989 results about "Disulfide bonding" patented technology

Disclosed are methods of producing eukaryotic disulfide bond-containing polypeptides in bacterial hosts, and compositions resulting therefrom. Co-expression of a eukaryotic foldase and a disulfide bond-containing polypeptide in a bacterial host cell is demonstrated. In particular embodiments, the methods have been used to produce mammalian pancreatic trypsin inhibitor and tissue plasminogen activator (tPA) in soluble, biologically-active forms, which are isolatable from the bacterial periplasm. Also disclosed are expression systems, recombinant vectors, and transformed host cells.

Disclosed are methods and compositions for producing heterologous disulfide bond containing polypeptides in bacterial cells. In preferred embodiments the methods involve co-expression of a prokaryotic disulfide isomerase, such as DsbC or DsbG and a gene encoding a recombinant eukaryotic polypeptide. Exemplary polypeptides disclosed include tissue plasminogen activator.

The present invention relates to a self-molding permanent agent and a method for proceeding free-rod and free-band type permanent, more particularly to a self-molding permanent agent comprising (a) a reducing composition containing a reducing agent reducing a disulfide bond of cystine on the hair and a molding stimulant spontaneously molding to fix a hair design; (b) a molding composition inducing to mold after reacting with the molding stimulant; and (c) a softening composition releasing the action of a molding stimulant, and a method for pressing a free-rod and free-band type permanent, which overcomes a disadvantage in the conventional method for pressing a permanent that needs to wear a curling device such as rods for a permanent (perm rod) or rubber band and improves to apply a wave set without a hair-curling device for a short time, since it has a self-molding feature.

Compositions, kits, and methods for repairing bonds, for example, disulfide bonds, in hair or on the skin are disclosed. The compositions provide improved conditioning benefit for dry hair or moisturize the skin. The compositions also provide a long lasting moisturized feel and smooth feel to the skin or hair, without feeling greasy. The compositions contain one or more compounds that covalently crosslink at least two thiol groups in the hair or on the skin. Use of the crosslinking compositions prevents reversion of the repaired bonds to their reduced (thiol) state, for at least one week, one month, six months, or one year, after a single application of the composition. Improved methods of styling hair, for example permanent hair waving, hair curling, and hair straightening are also provided.

A single chain T cell receptor (scTCR) comprising an a segment constituted by a TCR α chain variable region sequence fused to the N terminus of a TCR α chain constant region extracellular sequence, a β segment constituted by a TCR β chain variable region fused to the N terminus of a TCR β chain constant region extracellular sequence, and a linker sequence linking the C terminus of the a segment to the N terminus of the β segment, or vice versa, the constant region extracellular sequences of the α and β segments being linked by a disulfide bond, the length of the linker sequence and the position of the disulfide bond being such that the variable region sequences of the α and β segments are mutually orientated substantially as in native αβ T cell receptors. Complexes of two or more such scTCRs, and use of the scTCRs in therapy and in various screening applications are also disclosed.

The invention discloses a preparation method and an application of sulfhydryl/disulfide bond controllable self-crosslinked hyaluronic acid hydrogel and belongs to the field of biological materials. The hydrogel is prepared from a sulfhydryl-hyaluronic acid compound with free sulfhydryl as a raw material; by adjusting the sulfhydryl density (10-60%), the gel temperature (4-37 DEG C) and the molecular weight (0.1M, 0.3M and 1M) of hyaluronic acid, and using the oxidation-reduction transformation characteristics between sulfhydryl and disulfide bonds to control the forming time, degradation time and the mechanical properties of the gel, a controllable and injectable type intelligent hydrogel with a good three-dimensional network crosslinked structure is constructed. Meanwhile, the hydrogel of the type is single in component, avoids the introduction of exogenous toxic substances before and after gel forming, and has good biocompatibility and degradation performance. Based on the research discovery, the controllable self-crosslinked high-polymer polymer can be applied to minimally invasive repairing of tissue engineering in-situ damages and construction of an intelligent adjustable three-dimensional cell culture scaffold.

