608 results about "Specific enzyme" patented technology

A method is provided of localizing a drug action where the drug is present throughout a vascular system. The localization occurs to within a volume of blood in a blood vessel, the vascular system having an initial temperature substantially within a first temperature range. A temperature-specific enzyme is delivered throughout a vascular system including a volume of blood in a blood vessel, the temperature-specific enzyme having a working temperature within a prespecified temperature range that does not substantially overlap the first temperature range. A heat transfer element is delivered to a blood vessel in fluid communication with the volume of blood. The temperature of the heat transfer element is adjusted such that the volume of blood in the blood vessel is heated or cooled to the prespecified temperature range. In this way, the action of the temperature-specific enzyme is substantially limited to the volume of blood heated or cooled. In an alternative embodiment, the temperature-specific enzyme is localized to the volume of blood in the blood vessel, and the heat transfer element is disposed in fluid communication with the volume of blood in the blood vessel. The enzyme localization may occur by way of direct injection or by way of injection through a lumen of a catheter. The injection lumen of the catheter may be disposed at least partially adjacent or in combination with the heat transfer element and its associated inlet and outlet lumens.

A lateral flow chromatographic assay format for the performance of rapid enzyme-driven assays is described. A combination of components necessary to elicit a specific enzyme reaction, which are either absent from the intended sample or insufficiently present therein to permit completion of the desired reaction, are predeposited as substrate in dry form together with ingredients necessary to produce a desired color upon occurrence of the desired reaction. The strip is equipped with a sample pad placed ahead of the substrate deposit in the flowstream, to which liquid sample is applied. The sample flows from the sample pad into the substrate zone where it immediately reconstitutes the dried ingredients while also intimately mixing with them and reacting with them at the fluid front. The fluid front moves rapidly into the final "read zone" wherein the color developed is read against predetermined color standards for the desired reaction. Pretreatment pads for the sample, as needed, (e.g. a lysing pad for lysing red blood cells in whole blood) are placed in front of the sample pad in the flow path as appropriate. The assay in the format of the invention is faster and easier to perform than analogous wet chemistry assays. A specific assay for glucose-phosphate dehydrogenase ("G-6PD") in this format is disclosed.

The present invention provides methods, compositions, and kits comprising snap-back primers used for forming 3′ hairpin structures, 5′ hairpin structures, and double hairpin structures. The hairpin structures may be used for detecting target sequences (e.g., such as small RNA target sequence), for detecting polymorphisms in target sequences (e.g., such as polymorphisms located near the 5′ or 3′ ends of the target sequence), or other nucleic acid characterization methods. In certain embodiments, the hairpin structures form invasive cleavage structures (e.g., in combination with a probe or upstream oligonucleotide) which may be cleaved by structure-specific enzymes in order to detect the presence or absence of a particular nucleotide or nucleotide sequence.

The invention discloses recombinant bacillus subtilis capable of increasing the yield of N-acetylneuraminic acid, and belongs to the field of genetic engineering. Supply of phosphoenolpyruvic acid in the synthesis pathway of N-acetylneuraminic acid is increased by taking bacillus subtilis (bacillus subtilis 168 delta nagP delta nagP delta gamP delta gamA delta nagA delta nagB delta 1dh delta pta::lox72; delta ctc::p43-Gna1, pP43NMK-AGE-NeuB) as an expression host and knocking out ptsG of a glucose specific enzyme EIICBA component of a phosphotransferase system, and therefore the synthesis passway is enhanced; compared with an original strain, the recombinant bacillus subtilis has the advantages that the yield of N-acetylneuraminic acid is increased to 660 mg/L from 190 mg/L, and a foundation is laid for improving N-acetylneuraminic acid production from bacillus subtilis in metabolic engineering.

Provision of a method for accurate diagnosis of mucopolysaccharidoses, including determining the level of glycosaminoglycan in a biological sample with high sensitivity and with ease. A diagnostic method of mucopolysaccharidoses including the following steps (1) and (2): (1) a step including (a) filtering a biological sample with an ultrafiltration filter, digesting the sample on the filter with a glycosaminoglycan-specific enzyme, centrifuging the digested sample to obtain a filtrate, or (b) digesting a biological sample with a glycosaminoglycan-specific enzym, filtering the sample with an ultrafiltration filter to obtain a filtrate, applying the filtrate obtained by (a) or (b) to a liquid chromatograph/mass spectrometer, and analyzing glycosaminoglycan-derived disaccharides, and (2) a step of diagnosing a subject as having mucopolysaccharidosis, chemically diagnosing effect of treatment of mucopolysaccharidoses, or determining types of mucopolysaccharidoses, on the basis of quantitative concentration data and disaccharide composition obtained in step (1).

