A B S T R A C T We have previously described a 14-yrold boy with hyperuricemia, renal failure, and accelerated purine production resistant in vivo and in vitro to purine analogs. This patient demonstrated normal red cell hypoxanthine-guanine phosphoribosyltransferase (HPRT) heat stability, electrophoresis at high pH, and activity at standard substrate levels. In the present report an abnormal H...

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, dimethyla...

A mutant form of human hypoxanthine-guanine phosphoribosyltransferase (HPRTToronto) was isolated from erythrocytes of a male patient with gout due to a partial deficiency of enzyme activity. The tryptic peptides of HPRTToronto were mapped by reverse-phase high pressure liquid chromatography in an attempt to define the precise abnormality in its primary structure. Sequence analysis of the single...

We isolated a strain of Escherichia coli K-12 in which the lac structural genes are fused to the purB control region and used this strain to study the regulation of the purA and purB loci. The purA locus was derepressed in response to either limiting adenine or guanine growth conditions in the presence of excess guanine or adenine, respectively. The presence of hypoxanthine in the culture mediu...

Thiopurines, Photolysis, Photooxygenation, Purine Derivatives Irradiation (A > 290 nm) of 6-thiopurine and some 9-substituted 6-thiopurines in oxygen saturated iertf-butanol leads to hypoxanthine, purine and purine-6-sulfonic acid or their substituted derivatives. Purine and hypoxanthine formation can be sensitized with dyes. The reaction of 6-thiopurine with singlet oxygen has also been perfor...

An HPLC method was developed to quantify the purines adenine and guanine and their metabolites xanthine and hypoxanthine in hydrolysates of isolated bacteria and omasal digesta and to assess the effect of using either purines only or purines plus metabolites as microbial markers for estimating microbial flow from the rumen. Individual purines and their metabolites were completely resolved on a ...