The invention relates to a chitosan modified alginate hydrogel three-dimensional porous bracket with specific in-vitro degradability and a preparation method thereof. The method comprises the following steps: dissolving sodium alga acid serving as a raw material in phosphate buffer solution; performing amidation reaction of a carboxyl group in the sodium alga acid and an amino group in a cross-linking agent cystamine or dimethyl cystinate under the activation of water-soluble carbodiimide to form a chemically crosslinked hydrogel; performing freeze drying on the hydrogel to obtain a porous bracket material of the hydrogel; and performing surface modification on the porous bracket by using chitosan. In solution of a reducing agent such as cysteine with an appropriate concentration, a disulfide bond in a hydrogel cross-bridge is degraded through a disulfide bond-sulfydryl conversion reaction, so the porous bracket is decomposed and dissolved and disappears. Therefore, the porous bracket can be used as an in-vitro cell culture template material. The hydrogel porous bracket researched by the invention has the characteristics of simple preparation, rich raw material source, low cost and availability. Various physiochemical performances, mechanical strength, degradation rate and surface properties of the bracket material are controllable within a large range.

The invention relates to a quantitative detection method for thermal-denaturation and non-denaturation bovine alpha-lactalbumin in milk and milk products by applying an enzymolysis-liquid chromatography and mass spectrometry combination technology. The quantitative detection method comprises the steps as follows: taking a certain amount of milk or milk samples, dissolving and diluting the milk or milk samples in water to obtain solution with total protein content being about 1mg/mL; after volume metering, correctly sucking 500 mu L, adding an internal standard substance, reacting disulfide bond with dithiothreitol (DTT), alkylating to protect sulfydryl produced in reaction by iodoacetamide (IAA), and then conducting constant-temperature and constant-time enzymolysis with trypsin; and separating enzymolysis products by reversed phase liquid chromatography, conducting detection with a mass spectrum multiple reaction monitoring (MRM) manner, and calculating the result by an internal standard method. The quantitation limit of the method is 0.001g/100g; when adding amount is 0.2, 1.7 and 5.0g/100g, the recovery rate is 98.9-110.8% (n is equal to 6) and repeatability: RSD (Relative Standard Deviation) is smaller than 7.6%; and the quantitative detection method can be applicable to the quantitative detection of samples with different contents of bovine alpha-lactalbumin.

The invention discloses a glucagon like peptide(GLP)-1 mutant polypeptide and a preparation method, a medicinal composition and use thereof. The mutant polypeptide is formed by bonding a Cys-containing elongation peptide to the N terminal of the glucagon like peptide-1 mutant, the mutant polypeptide itself folds to form a disulfide bond. The glucagon like peptide-1 mutant polypeptide is used for preparing a medicinal composition for treating diabetes and treating and preventing obesity. For overcoming the drawbacks of short retention time in body and need of daily injection administration of clinic GLP-1 analogue, the invention provides the GLP-1 analogue which has a longer half-life period. With the longer half-life period, the GLP-1 mutant polypeptide is not required to be injected into a patient every day, and can increase the obedience of the patient effectively.

The invention discloses barrel-shaped alpha conantokin Bt1.3 and application thereof. The amino acid sequence of the barrel-shaped alpha conantokin Bt1.3 is a sequence 2 in a sequence table; and the nucleotide sequence of a coding gene of the conatokin is a sequence 1 in the sequence table. The connection modes of a disulfide bond of the conantokin are Cys1-Cys3 and Cys2-Cys4; and Cys starting from the amino terminal of the conantokin is respectively marked as Cys1, Cys2, Cys3 and Cys4 in sequence. Experiments prove that: Bt1.3 linear peptide (RKCCSNPACNRYNPAIC) is synthesized by an Fmoc-solid-phase peptide synthesis method, and is folded by one step in buffer solution of NH4HCO3 to form the Bi1.3 conantokin; and analgesic experiments prove that the alpha conantokin has high analgesic activity in rat sciatic nerve hemisection models.

The invention belongs to the technical field of medicine, and designs and synthesizes a series of disulfide bond-containing micromolecular prodrugs in which carbon chains in different lengths are linked (sulfur atoms in the disulfide bond are respectively located alpha, beta and gamma sites of an ester bond). PTX (Paclitaxel)-CIT (Citronellol) is used as a sample, and a synthesis method is simpleand easy. On the basis, a micromolecular prodrug self-assembly nano-drug delivery system is prepared. The preparation method is simple and convenient, the stability is high, and efficient encapsulation and delivery of drugs are realized. The invention discovers that the disulfide bond has redox dual sensitivity, can be fractured under the action of high-expression ROS (Reactive Oxygen Species) andGSH (Glutathione) of tumor cells, and PTX can be released; particularly, redox dual hypersensitivity is shown by PTX-CIT prodrugs (alpha-PTX-SS-CIT), which are located in the alpha site of a carbonylgroup, of the disulfide bond, the alpha-PTX-SS-CIT prodrugs can be quickly fractured to release the PTX and take effects, an anti-tumor effect of the PTX is remarkably improved, and a wide development prospect is obtained.

