37 results about "S-Adenosylhomocysteine" patented technology

The invention relates to an enzymology measuring method and reagent with circular increment technology, applied to measure the content of homeotypic cysteine in the measured sample. The character is: with a circular increment technology, increases the measurement sensitivity, thus it can carries on automatic measurement to the homeotypic cysteine in the sample liquid like normal enzymology diagnosing agent. The homeotypic cysteine in the sample liquid reacts with the S-adenosine-L-methionine repeatedly and circularly under the effect of homeotypic cysteine methyl kinase and adenosine homeotypic cysteine, generates the adenosine, the speed of the adenosine generation is in direct proportion to the homeotypic cysteine in the sample, through the generation speed, the aim to measure the content of the homeotypic cysteine in sample can be achieved.

This invention pertains to a method for detecting a compound in the presence of other compounds that are substantially similar in structure and metabolically related to the analyte. The invention is particularly suited for the detection of S-adenosylmethionine in the presence of S-adenosylhomocysteine, other nucleosides and derivatives in a biological sample. The methods of this invention involve an antibody produced specifically against S-adenosylmethionine; particularly, analogs modified strategically at the sulfonium position. An assay protocol comprises chemically modified analyte analog linked to an enzymatic reporter and the aforementioned antibody was used to demonstrate the assay specificity and sensitivity. Additional assay method with immobilized immunogen, the specific antibody, and an enzyme labeled secondary antibody was also described for illustration. The invention also features hapten design and novel compounds used as haptens to prepare immunogen and for the specific antibody production.

The invention provides immunochromatographic test strips and methods for detecting and quantifying S-Adenosylmethionine (SAM), S-Adenosylhomocysteine (SAH) and Homocysteine (HCy) in a sample, comprising: (a) making fluorophore conjugated antibodies; (b) immobilizing SAM, SAH and HCy on a solid support; (c) providing a sample, combining said sample with a conjugate selected from the group consisting of lanthanide chelate conjugates and quantum dot conjugates (QD) with anti-SAM, anti-SAH or anti-HCy, wherein said combining is performed under conditions that allow formation of a competitive complex comprising said conjugate, said SAM, SAH or HCy on the solid support and SAM, SAH or HCy in a sample when present; and (d) detecting the presence of the complex, if present, by monitoring a spectral emission mediated by the fluorescent conjugates in the complex, wherein the emission indicates the presence and quantity of SAM, SAH or HCy in the sample.

Provided are methods of designing a putative inhibitor of a 5′-methylthioadenosine/S-adenosylhomocysteine nucleosidase. The methods comprise designing a chemically stable compound that resembles the charge and geometry of the 5′-methylthioadenosine/S-adenosylhomocysteine nucleosidase transition state. Also provided are methods of inhibiting 5′-methylthioadenosine/S-adenosylhomocysteine nucleosidases using the inhibitors found by the above methods.

The invention provides a monoclonal antibody 301 specifically binding S-adenosyl-L-homocysteine or an antigen-binding site of the monoclonal antibody, a hybridomas generating the monoclonal antibody, a composition or a kit comprising the monoclonal antibody 301 or the antigen-binding site, and test paper comprising the monoclonal antibody 301 or the antigen-binding site of the monoclonal antibody. The invention also provides a method of achieving non-treatment or diagnosis objectives of detecting existence of the S-adenosyl-L-homocysteine or the level of the S-adenosyl-L-homocysteine in a sample by using the monoclonal antibody 301 or the antigen-binding site, the composition or the kit, and provides uses of the method. A cell strain and a product thereof allow an immune method to be capable of detecting the methylation index (namely a ratio of S-ademetionine to the S-adenosyl-L-homocysteine) in a metabolic activity process of life for the first time. The obtained anti-S-adenosyl-L-homocysteine monoclonal antibody cell strain will have high practicability and a good application prospect.

