Anticancer agent 6-mercaptopurine (6MP) has been in use since 1953 for the treatment of childhood acute lymphoblastic leukemia (ALL) and inflammatory bowel disease. Despite being available for 60 years, several aspects of 6MP drug metabolism and pharmacokinetics in humans are unknown. Molybdoflavoenzymes such as aldehyde oxidase (AO) and xanthine oxidase (XO) have previously been implicated in ...

HEN extracts of wild-type Drosophila are electrophoresed on agar gels and the gels stained with a tetrazolium solution containing benzaldehyde, a formazan band is formed at a location not identical to the xanthine dehydrogenase (XDH) band ( COURTRIGHT 1966a). This was a surprising observation since benzaldehyde has been reported to serve as a substrate for XDH (GLASSMAN and MITCHELL 1959a). Sin...

Potassium oxonate, a selectively competitive uricase inhibitor, produced hyperuricemia (HUA) in rodents in a previous study. In this study, we employed the tree shrew as an animal model to study potassium oxonate-induced HUA. The effect of allopurinol (ALLO), a uric acid reducer, was also examined in this model. Potassium oxonate at doses of 5, 20, 40, 60, 80, 100, and 1,000 mg/kg was given int...

Acute lung injury represents a wide spectrum of pathologic processes, the most severe end of the spectrum being the acute respiratory distress syndrome. Reactive oxygen intermediates have been implicated as important in the pathobiochemistry of acute lung injury. The endogenous sources that contribute to the generation of reactive oxygen intermediates in acute lung injury are poorly defined but...

The rosy locus in Drosophila melanogaster codes for the enzyme xanthine dehydrogenase (XDH). Previous studies defined a "control element" near the 5' end of the gene, where variant sites affected the amount of rosy mRNA and protein produced. We have determined the DNA sequence of this region from both genomic and cDNA clones, and from the ry+10 underproducer strain. This variant strain had many...

Xylitol dehydrogenase (XDH) is one of the key enzymes in d-xylose metabolism, catalyzing the oxidation of xylitol to d-xylulose. Two copies of the XYL2 gene encoding XDH in the diploid yeast Candida tropicalis were sequentially disrupted using the Ura-blasting method. The XYL2-disrupted mutant, BSXDH-3, did not grow on a minimal medium containing d-xylose as a sole carbon source. An enzyme assa...

Anticancer agent 6-mercaptopurine (6MP) has been in use since 1953 for the treatment of childhood acute lymphoblastic leukemia (ALL) and inflammatory bowel disease. Despite being available for 60 years, several aspects of 6MP drug metabolism and pharmacokinetics in humans are unknown. Molybdoflavoenzymes such as aldehyde oxidase (AO) and xanthine oxidase (XO) have previously been implicated in ...

Xanthine dehydrogenase catalyzes the oxidation of hypoxanthine to xanthine and the further oxidation of xanthine to uric acid. The enzyme is the target of the anti-gout drug allopurinol and its involvement in postischemic reperfusion injury is presently being defined. Each subunit of the homodimeric 290 kDa enzyme contains four cofactors: one Mo-pterin, two [2Fe-2S] clusters and one FAD. Both t...

The baker's yeast Saccharomyces cerevisiae is generally classified as a non-xylose-utilizing organism. We found that S. cerevisiae can grow on D-xylose when only the endogenous genes GRE3 (YHR104w), coding for a nonspecific aldose reductase, and XYL2 (YLR070c, ScXYL2), coding for a xylitol dehydrogenase (XDH), are overexpressed under endogenous promoters. In nontransformed S. cerevisiae strains...

X A N T H I N E dehydrogenase (XDH) o€ Drosophila melamgaster is controlled by at least three loci. Electrophoretic evidence (YEN and GLASSMAN 1965) indicates that r y (rosy eye color, 3-52.4), a mutant that lacks XDH (GLASSMAN and MITCHELL 1959), is the structural gene for this enzyme. Mutants of the other two loci, ma-1 (maroon-like eye color, 1-64?) and lxd (low xanthine dehydrogenase, 3-33?...