The invention provides a nanogel with hydrophilic and hydrophobic reversal, charge reversal and intracellular redox responsiveness on the basis of pH regulation. The nanogel is prepared by cross-linking of thermo-sensitive monomer with controllable radical polymerization, amphoteric ionic monomer and amido-containing pH sensitive monomer through a disulfide-bond-containing cross-linking agent. The invention further provides a nanogel drug carrier system with smart response to tumor microenvironment and its preparation method. On the condition of blood pH 7.4, the nanogel is in a hydrophilic swelling state that is favorable for avoiding being phagocytosed by the reticuloendothelial system (RES) and accordingly, the nanogel has blood long circulation capacity; on the condition of tumor tissue subacidity, the state of the nanogel is reversed into a hydrophobic shrinking state that is favorable for the nanogel to realize effective concentration, depth penetration and be absorbed effectively by tumor cells on the tumor location. Besides, in the intracellular lysosome environment, negative charge of the nanogel is reversed into positive charge, which is favorable for the nanogel to escape from the lysosome; and then the nanogel releases drugs responsively in cytoplasm high-GSH environment, thereby achieving a good tumor inhibition effect.

The invention provides a reduction-sensitive-type water-soluble molecularly-targeted photosensitizer. The photosensitizer is a conjugate which is formed by sequentially connecting meso-tetrahydroxy phenyl chlorine (mTHPC) with a folic acid group through a carbonic ester bond, a disulfide bond and a PEG chain. The invention further provides a chlorine intermediate and a folic acid PEG cysteine amide intermediate which are used for preparing the photosensitizer and a preparation method of the targeted photosensitizer. According to the photosensitizer which has the good tumor targeting performance, the photodynamic activity and water solubility, by introducing the disulfide bond and the carbonic ester bond into the molecular structure, the targeted photosensitizer can generate an exchange reaction of a sulfydryl and the disulfide bond and a nucleophilic substitution reaction in molecules in a strong reducing environment of a tumor cell after entering the cell, therefore, the mTHPC is completely released, and it is guaranteed that the photodynamic activity of the mTHPC cannot be reduced due to the structural change.

The invention discloses a cyclic chimeric citrullinated peptide antigen and an application thereof. The preparation of the cyclic chimeric citrullinated peptide antigen comprises the following steps: firstly connecting and jogging three small-molecular antigen peptides, namely a citrullinated peptide1, a citrullinated peptide 2 and a citrullinated peptide 3 derived from a silk polymerizing protein/an intermediate filament protein, and then synthetizing a cyclic polypeptide with a similar protein beta-corner structure by forming a disulfide bond through two cysteines inserted into the end N and the end C of a chimeric peptide. The cyclic chimeric citrullinated peptide antigen coats a solid-phase vector to prepare an indirect enzyme linked immunosorbent assay kit used for detecting the hypotype of multiple anti-citrullinated protein antibodies contained in RA (Rheumatoid Arthritis) serum. The cyclic chimeric citrullinated peptide antigen and the ELISA kit thereof which are disclosed by the invention have the advantages of simple preparation and experimental operation process, good result repeatability, qualification or quantification and wide clinical application and scientific research value and are outstandingly enhanced in detection sensibility and diagnosis value on RA compared with an international similar kit.

The invention relates to a preparation method of meso-porous silicon nanoparticle with reducing/enzyme dual response and targeting property. The preparation method of the meso-porous silicon nanoparticle with the reducing/enzyme dual response and targeting property comprises the following steps: synthesizing a meso-porous silicon nanoparticle; modifying a disulfide bond on the surface of the meso-porous silicon nanoparticle by adopting a chemical method, and grafting the disulfide bond with hyaluronic acid as a targeting molecule; by taking carboxyl on the targeting molecule as a reaction site, modifying polyethylene glycol to the surface of the compound nanoparticle, thus improving biocompatibity of the nanoparticle, and connecting the hyaluronic acid molecule with the targeting effect to the surface of the nano particle, thus obtaining the meso-porous silicon nanoparticle diagnosis agent with medicinal response releasing and imaging functions. The prepared particle has good dispersity, is uniform in particle size and is easy to prepare, the prepared multifunctional diagnosis agent has good biocompatibility, medicine can be released in a tumour part in a responding manner, and diagnosis integration of the tumour can be realized.