148 results about "Adenosine deaminase" patented technology

The present invention relates to the production of adenosine deaminase (ADA) deficient mice and the use of such mice as an animal model for dysfunctions associated with elevated adenosine levels. Also, provided by the present invention are methods of treating dysfunctions associated with elevated adenosine levels and methods of screening compounds for pharmaceutical activity in the treatment of dysfunctions associated with elevated adenosine levels.

The present invention relates to a method for quickly determining cAMP content or an adenylate cyclase activity in a biological sample containing non-cyclic adenine nucleotides without the use of radioactive agents.Particularly, the present invention provides a method of determining cAMP content or an adenylate cyclase activity in a biological sample containing non-cyclic adenine nucleotides selected from the group consisting of cAMP produced by endogenous adenylate cyclase, and AMP, ATP, ADP and a mixture thereof, which comprises (1) combining a biological sample with effective amounts of apyrase, adenosine deaminase and alkaline phosphatase to enzymatically remove non-cyclic adenine nucleotides other than cAMP, and glucose-6-phosphate in the sample; (2) enzymatically converting cAMP into AMP; (3) determining an amount of AMP without the use of radioactive agents, and a kit to carry out the method.

A reagent for detecting the activity of adenosine deaminase and its isozymes in body fluid specimen by enzyme method is prepared from the oxidation-type micotinamide coenzyme or its analog, and substrate to generate the slow-reaction enzyme-substrate-DNA (or NADP) system.

The invention relates to a site-directed RNA (Ribonucleic Acid) editing technology based on CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)-Cas13a, and discloses an RNA site-directed editing method based on the CRISPR-Cas13a. By use of the method disclosed by the invention, during RNA site-directed editing, under the guidance of a crRNA, a Cas13a mutant takes a catalytic structural domain of ADAR2 (Adenosine Deaminase Acting on RNA 2) to an appointed RNA position to finish the site-directed editing from A to I. The Cas13a mutant does not have ssRNA cleavage activity, has ssRNA binding activity and is blended with the catalytic structural domain of the ADAR2. On the basis, the design of the crRNA is also optimized.

The invention relates to electrochemiluminescence DNA logic gate constructed by adopting adenosine monophosphate and adenosine deaminase as excimers based on a specific binding effect of a aptamer and a ligand thereof, and a deamination effect of adenosine deaminase, wherein adenosine monophosphate aptamer-containing single-stranded DNA and two single-stranded DNA modified with a luminescence agent and a quenching agent are subjected to hybridization to form the DNA logic gate. According to the present invention, after adenosine monophosphate and the aptamer thereof are subjected to specific binding, the luminescence agent-modified single-stranded DNA is released, and is captured by the carbon nanotube-modified electrode so as to enhance the electrochemiluminescence signal; adenosine deaminase is added to catalyze deamination of adenosine monophosphate so as to destruct the binding effect of the adenosine monophosphate and the aptamer, and the aptamer and the luminescence agent-modified single-stranded DNA form the hybrid so as to separate from the electrode and reduce the electrochemiluminescence signal; and through the improvement of the logic gate structure and the introduction of the quenching agent, the background interference is reduced, and the detection sensitivity is improved.

The invention provides for systems, methods, and compositions for targeting and editing nucleic acids. In particular, the invention provides non-naturally occurring or engineered DNA-targeting systems comprising a DNA-targeting Cpf1 protein, at least one guide molecule, and at least one adenosine deaminase protein or catalytic domain thereof.

The invention discloses a xanthine dehydrogenase intercepting body and an application thereof. The protein comprises xanthine dehydrogenase intercepting body small subunit, xanthine dehydrogenase intercepting body intermediate subunit, and xanthine dehydrogenase intercepting body large subunit. The affinity of xanthine dehydrogenase intercepting body is increased by 19% by comparing a wild substrate (xanthine), the conversion number is increased by 115%, the catalysis efficiency is increased by 166%, and the temperature toleration is increased by 11 DEG C. The xanthine dehydrogenase intercepting body is in favor of developing the novel application field by combining with other enzymes, and is suitable for sample detection for detecting xanthine and hypoxanthine, the xanthine dehydrogenase intercepting body can be used for detecting inorganic phosphoric acid by combining with PNP enzyme, can be used for detecting adenosine deaminase by combining with PNP, XOD and POD enzymes and detecting 5'-nucleotidase, and is suitable for industrial application. The xanthine dehydrogenase intercepting body is in favor of increasing enzyme catalysis efficiency and reducing cost, and is in favor of industrial application.

