19 results about "Disulphide bond formation" patented technology

The invention discloses an efficient extraction method of blue fox sperm DNA, and belongs to the technical field of molecular biology. Aiming at the structural characteristics that chromatin of the blue fox sperms is highly condensed, histone is replaced by protamine, and a stable nucleoprotein complex is formed through an intermolecular disulfide bond, the invention provides an efficient DNA extraction method suitable for the blue fox sperms. According to the method, based on the synergistic effect of three chemical reagents, namely SDS, PK and DTT, full lysis of the sperm cells of the blue foxes is achieved, and then efficient enrichment of sperm DNA of the blue foxes can be achieved by combining a conventional DNA extraction method. According to the efficient extraction method of the blue fox sperm DNA provided by the invention, the yield and integrity of the blue fox sperm DNA are remarkably improved, and the limitation that sperm chromatin is difficult to effectively lyse by a conventional method is overcome; the method provides reliable technical support for research on genetic diversity evaluation, population management, molecular breeding and the like of the blue foxes, and has the potential of popularization and application in other high-condensation sperm species.

To provide hepcidin analogs with improved in vivo half-lives, and related pharmaceutical compositions and methods of use thereof.SOLUTION: The present invention relates generally to hepcidin analog peptides and methods of making and using the same. In certain embodiments, hepcidin analogs exhibit one or more hepcidin activities. In certain embodiments, the present invention is directed to hepcidin peptide analogs comprising one or more peptide subunits, wherein the peptide subunits form a cyclized structure via an intramolecular bond, e.g., an intramolecular disulfide bond. In certain embodiments, cyclized structures have increased potency and selectivity compared to non-cyclized hepcidin peptides and analogs thereof. In certain embodiments, the hepcidin analog peptides of the present invention exhibit an extended half-life compared to hepcidin or conventional hepcidin analogs when delivered orally.SELECTED DRAWING: None

The present invention relates to the technical field of bioactive peptides, and particularly relates to an antioxidant peptide based on mussel foot thread, a preparation method, a preparation and its application. The antioxidant peptide is designed and synthesized with reference to the structural characteristics of mussel foot thread proteins mfp-3, mfp-5 and mfp-6, and contains four sequences, namely MFP3-AP1, MFP5-AP2, MFP6-AP3 and MFP-Hybrid. Tyrosine in the peptide is modified to DOPA by enzymatic means, and its stability and activity are enhanced through modifications such as disulfide bond formation, metal ion coordination and PEGylation. The antioxidant peptide has strong DPPH radical scavenging activity, ABTS radical scavenging activity, hydroxyl radical scavenging activity and ferric ion reducing ability, has a protective effect at the cellular level, and can be prepared into liquid preparations, freeze-dried preparations or microcapsule preparations, and is expected to be applied in the fields of antioxidant health products, cosmetics and drugs.

The hybrid Fc proteins of this invention include IgG and IgM Fc components. The IgG Fc component includes at least a portion of a hinge region and CH2 and CHS regions. The IgM component includes Cμ3 and Cμ4 regions of a Cμ constant region. The hybrid Fc proteins can form duplexes by interchain disulfide bonding between cysteines in their hinge regions. The hybrid Fc proteins can be used for treating immune disorders mediated by endogenous IgG, such as those previously treated with intravenous immunoglobulin.

The invention relates to an interference peptide for inhibiting interaction of interferon gene stimulating factors and application of the interference peptide, and belongs to the technical field of biological medicines. The invention designs and synthesizes an interference peptide of a targeted interferon gene stimulating factor, and particularly, the interference peptide is designed as a disulfide bond forming site region of the targeted interferon gene stimulating factor, so that the interaction of the interferon gene stimulating factor can be specifically destroyed; therefore, excessive activation of downstream signals caused by high polymerization of interferon gene stimulating factors can be avoided. The interference peptide disclosed by the invention is combined with an acting surface of a dimerization structural domain mediating oligomerization of the interferon gene stimulating factor to destroy disulfide bond mediated intermolecular interaction, so that excessive activation of the interferon gene stimulating factor caused by virus infection is inhibited, and the purpose of relieving organ injury caused by excessive generation of inflammatory factors in cells is achieved; therefore, effective treatment of clinical virus infection is realized.

