively solves the problem of a lack of highly potent antibodies against SARS-CoV-2.