9 results about "Cholesterol oxidase" patented technology

The application discloses a marine-derived cholesterol oxidase and a preparation method and application thereof, and relates to the technical field of biology. The amino acid sequence of the marine-derived cholesterol oxidase (SkChOx) is shown in SEQ ID NO. 1 or 3, the specific enzyme activity of the marine-derived cholesterol oxidase can reach 31.9 U / mg, the marine-derived cholesterol oxidase has excellent anti-reverse performance, maintains high stability in the pH range of 5.0-10.0, has good temperature tolerance, organic solvent tolerance and metal ion tolerance, and exhibits unique salt activation effect and salt tolerance. The enzyme is compounded with dithiothreitol (DTT) and nonylphenol polyoxyethylene ether (NP-40) to form a liquid enzyme preparation, and after incubation at 37 DEG C for 7 days under accelerated conditions, the catalytic activity of the liquid enzyme preparation still remains about 87%, the liquid enzyme preparation has excellent long-acting storage stability, and has wide application prospects in the fields of clinical diagnosis, food physical and chemical inspection, biosensor development and industrial preparation of steroid drugs.

A method of treating a cancer (e.g., a colorectal cancer, a liver cancer, a breast cancer, or a lung cancer) in a subject in need thereof by administering to the subject a therapeutically effective amount of (i) a bacterium that converts intestinal cholesterol to 4-cholesten-3-one (4-C-3) or (ii) 4-C-3. Also disclosed is a recombinant Escherichia coli TOP10 bacterium comprising a nucleic acid encoding cholesterol oxidase (CHOX), which is capable of converting cholesterol to 4-C-3 and can be used to treat gastrointestinal tract cancers including a colorectal cancer or lung cancer.

The invention relates to the technical field of nano-drugs, in particular to a nano-drug for treating triple negative breast cancer as well as a preparation method and application of the nano-drug. The nano-drug takes hyaluronic acid modified hollow mesoporous copper zinc sulfide nanoparticles as a carrier, and cholesterol oxidase is loaded in the nano-drug. The preparation method adopts a one-pot wet chemical method, and a carrier with a regular structure is formed based on a Kirkendall effect. The nano-drug disclosed by the invention can be delivered to a tumor site in a targeted manner, is rapidly degraded in a weak acid microenvironment, synchronously releases cholesterol oxidase, metal ions with Fenton-like activity and H2S gas, and synergistically sensibilizes ferroptosis and efficiently eradicates tumor stem cells by triggering a cascade reaction of cholesterol depletion-lipid raft destruction-lipid peroxidation storm; a brand new treatment scheme is provided for solving the problems of drug resistance and relapse of the triple negative breast cancer.

The present application constructs a fusion protein by utilizing the specific affinity adsorption property of a carbohydrate binding module (CBM) to cellulose, the fusion protein comprising a cholesteric oxidase and a carbohydrate binding module (CBM), and then uses nanocellulose membranes as the immobilization carrier of the fusion protein for preparing a biosensor element, and the obtained biosensor element can exhibit good catalytic properties and detection stability.

The invention discloses a medical composite material for synergistically regulating cholesterol and oxidative stress. The material comprises a Fe2-N6 / NC carrier, cholesterol oxidase loaded on the Fe2-N6 / NC carrier and a hyaluronic acid targeting layer modified on the surface, the carrier is a nitrogen-doped carbon material loaded with iron double-atom active sites, the distance between adjacent iron atoms is 0.311 + / -0.009 nm, and the iron content is 0.393 wt%; the average particle size of the composite material is 242.5 nm, and the Zeta potential of the composite material is-23.71 mV; the preparation method comprises the following steps: synthesizing Fe2-N6 / NC through mechanochemical-assisted in-situ MOF packaging, ultrasonically loading cholesterol oxidase and modifying with hyaluronic acid. The material has cholesterol degradation activity (the degradation rate is 33.94%) and active oxygen scavenging activity (the scavenging rate is 78.8%), and can be used for preparing an implant material for joint repair or a medical material for articular cavity injection so as to realize coordinated regulation of osteoarthritis cholesterol metabolism disorder and oxidative stress.

The invention provides a method for synthesizing 4-cholestene-3-ketone based on microorganisms of a cholesterol oxidase truncation. The invention specifically provides a method for producing 4-cholestene-3-ketone, which comprises the following steps: culturing a host cell to obtain a culture product; wherein the host cell can synthesize cholesterol and heterologously express cholesterol oxidase; the cholesterol oxidase truncation is selected from cholesterol oxidase without a complete signal peptide function; and extracting and separating the target product 4-cholestene-3-ketone from the culture product of the host cell. According to the invention, the conversion from cholesterol to 4-cholestene-3-ketone can be directly completed in a living cell environment.

This invention discloses a dry chemical reagent for total cholesterol detection, comprising a diffusion layer, a spacer layer, and a reagent layer sequentially overlapped. The diffusion layer includes reflective particles, a binder, a surfactant, cholesterol esterase, and cholesterol oxidase. The reagent layer includes a carrier, horseradish peroxidase, an indicator composition, and a buffer solution. The dry chemical detection reagent of this invention employs a coating method, layering a premixed homogeneous slurry onto a support layer. A spacer layer blocks interlayer interference, and phenolic substances replace photosensitizers as chromogens, combined with a specific ratio of substrate and buffer system. The multi-layered, spacer-free, low-interference vertical detection system constructed by this invention significantly improves the repeatability, accuracy, and stability of the detection reagent.

The invention discloses a cholesterol oxidase mutant as well as an expression strain and application thereof. According to the invention, cholesterol oxidase from uncultured microorganisms is used as a starting enzyme, a mutation site is obtained through multiple designs of Evcouplings and FoldX, then a recombinant plasmid is constructed, and a mutant gene is obtained. After induced expression of the engineering bacteria containing the mutant plasmids, cholesterol oxidase with improved stability and specific enzyme activity is obtained. Under the condition of 37 DEG C, the specific enzyme activity of the mutant is improved to 4.26 times, and the stability is improved to 1.15 times. The mutant has application value in an enzyme-method cholesterol in-vitro detection diagnostic kit.

The electrochemical cholesterol biosensor comprises a flexible substrate and a three-electrode system formed on the flexible substrate, and the three-electrode system comprises a working electrode, a counter electrode and a reference electrode which are respectively provided with a detection end and an electric connection end; the working electrode is constructed as follows: a detection end of the working electrode comprises an electrode base layer as well as artificial nano-enzyme and cholesterol oxidase which are modified on the surface of the electrode base layer; the artificial nano-enzyme is of a binary alloy hollow cage structure which has catalase activity and is composed of first precious metal and second precious metal. The invention further discloses a preparation method and application of the electrochemical cholesterol biosensor. According to the invention, non-invasive, real-time and continuous monitoring of the cholesterol concentration of sweat can be realized.