13 results about "Nucleoside phosphorylase" patented technology

The invention discloses a synthesis method of 2 '-fluoro-2'-deoxyguanosine. According to the method, thymine nucleoside phosphorylase and purine nucleoside phosphorylase are used as biocatalysts, and 2 '-fluoro-2'-deoxyuridine and guanine are used as substrates to synthesize the 2 '-fluoro-2'-deoxyguanosine. Compared with a chemical method, the production cost is greatly reduced; meanwhile, the synthesis method can effectively solve the problem that the product is difficult to separate.

Compositions and methods relating to a pharmacological therapy for a human genetic disease, specifically mitochondrial DNA depletion-deletions syndromes, and more specifically, those related to mutations in the GUK1 gene. The pharmacological therapy involves the administration of deoxyguanosine (dG), a purine nucleoside phosphorylase (PNP) inhibitor, including but not limited to forodesine, or both.

The invention discloses an application of cold adaptability purine nucleoside phosphorylase in biosynthesis of nucleoside compounds. According to the invention, the cold adaptability purine nucleoside phosphorylase ColPNP from Colwellia is screened and obtained, and the cold adaptability purine nucleoside phosphorylase ColPNP, ribose kinase EcRK from escherichia coli and phosphopentose mutase EcPPM from escherichia coli can jointly form a multi-enzyme cascade catalytic system to efficiently catalyze synthesis of nucleoside compounds. The cold adaptability purine nucleoside phosphorylase ColPNP screened by the invention has a relatively low optimum temperature which is similar to the optimum temperature of EcRK and EcPPM, can improve the synthesis efficiency of nucleoside compounds, and has a wide application prospect in the aspect of preparing virus infection and tumor nucleoside compounds.

The application discloses a monomerized pyrimidine nucleoside phosphorylase mutant and a construction method and application thereof, and belongs to the field of enzyme engineering and biological catalysis technology.The mutant is obtained by amino acid substitution mutation of wild-type pyrimidine nucleoside phosphorylase shown in SEQ ID NO:1, and the amino acid sequence is shown in SEQ ID NO:2.The mutant is transformed into a stable monomer form by dimer interface remodeling and hinge region stabilization of the closed active conformation, the natural dimer PyNP is transformed into a stable monomer form, and the catalytic activity of the mutant to uridine, 2'-deoxyuridine and similar substrates is maintained in the monomer state.Compared with the wild-type enzyme, the mutant has lower oligomer dependence, better temperature stability, pH stability and storage stability, and can be used for biological catalytic synthesis of nucleosides and nucleoside analogs.

This disclosure relates to the use of Purine Nucleoside Phosphorylase (PNP) inhibitors such as ulodesine and its salts, in the treatment and / or prevention of diseases associated with nicotinamide adenine dinucleotide (NAD+) depletion, including diseases of mitochondrial dysfunction (including neurodegeneration and peripheral neuropathies), the preservation of cognitive function and in muscular disorders such as sarcopenia; and in metabolic syndrome and associated conditions. In particular the disclosure provides the use of PNP inhibitors such as ulodesine in the treatment of neurodegenerative conditions such as Parkinson's disease and amyotrophic lateral sclerosis.

The present invention provides a pyrimidine nucleoside phosphorylase mutant and a method for producing 2'-fluoronucleosides. Here, the pyrimidine nucleoside phosphorylase mutant includes (a) a protein resulting from a mutation based on the pyrimidine nucleoside phosphorylase wild-type enzyme TtPyNP represented by SEQ ID NO: 1, wherein the mutation is selected from one or more mutations such as K80, or (b) a protein having 70% or more homology to the amino acid sequence limited in (a) and possessing purine nucleoside phosphorylase activity. This can solve the problem in conventional techniques of low production yield of 2'-fluoronucleosides synthesized under catalytic conditions and is applicable to the field of enzyme catalysis.

Provide is a purine nucleoside phosphorylase mutant and a method for preparing a 2'-fluoronucleoside. The purine nucleoside phosphorylase mutant includes: (a) a protein with a mutation based on the purine nucleoside phosphorylase wild-type enzyme GsPNP as shown in SEQ ID NO: 3, where the mutation is selected from any one or more of the following mutations: L148, P19, Q41, etc.; or (b) a protein that has greater than 70% identity to the amino acid sequence as defined in (a) and has a purine nucleoside phosphorylase activity. The present application solves the problem of low yield in enzyme-catalyzed synthesis of 2'-fluoronucleoside in the prior art and is suitable for the field of enzyme catalysis.