The invention discloses a diabetic nephropathy diagnostic kit and the application thereof, and particularly discloses the application of inosine serving as a biomarker in preparation of a diagnostic kit for diabetes and the diabetic nephropathy, and the application of the combination of the inosine, adenosine and S-adenosyl homocysteine and the combination of the adenosine, the S-adenosyl homocysteine and linoleic acid serving as markers in preparation of the diabetic nephropathy diagnostic kit. The invention also discloses the diagnostic kit prepared by the biomarkers, which can be used for distinguishing the diabetic nephropathy and staging different development stages of the diabetic nephropathy, performing screening and assessment analysis on the treatment medicaments for different development stages of the diseases, and provides accurate basis for the treatment and the diagnosis of the diabetes and the diabetic nephropathy.

The invention discloses a method for measuring the activity of transmethylase in real time and a kit. The method comprises two reactions carried out at the same time in a reaction system; according to the first reaction, in a buffer system where it is guaranteed that S-ademetionine is adopted as a methyl donor and the transmethylase has the biological activity, a sample containing the transmethylase (MT), the methyl donor and a corresponding substrate are added, or the S-ademetionine methyl donor and the corresponding substrate are directly added into the liquid sample containing the transmethylase, and a reaction is carried out so that an S-adellosyl homocysteine (SAH) product can be generated, wherein the substrate is receptor matter of methyl; according to the second reaction, an immunological method is adopted for detecting the content of SAH to determine the activity of the transmethylase in the reaction system. The biochemical reaction of MT catalysis and the immunoreactions for measuring the product SAH are carried out at the same time, the two processes are organically combined, and great significance is especially achieved on accurate measurement of SAH with extremely unstable molecularity.

The present invention relates to a method of producing homocysteine diagnostic kit, which is based on the small molecule capture technology. The method adopts the combination of gene mutation enzyme and small molecule substance to be detected; the gene mutation enzyme is named as small molecule capture enzyme; and the small molecule capture enzyme after mutation and modification maintain and even enhance the affinity to the substrate or the small molecule substance to be detected, but the catalytic capability and the decomposition capacity of the small molecule capture enzyme after mutation and modification to the substrate or the small molecule substance to be detected is weakened. The invention provides a method of researching and producing the homocysteine (HCY) diagnostic kit, which is based on the small molecule capture technology, and also provides mutated S-adenosine homocysteine hydrolase; and the specific S-adenosine homocysteine (SAH) capture enzyme can fully maintain and even enhance the affinity to the S-adenosine homocysteine (SAH), but the catalytic capability to the HCY or the S-adenosyl homocysteine (SAH) is weakened. The method is in particular suitable for small molecule substances, such as inorganic ions, amino acids, polypeptides, nucleotides, oligonucleotide, vitamins, monosaccharides, oligosaccharides, lipids and organic acids.

The present invention relates to compositions and methods for assaying homocysteine (Hcy) and thus related moieties, e.g., S-adenosylhomocysteine (SAH) or adenosine. More particularly, assay methods that employ, mutant SAH hydrolase having binding affinity for Hcy, SAH or adenosine but has attenuated catalytic activity, are provided. The modified enzymes and fusion proteins containing the modified enzymes are also provided.

A medical application of S-adenosine homocysteine in preparing immunodepressant with high effect and low poison is disclosed.

The invention discloses a competition-method-based homocysteine fluorescent immunochromatography detection kit and a using method thereof. The kit comprises a reagent I, reagent II and a fluorescent immunochromatographic strip. The reagent I contains dithiothreitol (DTT), adenosylmethionine, homocysteine methyltransferase, a buffer solution, and a stabilizer. The reagent II contains a biotinylatedpolystyrene fluorescent microsphere, a buffer solution, and a stabilizer. The test strip includes a sample pad, a binding pad coated with a biotinylated antibody, an NC membrane containing a detection line and a quality control line, a piece of absorbent paper and a PVC rubber sheet. The competitive fluorescent immunochromatography is used for detecting the adenosine homocysteine, thereby detecting the homocysteine. The method is operated simply and is capable of detecting lots of samples; the interference factors are reduced; and the cost is low.