The invention discloses a long-acting analgesic fusion protein and application thereof.The analgesic peptide and the C terminal of human serum albumin (HSA) are fused through a flexible linker (GGGGS) n to form the fusion protein, n is 1, 2 or 3, meanwhile, an isolation sequence Pro or Gly-Pro is used for preventing Cys wrong disulfide bond formation so as to effectively mask exogenous epitopes, and therefore the long-acting analgesic fusion protein is obtained. The fusion protein retains the active conformation of the Cys1-Cys10 disulfide bond in the analgesic peptide fragment, and meanwhile, the half-life period is prolonged and the immunogenicity is reduced by using human serum albumin (HSA). According to the fusion protein of the analgesic peptide and the human serum albumin, the plasma half-life period of the human analgesic peptide can be prolonged, and the fusion protein can be used for preparing human analgesic peptide drugs or drugs for treating pains.

The application discloses a kind of cyclic peptide radioactive tracer targeting tumor HER2, labeled precursor and application, it is related to the field of biological medicine.The labeled precursor is A-B-C structure, A is chelating agent, B is connecting arm, C is cyclic peptide compound, the amino acid sequence of cyclic peptide compound is as shown in SEQ ID NO:1, and its 1st cysteine and 10th cysteine form cyclization structure by disulfide bond;Cyclic peptide radioactive tracer includes nuclide and labeled precursor;The application also provides the application of labeled precursor or cyclic peptide radioactive tracer in preparing labeled diagnostic or therapeutic nuclide or HER2 high expression tumor diagnosis and treatment product.The radioactive tracer prepared in the application has good in-vivo stability, has high binding specificity with tumor HER2, has longer tumor retention time, and is simple to synthesize, and has important significance for promoting the clinical application of HER2 targeted polypeptide in nuclear medicine tumor diagnosis and treatment integration.

The invention belongs to the technical field of bioengineering, and particularly relates to a kluyveromyces marxianus engineering strain for efficiently expressing bovine beta-lactoglobulin and application of the kluyveromyces marxianus engineering strain. According to the invention, disulfide bond forming enzyme genes ERO1 and ERV2 of a disulfide bond isomerization pathway of pichia pastoris and disulfide bond isomerase genes PDI1 and MPD1 are introduced into a kluyveromyces marxianus chromosome interface, so that a disulfide bond synthesis pathway is enhanced, and folding of beta-lactoglobulin and formation of disulfide bonds are promoted; the glucose phosphate isomerase gene PGI1 of a glycolytic pathway is knocked out, and NADPH and synthesis of an amino acid precursor are improved; through fermentation condition optimization, the secretory expression beta-lactoglobulin yield of beta-lactoglobulin A and B recombinant expression engineering strains reaches 5.1 g / L and 7.3 g / L. The kluyveromyces marxianus engineering strain is used for preparing two subtypes of beta-lactoglobulins, is high in yield, short in fermentation period and low in cost, and can be applied to the fields of food, nutrient supplements, medical care and the like.

The invention discloses a trichoderma reesei engineering bacterium for producing high-activity lytic polysaccharide monooxygenase as well as a construction method and application of the trichoderma reesei engineering bacterium, and belongs to the technical field of genetic engineering. According to the invention, a Trichoderma reesei endogenous constitutive strong promoter Pcdna1 is adopted to drive transcription of an LPMO gene, and the Trichoderma reesei endogenous constitutive strong promoter Pcdna1 is matched with a terminator Tpdc to construct a complete transcription unit (Pcdna1-lpmo-(GGGGS) 3-pdi2-Tpdc), so that the transcription efficiency of the LPMO is improved; the LPMO and a protein disulfide bond isomerase (PDI) encoding gene pdi2 are subjected to fusion expression through a (GGGGS) 3 flexible connecting peptide, and the PDI-mediated disulfide bond forming ability is utilized to enhance the enzyme activity and secretion efficiency of the LPMO. The activity of the expressed LPMO is remarkably improved, the LPMO and cellulase are cooperated to degrade microcrystalline cellulose, the glucose yield of the cellulase can be improved by 18.5%, and the glucose yield of the cellulase can be improved by 33.1% through fusion expression of LPMO-PDI. The invention provides an innovative technical scheme for producing high-activity LPMO, and is suitable for biomass conversion and industrial enzyme preparation development.

