Xanthine dehydrogenase (XDH) and aldehyde oxidase (AO) in Drosophila melanogaster require for their activity the action of another unlinked locus, maroon-like (mal). While the XDH and AO loci are on chromosome 3, mal maps to the X chromosome. Although functional mal gene product is required for XDH and AO activity, it is possible to examine the effects of mutant mal alleles in those cases when ...

The enzyme xanthine oxidoreductase (XOR) is an important source of oxygen free radicals and related postischemic injury. Xanthine dehydrogenase (XDH), the major form of XOR in tissues, can be converted to xanthine oxidase (XO) by oxidation of sulfhydryl residues or by proteolysis. The conversion of XDH to XO has been assumed to be required for radical generation and tissue injury. It is also po...

The enzyme xanthine oxidase (XO) has been implicated in the pathogenesis of several disease processes, such as ischemia-reperfusion injury, because of its ability to generate reactive oxygen species. The expression of XO and its precursor xanthine dehydrogenase (XDH) is regulated at pre- and posttranslational levels by agents such as lipopolysaccharide and hypoxia. Posttranslational modificatio...

Xanthine dehydrogenase (XDH), a complex molybdo/iron-sulfur/flavoprotein, catalyzes the oxidation of hypoxanthine to xanthine followed by oxidation of xanthine to uric acid with concomitant reduction of NAD+. The 2.7 A resolution structure of Rhodobacter capsulatus XDH reveals that the bacterial and bovine XDH have highly similar folds despite differences in subunit composition. The NAD+ bindin...

These studies examined the effect of dicumarol on xanthine dehydrogenase (XDH), an enzyme recently shown to bioreduce mitomycin C. Dicumarol, which has previously been shown to inhibit xanthine oxidase (XO), inhibited both XDH and XO mediated conversion of xanthine to uric acid but potentiated the metabolism of mitomycin C by XDH and XO. Formation of 2,7-diaminomitosene following mitomycin C bi...

Sixty-two isochromosomal lines of D. melanogaster were screened for cryptic electrophoretic variation at the xanthine dehydrogenase (XDH) locus. Sequential polyacrylamide vertical slab gel electrophoresis was performed using four electrophoretic criteria. A total of 15 classes of electromorphs were revealed. D. melanogaster appears to exhibit as much polymorphism at this locus as other extensiv...

The rosy gene in Drosophila melanogaster codes for the enzyme xanthine dehydrogenase (XDH). Mutants that have no enzyme activity are characterized by a brownish eye color phenotype reflecting a deficiency in the red eye pigment. Xanthine dehydrogenase is not synthesized in the eye, but rather is transported there. The present report describes the ultrastructural localization of XDH in the Droso...

Sequential polyacrylamide electrophoresis has revealed 20 allozymes of xanthine dehydrogenase (XDH) in Drosophila pseudoobscura. DNA sequence determination of seven isolates of the Xdh locus that represent six allozyme classes are presented here. Of the 5,456 sites examined, 180 are polymorphic, with 27 polymorphisms occurring at nonsynonymous, or replacement, sites. An average of nine amino ac...

Phosphogluconate dehydrogenase (PGD) and xanthine dehydrogenase (XDH) were genetically studied by agar gel electrophoresis in the mosquito Aedes togoi. Adult homogenates displayed banding patterns with one zone of activity of either enzyme. Eight backcrosses were conducted to map the two loci, Pgd and Xdh, to linkage group III with the following arrangement: Pgd--(ca. 15 map units)--bl (bleache...

Milk xanthine oxidase (XO) has been prepared in a dehydrogenase form (XDH) by purifying the enzyme in the presence of 2.5 mM dithiothreitol. Unlike XO, which reacts rapidly only with oxygen and not with NAD, the XDH form of the enzyme reacts rapidly with NAD. XDH has a turnover number for the NAD-dependent conversion of xanthine to urate of 380 mol/min/mol at pH 7.5, 25 degrees C, with a Km = <...