The invention provides Bacillus sp Alg07 capable of producing an alginate lyase. The preservation number of the Bacillus sp Alg07 is CGMCC No.9391. The Bacillus sp Alg07 provided by the invention has the advantages that requirement on nutrition is low and fermentation time is short; a crude enzyme is easily prepared, and the crude enzyme can be obtained through centrifugation; the alginate lyase produced by the Bacillus sp Alg07 has high enzyme activity, the specific enzyme activity of an unpurified crude enzyme can reach 20000-40000 U/mg (563U/mL); the alginate lyase produced by the Bacillus sp Alg07 has good stability, is not obviously changed in enzyme activity after being preserved at 40 DEG C for 24 hours and is high and stable in enzyme activity at pH of 5.5-8.5; and the produced alginate lyase is capable of degrading sodium alginate to generate alginate-derived oligosaccharide with biological activity.

A lateral flow chromatographic assay format for the performance of rapid enzyme-driven assays is described. A combination of components necessary to elicit a specific enzyme reaction, which are either absent from the intended sample or insufficiently present therein to permit completion of the desired reaction, are predeposited as substrate in dry form together with ingredients necessary to produce a desired color upon occurrence of the desired reaction. The strip is equipped with a sample pad placed ahead of the substrate deposit in the flowstream, to which liquid sample is applied. The sample flows from the sample pad into the substrate zone where it immediately reconstitutes the dried ingredients while also intimately mixing with them and reacting with them at the fluid front. The fluid front moves rapidly into the final "read zone" wherein the color developed is read against predetermined color standards for the desired reaction. Pretreatment pads for the sample, as needed, (e.g. a lysing pad for lysing red blood cells in whole blood) are placed in front of the sample pad in the flow path as appropriate. The assay in the format of the invention is faster and easier to perform than analogous wet chemistry assays. Specific assays for glucose-6-phosphate dehydrogenase ("G-6PD"), total serum cholesterol, beta-lactamase activity and peroxidase activity are disclosed.

The invention discloses a method for detecting the specific antibody of classical swine fever virus and a special ELISA kit thereof. The kit includes a classical swine fever virus antigen and an enzyme-labeled classical swine fever virus single-epitope specific antibody; the said swine fever virus antigen is a polypeptide containing one or more than one amino acid residue sequence described in sequence 1. The detection reagent of the classical swine fever virus specific antibody of the present invention can carry out effective detection to the classical swine fever virus specific antibody by solid-phase antigen competition ELISA (blocking method); The B cell epitope ensures the differential diagnosis, and the high degree of conservation of the epitope among various strains ensures the specificity of detection.

The invention discloses an alginate lyase (Alg509) derived from marine bacteria and a gene thereof, and also disclosed a method for recombinant expression and preparation of the alginate lyase. According to the method, the alg509 gene is cloned into an E. coli expression vector, and the vector is transformed into an E. coli host strain to obtain a recombinant engineering strain which can heterologously express the enzyme. The alginate lyase Alg509 disclosed in the invention has high enzyme activity, the specific enzyme activity can reach up to 48000 U/mg and above, the optimum reaction pH is 10, the optimum reaction temperature is 55 DEG C, and the enzyme activity has no dependence on various metal ions. The enzyme is active to sodium alginate, poly-guluronic acid (polyG) and ploymannuronic acid (polyM), and can completely degrade sodium alginate to produce alginate oligomers such as alginate disaccharide, alginate trisaccharide, alginate tetrasccharide, etc. The enzyme exhibits strongbasophilia, has certain tolerance to high pH, has certain potential of industrial applications, and can be widely applied in the fields of agriculture, food, feed additive, medicine and the like.

The invention discloses a chromogenic medium of a coliform group and a quick detection card thereof. The medium contains peptone, yeast extract, lactose, common salt, sodium pyruvate, SDS, sodium dihydrogen phosphate, a specific enzyme chromogenic substrate and IPTG. The quick detection card consists of, in a bottom-up order: a negative film, a water absorption and moisture retention layer, a medium layer and a covering membrane, with the above medium adsorbed on the medium layer. The chromogenic medium of a coliform group and the detection card that are provided in the invention can detect coliform groups in drinking water, surface water or foodstuff, with short detection time and high efficiency. The chromogenic medium and the detection card of the invention can conduct qualitative detection to coliform groups, and simultaneously can carry out quantitative analysis. And a positive result has obvious color development and is convenient for observation, odds for emergence of false positive and false negative can be reduced, and the detection result is accurate.

