Hypoxanthine Guanine Phosphoribosyltransferase
Mostrando 1-12 de 146 artigos, teses e dissertações.
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1. Caracterização estrutural e bioquimica da hipoxantina-guanina-xantina fosforribosiltransferase / Biochemical and structural characterization of the hypoxanthine-guanine-xantina phosphoribosyltransferase
Os genes que codificam para a 6-oxopurina fosforribosiltransferase (HPRT, EC2.4.2.8) dos organismos Pyrococcus horikoshii e Schistosoma mansoni foram clonados em vetores de expressão. As proteínas foram expressas e purificadas em larga escala no sistema de expressão de Escherichia coli. Estudos cinéticos mostraram que a enzima de P. horikoshii é capaz d
Publicado em: 2008
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2. Crystal structure of Leishmania tarentolae hypoxanthine-guanine phosphoribosyltransferase (HGPRT) with bound GMP. / Estrutura cristalográfica da enzima hipoxantina-guanina fosforibosiltransferase (HGPRT) de Leishmania tarentolae complexada com GMP.
O presente trabalho teve como objetivos a clonagem, expressão e purificação da proteína HGPRT de Leishimania tarentolae, para a caracterização e cristalização dessa enzima, a fim do seu estudo estrutural e funcional. O gene da HGPRT foi amplificado a partir de uma biblioteca genômica de Leishmania tarentolae da cepa UC Lambda ZAP Express BamHI-Sal3A
Publicado em: 2003
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3. Hypoxanthine-guanine phosphoribosyltransferase: characteristics of the mutant enzyme in erythrocytes from patients with the Lesch-Nyhan syndrome
The Lesch-Nyhan syndrome is characterized clinically by choreoathetosis, spasticity, selfmutilation, and mental and growth retardation. Biochemically, there is a striking reduction of hypoxanthine-guanine phosphoribosyltransferase (HGPRT) activity in affected individuals. We have examined erythrocytes from 14 patients with the Lesch-Nyhan syndrome for the pr
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4. Regulation of purine utilization in bacteria. VI. Characterization of hypoxanthine and guanine uptake into isolated membrane vesicles from Salmonella typhimurium.
Uptake of hypoxanthine and guanine into isolated membrane vesicles of Salmonella typhimurium TR119 was stimulated by 5'-phosphoribosyl-1'-pyrophosphate (PRPP). For strain proAB47, a mutant that lacks guanine phosphoribosyltransferase, PRPP stimulated uptake of hypoxanthine into membrane vesicles. No PRPP-stimulated uptake of guanine was observed. For strain
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5. Partial purification and characterization of the mRNA for human thymidine kinase and hypoxanthine/guanine phosphoribosyltransferase.
We used direct microinjection of poly(A)+RNA into individual hypoxanthine/guanine phosphoribosyltransferase-deficient or thymidine kinase-deficient cells and detected the specific in vivo translation products as an assay for human hypoxanthine/guanine phosphoribosyltransferase or thymidine kinase mRNAs. The incorporation of [3H]hypoxanthine or [3H]thymidine
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6. Hypoxanthine-guanine phosphoribosyltransferase. Characterization of a mutant in a patient with gout.
The mutation in a young gouty male with a partial deficiency of hypoxanthine-guanine phosphoribosyltransferase has been evaluated. The serum uric acid was 11.8 mg/100 ml, and the urinary uric acid excretion was 1,279 mg/24 h. Erythrocyte hypoxanthine-guanine phosphoribosyltransferase was 34.2 nmol/h/mg, adenine phosphoribosyltransferase was 36.5 nmol/h/mg an
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7. Genetic modification of substrate specificity of hypoxanthine phosphoribosyltransferase in Salmonella typhimurium.
Salmonella typhimurium strain GP660 (proAB-gpt deletion, purE) lacks guanine phosphoribosyltransferase and hence cannot utilize guanine as a purine source and is resistant to inhibition by 8-azaguanine. Strain GP660 was mutagenized and a derivative strain (GP36) was isolated for utilization of guanine and hypoxanthine, but not xanthine, as purine sources. Th
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8. Effect of 6-thioguanine on Chlamydia trachomatis growth in wild-type and hypoxanthine-guanine phosphoribosyltransferase-deficient cells.
Chlamydiae have evolved a biphasic life cycle to facilitate their survival in two discontinuous habitats. The unique growth cycle is represented by two alternating forms of the organism, the elementary body and the reticulate body. Chlamydiae have an absolute nutritional dependency on the host cell to provide ribonucleoside triphosphates and other essential
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9. Overproduction of Uric Acid in Hypoxanthine-Guanine Phosphoribosyltransferase Deficiency: CONTRIBUTION BY IMPAIRED PURINE SALVAGE
The contribution of reduced purine salvage to the hyperuricemia associated with hypoxanthine-guanine phosphoribosyltransferase deficiency was measured by the intravenous administration of tracer doses of [8-14C]adenine to nine patients with normal enzyme activity, three patients with a partial deficiency of hypoxanthine-guanine phosphoribosyltransferase, and
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10. Proposed explanation for S-adenosylhomocysteine hydrolase deficiency in purine nucleoside phosphorylase and hypoxanthine-guanine phosphoribosyltransferase-deficient patients.
We have examined the basis for the recently reported, but unexplained deficiency of S-adenosylhomocysteine hydrolase (AdoHcyase) in the erythrocytes of patients with genetic deficiencies of purine nucleoside phosphorylase and hypoxanthine-guanine phosphoribosyltransferase. We found that a hemolysate from a patient with purine nucleoside phosphorylase deficie
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11. Expression of the Methanobacterium thermoautotrophicum hpt Gene, Encoding Hypoxanthine (Guanine) Phosphoribosyltransferase, in Escherichia coli
The hpt gene from the archaeon Methanobacterium thermoautotrophicum, encoding hypoxanthine (guanine) phosphoribosyltransferase, was cloned by functional complementation into Escherichia coli. The hpt-encoded amino acid sequence is most similar to adenine phosphoribosyltransferases, but the encoded enzyme has activity only with hypoxanthine and guanine. The s
American Society for Microbiology.
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12. Genetic Separation of Hypoxanthine and Guanine-Xanthine Phosphoribosyltransferase Activities by Deletion Mutations in Salmonella typhimurium
Certain proAB deletion mutants of Salmonella typhimurium were found to be simultaneously deleted in a gene required for the utilization of guanine and xanthine (designated gxu). These mutants were resistant to 8-azaguanine and when carrying an additional pur mutation were unable to use guanine or xanthine as a purine source. The defect was correlated with de