The invention discloses a method for detecting homocysteine concentration, and the method is characterized in that to-be-detected substrate homocysteine is catalyzed by gene engineering fusion enzymes to obtain product adenosine, the adenosine production rate is in direct proportion to homocysteine content in a sample, and the homocysteine content in the sample can be detected by detecting the adenosine. The used gene engineering fusion enzymes are a fusion enzyme of homocysteine methyltransferase (EC2.1.1.10) and adenosine homocysteine enzyme (EC3.3.1.1), and a fusion enzyme of the adenosine homocysteine enzyme (EC3.3.1.1) and methionine adenosyltransferase (EC2.5.1.6). According to the method, an efficient fusion enzyme protein can be established for detecting the homocysteine, by use of efficient catalytic activity of the fusion enzymes, the sensitivity of ordinary enzymatic reaction and the stability of a detection reagent can be greatly improved, and a new methodological improvement area is proposed for an enzyme cycle detection method.

This invention provides methods to determine the activity of methyltransferase enzymes which employ S-adenosylmethionine (SAM) as a substrate and transfer a methyl group to convert this substrate to S-adenosylhomocysteine (SAH), by measuring SAH conversion to AMP.

The invention provides bioconjugates of heterocylic compounds such as S-adenosylmethionine and S-adenosylhomocysteine with biotin or digoxigenin. The bioconjugates also include carbon and nitrogen linker moieties of varying length that are used to attach such compounds to biotin or digoxigenin. The conjugates are useful in immunoassays. The invention provides a method for detecting SAM and SAH, comprising the steps of: (a) preparing the following components: (i) bio-conjugates of SAM, SAM analogs or SAH; (ii) an europium, a terbium cryptate or other fluorophore as a donor that has a specific ligand for the tracer in the bio-conjugates of (i); (iii) an acceptor fluorescent dye that has the excitation spectra overlap those of donor's emissions and has an antibody specific for SAM or SAH labeled; (b) addition of the biological fluid containing said SAM or SAH; and (c) spectroscopic measurement of the fluorescence of the donor and the fluorescence of from the acceptor.

The invention relates to a homocysteine diagnosis/determination reagent (kit) using enzyme-colorimetry and enzyme-linked method technology. Meanwhile, the invention also relates to a homocysteine concentration determination method, reagent compositions and components, which belong to the technical filed of medical test and determination. The reagent (kit) of the invention mainly includes: buffer solution, coenzyme, glutathione disulfide, dihydrogen monacus anka L, sodium bicarbonate (carbon dioxide), S-adenosyl-homocysteine, glutathione homocysteine transhydrogenase, glutathione-coenzyme A-glutathione transhydrogenase, S-adenosyl homocysteine, glutathione homocysteine transhydrogenase, glutathione-coenzyme A-glutathione transhydrogenase, lovastatin nonaketide synthase and stabilizing agent; samples and reagent are mixed according to a certain volume ratio to generate a series of enzymatic reactions; then the reactants are arranged under an ultraviolet/visible light analyzer to detect the increasing degree of absorbance at the 340nm position of a dominant wave so as to measure and calculate the concentration of the homocysteine.

The present invention provides a preparation method of an SAM (S-Adenosyl-L-homocysteine) artificial complete antigen. The method comprises the following steps: SAM is mixed with di-tert-butyl dicarbonate to obtain a first Intermediate, wherein di-tert-butyl dicarbonate is used for protecting epitope in SAM; adding carrier protein to the first intermediate, and obtaining a second intermediate after the reaction; and removing di-tert-butyl dicarbonate in the second intermediate to obtain the SAM artificial complete antigen. The SAM artificial complete antigen prepared by the method has high specificity, selectivity and immunogenicity. The invention also provides the SAM artificial complete antigen prepared by the method and an application of the SAM artificial complete antigen to antibody preparation.