The invention relates to a ketone reductase mutant and a preparation method thereof. The ketone reductase mutant comes from a saccharomyces cerevisiae wild type ketone reductase, is capable of converting 5-hydroxyl-3-oxohexanoate into corresponding cis 3,5-dihydroxylhexanoate, and has one or more mutants of I46V, S127N and Q144K. The ketone reductase mutant has obvious high specific enzyme activity which is improved by 2-100 times compared with that of the wild type ketone reductase, can be utilized to biologically catalyze 5-hydroxyl-3-oxohexanoate to product corresponding cis 3,5-dihydroxylhexanoate. The reaction conditions are mild, requirements on equipment are low, the production process does not need high temperature or cooling, and energy consumption is low. Because enzyme catalysis has efficient specific selectivity, the process of producing the statin medicine key intermediate cis 3,5-dihydroxylhexanoate, does not generate by-products, and purification is convenient. Additionally, the solvent employed in the reaction is mainly water, "three wastes (waste gas, waste water and industrial residue)" discharge is low, and the reaction is green and environment-friendly.

The invention discloses a microbe combination of degraded stalks and its preparing method as well as a method of degrading the stalks, where the microbe combination includes: liquid bacterial strain, and solid bacterial strain, the liquid bacterial strain is made by culturing plant lactobacillus, Streptococcus faecali, and Candida utilis in the culture medium and the solid bacterial strain is made by culturing Phanerochaete chrysosporium and Pleurotus ostreatus; the method of degrading the stalks by the combination: mixing the liquid bacterial strain with the stalks raw material in weight ratio of 1 to 15000-25000, adding in 0.9% NaCl water solution to make the water ratio reach 65-70%, sealing and fermenting in a sealed container as 25-30deg.C for 7-10 days and take out; adding in the solid bacterial strain and mix uniformly, fermenting at 25-30 deg.C, and when the mycelium grows completely and drying into the finished products. It simulates the ecological mode of biodegrading stalks in the nature, fully uses specific enzyme system of each bacterial strain, and achieves the purpose of biodegrading stalks.

The invention discloses an L-asparaginase mutant with the improved enzyme activity and a construction method thereof, and belongs to the field of gene engineering. According to the L-asparaginase mutant, on the basis of amino acid shown in the SEQ ID NO.2, the 107th glycine is mutated into aspartic acid. The obtained mutant is expressed in bacillus subtilis, fermentation is performed in a shake flask for 24 h and then the enzyme activity is 961 U/mL; the enzyme activity of the mutant is improved by 80%, the appetency of a substrate is decreased by 50% compared with protoenzyme, the catalytic efficiency is improved by 84%, and meanwhile the specific enzyme activity is improved by 83%. According to the L-asparaginase mutant, it is shown that the 107th amino acid residue has a great influence on the enzyme catalytic action, a certain foundation is provided for research on the enzyme catalytic mechanism, and the enzyme industrial application potential is improved.

The invention relates to truncated recombinant alginate lyase rAly1-T185N, and an encoding gene and application thereof. The amino acid sequence of the truncated recombinant alginate lyase rT185N is as shown in SEQ ID NO.2; the nucleotide sequence of the encoding gene of the truncated recombinant alginate lyase rT185N is as shown in SEQ ID NO.1. 185 amino acid residues are cut off from the N end of the full-length alginate lyase rAly-1 to obtain T185N truncated enzyme; the expression quantity of the rT185N can reach 1259+/-2.2 mg/L fermentation liquid, the specific enzyme activity can reach 2895+/-10.3 U/mg, the expression quantity is increased by about 2.6 times compared with that of full-length protein rAly-1, the aims of increasing yield, saving energy and improving economic benefit are fulfilled, and rT185N can realize one-step purification of fusion protein through nickel column separation.

The invention provides a polypeptide-DNA hydrogel and a preparation method, wherein, the polypeptide-DNA hydrogel comprises the following components: polypeptide, wherein a single chain DNA molecule enables covalent binding on the polypeptide; a double chain DNA molecule, wherein the double chain DNA molecule has two cohesive ends; wherein the cohesive ends and the single chain DNA molecule are complementary, and polypeptide forms a crosslinking structure through the complementation of the cohesive ends of the double chain DNA molecule and the single chain DNA molecule. The mechanical strength of the polypeptide-DNA hydrogel can be adjusted, the biocompatibility is good, and the polypeptide-DNA hydrogel has reversible thermal responsiveness and specific enzyme responsiveness.