A method of making didanosine (ddI) including the steps of: (a) obtaining an enzyme expressing ddA deaminase activity; (b) immobilizing the enzyme onto an insoluble support; (c) contacting the enzyme with a dideoxyadenosine (ddA) solution of at least about 4% weight volume ddA in water for a time and under conditions to produce a ddI solution; and (d) isolating the ddI from the ddI solution. Optionally, the ddI mother liquor is reused in subsequent runs to improve yield.

The invention belongs to the technical field of cell culture mediums, and particularly relates to a stem cell culture medium and a preparation method thereof. The stem cell culture medium provided by the invention comprises a basic culture medium and an additive, wherein counted by final concentration, the additive is prepared from 1 to 3mg/mL human serum albumin, 8 to 13mug/mL transferrin, 0.12 to 0.15mug/mL glucagon, 2.5 to 3mug/mL activated carbon, 13 to 18ng/mL fibroblast growth factor, 7 to 11ng/mL epidermal growth factor, 3 to 6 muM linoleic acid, 5 to 9mug/mL quercetin, 20 to 25mug/mL platycodin, 2 to 5mg/mL laminine, 3 to 7mug/mL adenosine deaminase and 1.2 to 1.6muM myristic acid. By adopting the stem cell culture medium provided by the invention, stem cells can be amplified rapidly, and the culture time of the stem cells is shortened greatly.

The invention relates to the technical field of detection of serum adenosine deaminase and in particular relates to a serum adenosine deaminase detection reagent. R1 comprises buffer solution, 4-aminoantipyrine, PNP, XOD, POD, bilirubin oxidase, ascorbic acid oxidase, glycerin, polyethylene glycol 6000, ethylene glycol, mannitol, mycose, BSA, alkyl glycoside and preservatives; R2 comprises buffer solution, adenosine, 3-hydroxy-2,4,6-triiodobenzoic acid, glycerin, polyethylene glycol 6000, ethylene glycol, mannitol, mycose, BSA, alkyl glycoside and preservatives. With the adoption of the novel Trinder reaction chromogen substance 3-hydroxy-2,4,6-triiodobenzoic acid, multiple stabilizers are added, and the stability of the reagent is obviously improved; and due to the added bilirubin oxidase, ascorbic acid oxidase and novel nonionic surfactant alkyl glycoside (APG), interference of bilirubin and ascorbic acid is avoided, a turbid reaction system is prevented, and the substrate stability and the interference resistance of the reagent are enhanced.

The invention relates to the biological field, in particular to a serum-free medium for stem cells. A medium additive comprises 5-30 g/L of human serum albumin, 1-10 g/L of plant-derived recombinant human serum transferring, 0.1-8 g/L of alpha1 acid glycoprotein, 0.1-8 g/L of alpha2-HS-glycoprotein, 0.05-5 g/L of apolipoprotein AI, 0.05-5 g/L of apolipoprotein AII, 0.01-2 g/L of hemopexin, 0.05-5 g/L of adenosine deaminase, 0.03-3 g/L of serine protease inhibitors, 0.01-3 g/L of transthyretin and 0.01-3 g/L of human insulin. According to the serum-free medium for stem cells, pathogen pollution from animal origins is eliminated, the components are defined, and therefore reproducibility and controllability of the serum-free medium are better than those of a serum medium; the effect of in-vitro culture of stem cells is superior to the effect of the serum medium, the expansion speed of stem cells is increased, and culture time for stem cells is greatly shortened.

The invention provides a method for determining the stability of a diagnostic reagent of adenosine deaminase by improving a coupling enzymatic reaction, which comprises the steps of adding different stabilizing agents in the diagnostic reagent of the adenosine deaminase, wherein the stabilizing agents comprise 10 to 100 mmol/L of calcium ethylene diamine tetracetate, 10 to 100 mmol/L of ferric ethylene diamine tetracetate, 5 to 100 mmol/L of sodium molybdate, 5 to 100 mmol/L of ammonium molybdate, 5 to 100 mmol/L of sodium glutamate, 8 to 10g/L of bovine serum albumin, and 0.5 to 10.0 KU/L of superoxide dismutase. A coupling enzymatic reaction reagent for determining the adenosine deaminase has higher stability by adding any one of the stabilizing agents into the reagent and maintaining the stabilizing agents within the concentration range; the method, which can be widely applied to clinical in vitro diagnosis in vitro and reduces the waste of the reagents.

