133 results about "Disulphide bonds" patented technology

Bispecific antibody derivatives are disclosed which are comprised of a first region which binds to a first antigen and a second region which binds to a second antigen different from the first antigen. The first and second regions of the bispecific antibody are each stabilized by an additional internal disulfide bridge, and connected by a flexible polypeptide linker. The bispecific antibody is devoid of an Fc portion and is encoded as a single chain-sequence.

The present invention features improved methods of in vitro RNA display to allow reliable expression and selection of scFv antibody molecules from expression libraries. The improved methods, in part, involve the use of mildly reducing conditions, which favor of scFv intra-chain disulphide bond and thus correct folding of the scFv antibody molecules. Although particularly suited to expression and selection of scFv antibody molecules, the methods of the invention are also expedient for in vitro RNA display of all classes of protein.

The present invention provides an isolated protein comprising an immunoglobulin variable region comprising at least two cysteine residues positioned within framework region (FR) 2 and/or at least two cysteine residues positioned within framework region (FR3), wherein if at least two of the cysteine residues in FR2 and/or FR3 are not conjugated to a compound then an intra-framework disulphide bond is capable of forming between the cysteine residues. Preferably the protein comprises an immunoglobulin heavy chain variable region (V_H) and an immunoglobulin light chain variable region (V_L), wherein at least one of the variable regions comprises the two cysteine residues. The present invention also provides conjugates of the protein and another compound.

The invention discloses a shell layer dropping type nanometer medicine carrier preparation based on an amphiphilic block copolymer and a preparation method thereof. The preparation is prepared from the following components in parts by weight: 1 to 20 parts by weight of active ingredient medicines, 10 to 200 parts by weight of amphiphilic block copolymers and 20 to 500 parts by weight of organic solvents. The nanometer medicine micelle carrier preparation is in a core-shell structure, the core of which is a hydrophobic chain segment used for wrapping active ingredients and the shell of which is an amphiphilic block copolymer hydrophilic chain segment, and a hydrophilic segment and a hydrophobic segment in the amphiphilic block copolymer are connected through a disulphide bond S-S. The medicine carrier preparation can be preserved easily and has the advantages of high stability, high medicine cladding ratio, large medicine loading capacity, low toxicity and high medicine bioavailability.

The invention concerns a purified recombinant glycoprotein having the following properties: a) an adherence capacity to CD4; b) an affinity with a anti-gp120 antibody capable of neutralizing in vitro HIV cell infection; c) an affinity with an anti-gp41 antibody; d) a timeric form free from inter-chain disulphide bonds. The invention also concerns a vaccine comprising said purified glycoprotein and an adjuvant. The invention further concerns a method for obtaining said glycoprotein, which consists in expressing, by means of genetic recombining techniques, a glycoprotein corresponding to the properties a), b) and c) mentioned above; purifying it, and subjecting it to steps involving at least a reducing agent, an ionic detergent and/or a neutral detergent in conditions leading to a glycoprotein having said properties.

The invention relates to disulfide-rich peptide molecules which inhibit binding of α4β7 to the mucosal addressin cell adhesion molecule (MAdCAM) in vivo, and show high selectivity against α4β1 binding.

The invention relates to disulfide-rich dimer molecules which inhibit binding of α4β7 to the mucosal addressin cell adhesion molecule (MAdCAM) in vivo, and show high selectivity against α4β1 binding.

The invention discloses an E.tenella protein disulfide linkage isomerase gene EtPDI (Clone ID is BW1-E06,and the Genbank accession number of is EF552214). The gene is connected with a procaryon expression vector pGEX-4T-2; a procaryon expression recombination plasmid pGEX-4T-EtPDI is constructed and is expressed in a colibacillus system; and most of the expressed recombining protein exists in a soluble form. The recombining protein 4T-EtPDI is purified to carry out SPS-PAGE and is transferred to a PVDF film; and antiserum of E.tenella oocyst oral immunized chicken is used as first resistance and goat anti-chicken IgG is used as second resistance to carry out Western-blot analysis, thereby indicating that the gene has certain antigen. The gene is used for preparing an anti-chicken coccidiosis drug and an anti-chicken coccidiosis vaccine.

