34 results about "Disulphide bond formation" patented technology

Transgenic chloroplast technology could provide a viable solution to the production of Insulin-like Growth Factor I (IGF-I), Human Serum Albumin (HSA), or interferons (IFN) because of hyper-expression capabilities, ability to fold and process eukaryotic proteins with disulfide bridges (thereby eliminating the need for expensive post-purification processing). Tobacco is an ideal choice because of its large biomass, ease of scale-up (million seeds per plant), genetic manipulation and impending need to explore alternate uses for this hazardous crop. Therefore, all three human proteins will be expressed as follows: a) Develop recombinant DNA vectors for enhanced expression via tobacco chloroplast genomes b) generate transgenic plants c) characterize transgenic expression of proteins or fusion proteins using molecular and biochemical methods d) large scale purification of therapeutic proteins from transgenic tobacco and comparison of current purification / processing methods in E. coli or yeast e) Characterization and comparison of therapeutic proteins (yield, purity, functionality) produced in yeast or E. coli with transgenic tobacco f) animal testing and pre-clinical trials for effectiveness of the therapeutic proteins. Mass production of affordable vaccines can be achieved by genetically engineering plants to produce recombinant proteins that are candidate vaccine antigens. The B subunits of Enteroxigenic E. coli (LTB) and cholera toxin of Vibrio cholerae (CTB) are examples of such antigens. When the native LTB gene was expressed via the tobacco nuclear genome, LTB accumulated at levels less than 0.01% of the total soluble leaf protein. Production of effective levels of LTB in plants, required extensive codon modification. Amplification of an unmodified CTB coding sequence in chloroplasts, up to 10,000 copies per cell, resulted in the accumulation of up to 4.1% of total soluble tobacco leaf protein as oligomers (about 410 fold higher expression levels than that of the unmodified LTB gene). PCR and Southern blot analyses confirmed stable integration of the CTB gene into the chloroplast genome. Western blot analysis showed that chloroplast synthesized CTB assembled into oligomers and was antigenically identical to purified native CTB. Also, GM1-ganglioside binding assays confirmed that chloroplast synthesized CTB binds to the intestinal membrane receptor of cholera toxin, indicating correct folding and disulfide bond formation within the chloroplast. In contrast to stunted nuclear transgenic plants, chloroplast transgenic plants were morphologically indistinguishable from untransformed plants, when CTB was constitutively expressed. The introduced gene was stably inherited in the subsequent generation as confirmed by PCR and Southern blot analyses. Incrased production of an efficient transmucosal carrier molecule and delivery system, like CTB, in transgenic chloroplasts makes plant based oral vaccines and fusion proteins with CTB needing oral administration a much more practical approach.

Elimination of disulphide bond formation of cysteine-containing S.aureus antigens enhances antigen stability. The invention provides variant forms of cysteine-containing S.aureus antigen with a point mutation that replaces, deletes or modifies the cysteine residue.

An expression system which provides heterologous proteins expressed by a non-native host organism but which have native-protein-like biological activity and / or structure. Disclosed are vectors, expression hosts and methods for expressing the heterologous proteins. The expression system involves co-expression of protein factor(s) which is / are capable of catalyzing disulphide bond formation and desired heterologous protein(s). The expression system is presented using yeast cells as the preferred host, protein disulphide isomerase (PDI) and thioredoxin (TRX) as the preferred examples of the protein factors and HCV-E2715 envelope glycoprotein and human FIGF as the preferred examples of the heterologous proteins.

Elimination of disulphide bond formation of cysteine-containing S. aureus antigens enhances antigen stability. The invention provides variant forms of cysteine-containing S. aureus antigen with a point mutation that replaces, deletes or modifies the cysteine residue.

Elimination of disulphide bond formation ofcysteine-containing S.aureus antigens enhances antigen stability. The invention provides a composition comprising variant forms of cysteine-containing S.aureus antigen with a point mutation that replaces, deletes or modifies the cysteine residue.

The invention provides the molecular degeneration of human growth hormone release hormone (HGHRH) peptides and its di clustering in the treatment of GH deficiency, infertility, dementia, diabetes, and enhanced immunity.The di agent of the present invention is two similar HGHRH -like peptide monomers that contain a single beurine molecular degeneration are connected by a sulfur (sulfurine formed by cysteine, and form an H -shaped structure (internal single ser → CYS inside the molecule → CYSreplace).The present invention also modifies the fatty acid chain of one of the lysine ε‑ amino groups of one of the lysine in the GHRH -like peptide.Extend the GHRH -like peptide monomer or di -polycatus in the body through fatty acid decoration, up to 17 days in the GH in the body.The present invention found that GHRH diodes with long -term activity have AIB → 2 ALA replacement, 18 C‑ 18 C formal sulfur formation, C20 fatty acid chain modification, and C -side amineization structure.