The invention discloses a protein electrostatic spinning fibrous membrane dressing for promoting scar-free healing of wounds. The protein electrostatic spinning fibrous membrane dressing comprises water-soluble globular protein, a disulfide bond reducing agent and a stabilizer (trifluoroethanol, a urea water solution, trifluoroacetic acid and the like). According to the dressing, disulfide bonds of water-soluble globular protein are broken through a disulfide bond reducing agent to form an expanded protein chain, and then the expanded protein chain is stabilized through a stabilizer; electrostatic spinning is carried out by controlling the direct-current voltage between the spray head and the roller receiver rotating at a high speed, the receiving distance and the rotating speed of the roller receiver, and the protein nanofiber membrane dressing with the oriented arrangement structure is prepared. The protein nanofiber membrane dressing inhibits excessive wound contraction by reducing expression of alpha-SMA, promotes wound healing at the same time, and has a remarkable anti-scar effect. The dressing has a wide application prospect in wound treatment, especially in clinical application of pursuing scar-free healing.

The invention discloses a solid-phase synthesis insulin glargine preparation process, which belongs to the technical field of biological pharmacy, and comprises the following steps: S1, carrying out solid-phase synthesis on an insulin A chain through Wang resin, removing a protecting group, and then oxidizing by using NCS to form a first pair of disulfide bonds: sequentially inoculating amino acids according to an Fmoc solid-phase synthesis method by using NCS as an oxidizing agent and Wang resin as a solid-phase carrier, so as to obtain a second pair of disulfide bonds; constructing an A chain sequence; s2, performing solid-phase synthesis of insulin B chain by Wang resin, grafting DTDP after cutting, and purifying; s3, butting the A chain solution and the B chain solution to form a second pair of disulfide bonds; and S4, constructing a third pair of disulfide bonds by adopting an iodine oxidation method. According to the method, disulfide bonds can be directionally formed and constructed in three steps, non-specific crosslinking is avoided through selective oxidation of NCS, DTDP and iodine, correct folding of molecules is ensured, the total yield of the three-step disulfide bond forming process reaches 28% and is increased by 13% compared with one-pot oxidation, and the yield is increased; the process is controllable, and the industrial adaptability is high.

The hybrid Fc protein of the present invention comprises IgG and IgM Fc components. The IgG Fc component comprises at least a portion of the hinge region and the CH2 and CH3 regions. The IgM component comprises the Cμ3 and Cμ4 regions of the Cμ constant region. The hybrid Fc protein can form a duplex through interchain disulfide bonds between cysteines in its hinge region. The hybrid Fc protein can be used to treat immune diseases mediated by endogenous IgG, such as diseases previously treated with intravenous immunoglobulins.

The present invention relates to an interfering peptide that inhibits the interaction of interferon gene stimulator factors and its application, and belongs to the field of biomedicine technology. The present invention designs and synthesizes an interfering peptide that targets interferon gene stimulator factors. Specifically, the interfering peptide is designed to target the disulfide bond formation site region of interferon gene stimulator factors, which can specifically destroy the interaction of interferon gene stimulator factors, thereby avoiding the excessive activation of downstream signals caused by the high polymerization of interferon gene stimulator factors. The interfering peptide of the present invention destroys the intermolecular interaction mediated by disulfide bonds by binding to the action surface of the dimerization domain that mediates the oligomerization of interferon gene stimulator factors, thereby inhibiting the excessive activation of interferon gene stimulator factors caused by viral infection, thereby achieving the purpose of alleviating the excessive production of intracellular inflammatory factors that cause organ damage, thereby achieving effective treatment of clinical viral infections.

The present invention relates to a recombinant library of particles displaying multiple single-chain variable fragments (scFv) against various antigens, such as HER2. The displayed single-chain variable fragments are characterized by improved stability due to non-natural interdomain disulfide bridges at novel positions. The present invention relates to methods for constructing such libraries, their use to obtain stabilized scFv with desired antigen-binding properties, and to such scFv. In some embodiments, the interdomain disulfide bridge is artificially introduced. In further embodiments, the artificially introduced disulfide bridge is formed between a cysteine ​​residue in CDR-H3 at position −4, counting from the conserved tryptophan H103 in FR-H4, and a cysteine ​​residue in CDR-L1 at position L34, according to the Kabat numbering scheme.