The present application provides a method for enzymatic synthesis of a nucleoside bearing a protecting group, and a composition. The method includes: using pyrimidine nucleoside phosphorylase or uracil nucleoside phosphorylase and purine nucleoside phosphorylase to catalyze a substrate to synthesize a nucleoside bearing a protecting group, where the substrate includes a substrate nucleoside, a substrate base and a substrate phosphate, and the substrate base bears a protecting group; the pyrimidine nucleoside phosphorylase includes a protein that is of more than 80% identity to a protein PyNP shown in SEQ ID NO: 1; the uracil nucleoside phosphorylase includes a protein that is of more than 80% identity to a protein UP shown in SEQ ID NO: 2; and the purine nucleoside phosphorylase includes a protein that is of more than 80% identity to a protein PNP shown in SEQ ID NO: 3, 7 or 8. The present application can solve the problem that there is no biosynthesis method to produce a nucleoside bearing a protecting group in the prior art, and thus is suitable for the field of the enzymatic synthesis.

The invention relates to the technical field of biology, in particular to a preparation and purification method of 2 '-fluoro-2'-deoxyguanosine. The invention discloses a preparation and purification method of 2 '-fluoro-2'-deoxyguanosine.The preparation method comprises the following steps that 2, 6-diaminopurine and 2 '-fluoro-2'-deoxyuridine generate 2 '-fluoro-2, 6-diaminopine-2'-deoxynucleoside under the catalysis of thymine nucleoside phosphorylase and purine nucleoside phosphorylase, filtering is conducted, and the 2 '-fluoro-2, 6-diaminopine-2'-deoxyguanosine is obtained. Then adenosine deaminase is added for catalysis, and 2 '-fluoro-2'-deoxyguanosine is generated; biosynthesis of the 2 '-fluoro-2'-deoxyguanosine is divided into two stages, the intermediate 2 '-fluoro-2, 6-diaminopine-2'-deoxynucleoside is synthesized firstly, and then deamination is performed to form the 2 '-fluoro-2'-deoxyguanosine, so that the problem that the conversion rate is extremely low when guanine with low solubility is taken as a substrate is solved.

This invention belongs to the fields of chemical pharmaceuticals, neurosurgery, and oncology therapeutics, specifically relating to the application of purine nucleoside phosphorylase inhibitors (PNP inhibitors) such as Forodesine or its pharmaceutically acceptable salts in the treatment of brain tumors, including the use of Forodesine or its pharmaceutically acceptable salts in inhibiting glioma growth and promoting anti-tumor immunity. It also relates to a novel treatment method for gliomas. Through extensive exploratory experiments, the applicant of this invention has for the first time discovered that Forodesine or its pharmaceutically acceptable salts can inhibit glioma growth by enhancing anti-tumor immunity, exhibiting inhibitory effects on glioma cells. Therefore, Forodesine or its pharmaceutically acceptable salts can serve as potential drugs for the treatment of brain tumors.

This invention discloses a purine nucleoside phosphorylase mutant and its application in the preparation of nicotinamide ribomatate. The PNP mutant is a substitution of at least one amino acid residue from the wild-type PNPLf derived from *Leptodactylus fuscus*, specifically serine at position 244, threonine at position 247, and alanine at position 290, preferably the S244Y / T247W / A290F triple mutant. This invention also provides a one-pot enzymatic method for preparing NR malate, using inosine and nicotinamide as substrates. The PNP mutant catalyzes a phosphorylation-transglycosylation tandem reaction to generate NR, which is then reacted with malic acid in situ to form NR malate. The NR yield can reach over 92%, and the total yield of NR malate can reach over 82%. This method is green, efficient, highly selective, and simplified, avoiding the large-scale use of organic solvents, making it suitable for industrial production.

This invention relates to the field of microbial technology, specifically disclosing a fermentation method for producing threonine and the application of nucleoside phosphorylase activity in inactivated or weakened microorganisms in threonine production. The invention discovered that the activity of nucleoside phosphorylase in inactivated or weakened microorganisms can increase the yield of threonine produced by fermentation. Therefore, a fermentation method for producing L-threonine is proposed, which uses recombinant microorganisms for fermentation. Compared to the starting strain, the recombinant microorganisms exhibit reduced or inactivated nucleoside phosphorylase activity. The amino acid sequence of the nucleoside phosphorylase is shown in any one of SEQ ID No. 28-30. This invention provides a new and effective method for threonine production.

The invention relates to the technical field of biology, in particular to a thymine phosphorylase mutant and application thereof. The invention provides a thymine nucleoside phosphorylase mutant derived from Escherichia coli and an application of the thymine nucleoside phosphorylase mutant in catalytic synthesis reaction of nucleoside compounds. Compared with wild type thymine phosphorylase, the 14 thymine phosphorylase mutants with excellent performance provided by the invention show more excellent thermal stability and synthesis activity of catalyzing non-natural nucleoside, and can be applied to industrial production and manufacturing of non-natural nucleoside biosynthesis.