The invention discloses a long-acting recombinant human filaggrin expressed by Saccharomyces cerevisiae and its application. The nucleotide sequence of the long-acting recombinant human filaggrin is shown in Seq ID NO.1. The long-acting recombinant human filaggrin The amino acid sequence corresponding to the nucleotide sequence is shown in Seq ID NO.2. The amino acid sequence of long-acting recombinant human filaggrin includes the amino acid sequence of filaggrin and the amino acid sequence of human serum albumin. The amino acid sequence of filaggrin includes a monomer structure corresponding to the C-terminus of the filaggrin nucleotide sequence repeat amino acid sequence. The long-acting recombinant human filaggrin provided by the invention can promote the aggregation of keratin intermediate filaments and the formation of disulfide bonds between intermediate filaments, prevent the loss of epidermal water and the invasion of external allergic substances, and reduce the apoptosis of epidermal cells induced by ultraviolet rays sensitivity. The fusion of HAS effectively improves the stability of the recombinant protein.

The present invention relates to a kind of amphotericin B albumin nano-preparation and its preparation method and application, wherein through the effect of heating, reducing agent and surfactant, destroy the hydrophobic area of ​​protein and intramolecular disulfide bond, form free thiol-rich Albumin molecules form albumin nanoparticles through the intermolecular disulfide bond network and hydrophobic interaction. In the process of forming the intermolecular disulfide bond network, the small molecule antibacterial drug amphotericin B is introduced to form Protein Nanoformulations. Compared with the prior art, the present invention makes full use of the high binding force between amphotericin B and albumin, transforms its existing deficiencies into advantages, and is expected to exert great application potential in anti-infection therapy, through in vitro and In vivo experiments showed that the nanosystem altered the biodistribution of amphotericin B and reduced drug accumulation in the kidney.

The present invention provides compositions comprising hepatitis C virus (HCV) envelope 2 (E2) polypeptides, including receptor-binding variants, and various uses thereof, wherein the polypeptides are modified to comprise: (i) A cysteine ​​mutated or interrupted at 2, 3 or 4 cysteines from C452, C486, C569, and C597; and, wherein, relative to an HCV E2 polypeptide without cysteine ​​modification, the polypeptide passes Intermolecular disulfide bonds form substantially few multimers and CD81 binding is substantially retained. The present invention provides methods for preparing a composition comprising at least 40%, or at least 45%, or at least 50%, or at least 55%, or at least 60%, or at least 65%, or at least 70% monomeric HCV E2 polypeptide, so The method comprises expressing a polypeptide in a host cell and isolating the expressed product, wherein the polypeptide is an HCV E2 polypeptide including receptor binding variants, and wherein the polypeptide is modified to comprise: (i) a protein selected from the group consisting of C452 Cysteines mutated or interrupted at 2, 3 or 4 cysteines of C486, C569 and C597.

The invention belongs to the technical field of antibacterial agents, and in particular relates to a cyclic polypeptide for resisting Candida albicans and a preparation method thereof. The amino acid sequence of the cyclic polypeptide is shown in SEQ ID NO.1, which is an intramolecular cyclic polypeptide, and an intramolecular disulfide bond is formed between two cysteine ​​residues in its amino acid sequence to form a molecular Inner loop structure, in which the C-terminal end is composed of 8 arginines, the sequence contains two unnatural amino acids, and the proline at the β-turn angle of the polypeptide is replaced with D PRO‑ L PRO to increase stability in beta-turns. The cyclic polypeptide of the invention has simple amino acid sequence structure and convenient synthesis, is used for the prevention and treatment of diseases caused by Candida albicans, and has high antibacterial activity.

The invention relates to a traditional Chinese medicine-magnetic nano-cluster chemoimmunomedicine delivery system and a preparation method thereof, comprising superparamagnetic oxide nanoparticles; the surface of the superparamagnetic oxide nanoparticles anchors drugs and targeting ligands of TAMs; The superparamagnetic oxide nanoparticles form a nano-cluster structure through a disulfide bond; the nano-cluster structure encapsulates proteins. The traditional Chinese medicine-magnetic nanocluster chemoimmunopharmaceutical delivery system of the present invention integrates the targeting advantages of magnetic tendency, ligand modification, and reduction sensitivity, and is a traditional Chinese medicine chemoimmunopharmaceutical delivery system with stable internal circulation, efficient tumor aggregation, and precise targeting of TAMs system.

Elimination of disulphide bond formation of cysteine-containing S. aureus antigens enhances antigen stability. The invention provides variant forms of cysteine-containing S. aureus antigen with a point mutation that replaces, deletes or modifies the cysteine residue.

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 C[mu]3 and C[mu]4 regions of a C[mu] 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.