The invention relates to the technical field of adenosine deaminase detection, in particular to an adenosine deaminase detection reagent. A reagent R1 comprises a buffer solution, 4-aminoantipyrine, BSA, cane sugar, trehalose, peroxidase, ascorbic acid oxidase, bilirubin oxidase and preservatives; a reagent R2 comprises a buffer solution, adenosine, EHSPT, BSA, cane sugar and preservatives. The adenosine deaminase detection reagent has the advantages that the phosphate buffer solution is adopted, the stabilizer BSA, the cane sugar and the trehalose are added, and accordingly, stability of the reagent is improved greatly; determination performance is improved remarkably, and stability and anti-interference capability of the reagent are enhanced.

Heinz(1980) makes use of the adenosine ammonia-deleted enzyme to change adenosine into hypo-yellow and gains H2O2 through the reaction of the enzyme1 and enzyme2. With the effect of the catalase and aldehyde hydrogen-deleted enzyme, Heinz measures the velocity of increase of the degree of NADPH absorbing light at 334 nms to gain adenosine ammonia-deleted enzyme's activity. The method's weakness is high cost of the reagents. The invention introduces Trinder's reaction to combine aniline type hydrogen and 4- to from a coloured product with the effect of H2O2 gained by the reaction of enzyme3 in the situation of the catalase. By watching the quantity of this coloured product, people can determine the adenosine ammonia-deleted enzyme's activity. The invention simplifies the Heinz's reaction system and lowers the cost. The invention uses the aniline compound ADOS, ADPS, ALPS, TODB, TOOS and TOPS as hydrogen provider for Trinder's reaction and increases the reaction's agility. The invention also involves a reagent box used for implementing the method mentioned above.

The invention provides an ADAR1 over-expressed virus vector, a preparation method of the virus vector, and application of the ADAR1 over-expressed virus vector in aspects of protecting the intestinalstructure integrity, maintaining the intestinal steady-state, improving the activity of intestinal macrophages, inhibiting the level of inflammatory cytokines and preparing products for treating sepsis. The ADAR1 over-expressed virus vector disclosed by the invention provides novel potential therapeutic targets for treatment of sepsis.

The invention relates to an adenosine deaminase detection kit. A vessel is contained in the detection kit and filled with liquid for detection, the liquid for detection is prepared from 50-100 mmol/L of glycine buffer solution, 50-80 mmol/L of sodium benzoate, 12/18 u/L of purine nucleoside phosphorylase, 30-40 u/L of xanthine oxidase, 200-300 u/L of peroxidase, 30-100 g/L of glyceraldehyde, 0.5 g/L of sodium azide, 10-200 mmol/L of disodium hydrogen phosphate, 100-300 mmol/L of KCl, 40-100 mmol/L of mannitol, 0.1-0.3 ml/L of preservative, 100-150 mmol/L of adenosine, 2-4 mmol/L of 4-aminoantipyrine, 10-15 mmol/L of color developing agent, 20-40 mmol/L of adenine nucleoside and 3-5 g/L of bovine serum albumin. The detection kit has the advantages of being high in determination precision, high in antijamming capacity, suitable for automated rapid determination and capable of creating favorable conditions for routine development of ADA detection application in clinic.

The invention relates to an adenosine monophosphate (AMP) adenosine deaminase for synthesizing and metabolizing an inosine monophosphate from adenine nucleotide of Cordyceps sinensis(Berk.)Sacc. Hirsutella sinensis from 'Bailing' production strain, a gene coding the enzyme and application thereof. The AMP adenosine deaminase comprises the proteins shown in SEQ ID No. 1 and SEQ ID No. 2, and the coding gene of the AMP adenosine deaminase corresponds to the nucleotide sequence shown in SEQ ID No. 3 and SEQ ID No.4. According to the invention, the metabolizing way for synthesizing the inosine monophosphate from the adenine nucleotide is researched in detail from the principle, and the cloned DNA containing the nucleotide sequence provided by the invention can be transferred to an engineering strain by transduction, transformation, and combined transfer; the expression of the gene is biologically synthesized by regulating the inosine monophosphate, the host inosine monophosphate is endowed with high expressivity, an effective way is provided for increasing the yield of the inosine monophosphate, and the invention has a great application prospect.