The invention relates to a polypeptide synthesis method for octreotide acetate. The method comprises the following steps of: taking chloromethyl resin as a starting raw material, preparing a cesium salt from Boc-Thr(tBu)-OH, sequentially connecting amino acids with protecting groups according to a solid-phase synthesis method so as to obtain protected octapeptide resin, meanwhile, removing Boc protecting groups by sequentially using HCl/isopropyl alcohol, carrying out peptide connecting reaction in a manner of taking DIC and HOBT as condensing agents, carrying out reduction by using palladium carbon/hydrogen gas, meanwhile, cutting off peptide chains so as to obtain reduced octreotide, introducing air at the Ph of 7.8-9 so as to cyclize disulfide linkages, then, obtaining a crude octreotide product, and carrying out separation and purification through a C18 column, thereby preparing a fine octreotide acetate product. The method disclosed by the invention has the advantages that threoninol and Fmoc-threoninol are not adopted, the production cost is very low, the method has large-scale production capacity, the process is stable, the raw and auxiliary materials are convenient to obtain, the production cycle is short, the yield of connected peptide is high, the quality is stable, the use of highly-toxic reagents, such as hydrogen fluoride, trifluoroacetic acid and the like, is avoided, and the pollution caused by waste gas, waste water and waste residues is little.

The invention discloses an aspergillus niger alpha-glucosidase aglu<OP> and a high-efficiency expression method of the aspergillus niger alpha-glucosidase aglu<OP> in pichia pastoris. The nucleotide sequence of the optimized alpha-glucosidase gene is shown in SEQ ID No.1. The gene is constructed into a pichia pastoris expression vector, and the pichia pastoris expression vector and disulphide bond isomerase are transformed into the pichia pastoris for co-expression, and the enzyme activity of the alpha-glucosidase gene can be up to 10.1U/mL after induction is carried out for 110 hours in a 3L tank, and is 2.9 times of the enzyme cavity before optimization. The optimized alpha-glucosidase gene can be used for industrial production of the alpha-glucosidase.

The invention relates to the prevention and treatment field of human papillomavirus infection, in particular to an amino acid modification sequence of recombinant human papillomavirus (HPV) L1 capsid protein, a nucleotide sequence encoding the amino acid modification sequence, and a carrier and a transformant containing the nucleotide sequence; and the invention further relates to application of an HPV L1 protein polymer consisting of the amino acid modification sequence to preparing vaccines, pharmaceutical compositions and diagnostic antigen or diagnostic antibodies. In the invention, an HPV L1 protein wild-type sequence is modified to prevent forming of a disulfide bond in the HPV L1 protein, the modification has no significant effect on the structural stability of the recombinant HPV L1 protein, but significantly improves the efficiency of purification process, and directly reduces the reagent consumption, thus effectively lowering the industrial production cost and having great economical benefit.

The present invention addresses limitations of prior art receptor-based traps through a methodology called the clamp/click/cleave (CCC) approach. Two fusion proteins each comprising a binding domain fused to a coiled-coil are non-covalently dimerized through the coiled-coil (clamp), and the dimer so formed is stabilized by a covalent disulphide bond (click) between cysteine residues located on the fusion proteins between the binding domains and coiled-coils. Once the disulphide bond has formed, the coiled-coils are subsequently removed (cleave) by cleaving the fusions proteins at cleavage sites located between the cysteine residues and the coiled-coils to provide the covalently dimerized bivalent binding agent of the present invention. Such binding agents are useful in the treatment and diagnosis of disease states characterized by production and/or overexpression of a ligand to which the binding domains bind. The invention is particularly useful for covalently dimerized receptor-based ligand traps where the binding domains are receptor ligand-binding domains, such as those of TGF-β receptors.