4460 Human Hypoxanthine - Guanine
نویسندگان
چکیده
Hypoxanthine-guanine phosphoribosyltransferase (EC 2.4.2.8) has been purified 23,000-fold from normal human erythrocytes. The purification includes affinity chromatography on a GMP column. The subunit molecular weight of the enzyme obtained from this purification is 24,000. The finding of four protein species after cross-linkage of the highly purified enzyme with dimethylsuberimidate, dimethyladipimidate, and glutaraldehyde suggests that the enzyme may exist in the native state as a tetramer.
منابع مشابه
Prioritization of Deleterious Variations in the Human Hypoxanthine-Guanine Phosphoribosyltransferase Gene
ABSTRACT Background and Objectives: Non-synonymous single nucleotide polymorphisms are typical genetic variations that may potentially affect the structure or function of expressed proteins, and therefore could be involved in complex disorders. A computational-based analysis has been done to evaluate the phenotypic effect of no...
متن کاملHuman hypoxanthine-guanine phosphoribosyltransferase. IMP-GMP exchange stoichiometry and steady state kinetics of the reaction.
Steady state kinetics of hypoxanthine guanine phosphoribosyltransferase-catalyzed reactions are studied. The results obtained suggest that IMP, GMP, P-Rib-PP, and pyrophosphate bind to the same enzyme form, while hypoxanthine and guanine bind to a different form. Guanine activates IMP-pyrophosphorolysis. During the reaction guanine and IMP are consumed with formation of GM
متن کاملProposed 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 deficiency had only 7% of control AdoHcyase ...
متن کاملDevelopmental changes in purine phosphoribosyltransferases in human and rat tissues.
1. The hypoxanthine/guanine and adenine phosphoribosyltransferase activities in a wide variety of human tissues were studied during their growth and development from foetal life onward. A wide range of activities develop after birth, with especially high values in the central nervous system and testes. 2. Postnatal development of hypoxanthine/guanine phosphoribosyltransferase was also defined i...
متن کاملHypoxanthine-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 presence of hypoxanthine-guanine phosph...
متن کامل