The present invention relates to a method for detecting pathogenic strains resistant to carbapenem antibiotics in a biological sample. The present invention directly identifies carbapenem antibiotic-degrading enzymes, particularly KPC, OXA, NDM, IMP, VIM and / or GES proteins, by mass spectrometry, thereby rapidly determining whether a pathogenic strain is resistant to an antibiotic and the type of resistance-related protein. The present invention discovers the physical and chemical properties of each enzyme in vivo, such as the unique N-terminal cleavage length, methionine residue oxidation and disulfide bond formation based on the type of carbapenem-degrading enzyme, and reflects them in reference mass values, and by doing so, the presence of antibiotic-resistant strains can be more thoroughly detected with high reliability. Therefore, this approach can be effectively used to establish an appropriate antibiotic administration strategy at an early stage of infection.

The invention discloses a bicyclic peptide targeting human Nectin-4 protein as well as a preparation method and application of the bicyclic peptide, and belongs to the field of biological medicines. The amino acid sequence of the bicyclic peptide is shown as SEQ ID NO: 1, the bicyclic peptide can be screened through a phage display technology and prepared through a chemical synthesis method, and a stable bicyclic space structure is formed in a molecule through two pairs of disulfide bonds. A surface plasmon resonance technology proves that the bicyclic peptide can be specifically combined with an extracellular domain of human Nectin-4 protein with micromole affinity KD = 1.79 * 10 <-4 > M. The bicyclic peptide provided by the invention has important application value in the aspects of preparing a Nectin-4 protein detection reagent, serving as a tool compound for researching the biological function of Nectin-4 and serving as a lead molecule for developing a diagnostic or therapeutic product of targeted Nectin-4.

This invention provides a method for producing novel antigen-binding molecules that have the activity to regulate interactions between antigen molecules. [Solution] A method for producing an antibody preparation, comprising the steps of contacting an antibody solution with a reducing agent and, following the contact step, re-oxidizing the antibody, wherein the antibody comprises a first antigen-binding domain and a second antigen-binding domain linked to each other by at least one disulfide bond, the at least one disulfide bond being formed between amino acid residues at EU numbering position 191 in the CH1 region of each of the first and second antigen-binding domains, and the antibody solution comprises two structural isoforms of antibodies differing only by the at least one disulfide bond.

The invention discloses a novel immune cell regulatory molecule Novel-1 protein, an anti-Novel-1 monoclonal antibody, Novel-1-Cytokine and application of the novel immune cell regulatory molecule Novel-1 protein, the anti-Novel-1 monoclonal antibody and Novel-1-Cytokine in immune cell separation and treatment. Novel-1 protein is transmembrane protein, an extracellular region has nano-scale ligand binding capacity, and an intracellular region contains an ITAM-like structure to activate an immune signal pathway. The anti-Novel-1 monoclonal antibody is prepared through a hybridoma technology, the affinity KD is 3.5 * 10 <-10 > M, and the purity of Novel-1 + cells sorted by magnetic beads reaches 85%-88.7%. The Novel-1 extracellular domain is specifically bound with the Novel-1 extracellular domain, so that the multiplication time of immune cells is promoted to be shortened to 18.5 hours, and the secretion amount of IFN (interferon)-gamma reaches 1500pg / ml. The in-vitro tumor killing efficiency is improved by 40% or above, the in-vivo tumor inhibition rate is 70%, the lifetime is prolonged by 50%, and no obvious toxic or side effect exists. The invention constructs a high-specificity sorting-directional activation immune cell treatment system, can be widely applied to clinical treatment of tumors such as liver cancer, lung cancer and the like and autoimmune diseases such as rheumatoid arthritis, systemic lupus erythematosus and the like, and has remarkable medical value and wide market application prospect.

The invention provides a cyclic polypeptide and application thereof, the cyclic polypeptide is derived from Blastomyces dermatidis, the amino acid sequence of the cyclic polypeptide is as shown in SEQ ID NO.1, and a cyclic structure is formed through three pairs of disulfide bonds (Cys1-Cys4, Cys2-Cys5 and Cys3-Cys6) in a molecule. The cyclic peptide has multiple functions of resisting gram-positive bacteria (including MRSA), inhibiting inflammatory response and promoting wound healing. The polypeptide has a wide application prospect in the fields of medicines, cosmetics and the like.