Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.17.1.4 (xanthine dehydrogenase)
 1,236 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The xanthine dehydrogenase of Clostridium acidiurici and C. cylindrosporum was assayed with methyl viologen as acceptor. In C. acidiurici the basal activity level was about 0.3 mumol/min x mg of protein. Cells grown on uric acid in the presence of 10(-7) M selenite showed a 14-fold increase in xanthine dehydrogenase activity, which decreased with higher selenite concentrations (10(-5) M). The supplementation with 10(-7) M molybdate or tungstate was without effect. High concentrations of tungstate decreased the xanthine dehydrogenase if selenite was also present. In comparison, high concentrations of molybdate affected only a small decrease in activity level at the optimal concentration for selenite and relieved to some degree the inhibitory effect of 10(-5) M selenite. With hypoxanthine and xanthine as substrates for growth again only the addition of selenite was necessary to show a similar increase in xanthine dehydrogenase activity. C. acidiurici could be grown in a mineral medium. Both xanthine dehydrogenase and formate dehydrogenase exhibited the highest level of activity if selenite and tungstate were present in that medium. In C. cyclindrosporum the basal activity level of xanthine dehydrogenase was about 0.95 mumol/min x mg of protein. The addition of 10(-7) M selenite to the growth medium increased the activity level about 3-fold, but the highest level (3.7 U/mg) was reached if 10(-7) M molybdate was also added. The presence of tungstate resulted in a decreased enzyme activity.
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PMID:Selenium requirement for active xanthine dehydrogenase from Clostridium acidiurici and Clostridium cylindrosporum. 51 33

An investigation, similar to our previously reported xanthine dehydrogenase study, was undertaken to examine the extent of hidden genic variation at nine loci (five larval proteins, three esterases and one aldehyde oxidase) by sequential application of various electrophoretic criteria employing pH, gel concentration and buffer variation. Polymorphic loci appear to fall into two distinct groups: weakly polymorphic, including larval protein 6, 7, 8, 10 and 13 and esterase-1 and -6; and highly polymorphic, including esterase-5, Xdh and possibly Ao. Monomorphic loci may belong to a third group different from all polymorphic loci. Bogota, a geographical isolate that is reproductively isolated from the mainland population, was found to be genetically distinct at four of the ten loci examined in detail so far, including Xdh, whereas previously it was found to be genetically distinct at none. These results are discussed in the light of balancing selection, neutral and mutation-selection hypotheses of genic variation in natural populations.
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PMID:Genic heterogeneity within electrophoretic "alleles" and the pattern of variation among loci in Drosophila pseudoobscura. 54 77

The amount of xanthine dehydrogenase (XDH), dihydrofolate reductase (DHFR), and lactate dehydrogenase (LDH) in crude extracts of 4- to 5-day-old adult Aedes aegypti was determined, and the properties of these enzymes were partially characterized. It was then found that the amount and other selected characteristics of XDH and LDH in extracts of female Ae. aegypti processed 5 to 7 days and 12 to 14 days after they had fed upon either normal or Brugia pahangi-infected jirds were indistinguishable from those of these two enzymes in extracts of female mosquitoes that did not have a blood meal. Under the same circumstances, the selected characteristics of DHFR were also unaffected. However, there was a suggestion that the amount of DHFR was slightly increased in extracts of female Ae. aegypti processed 5 to 7 days after they had fed upon B. pahangi-infected jirds; by 12 to 14 days after the blood meal, there was a consistent 30% to 60% increase in the amount of DHFR inextracts of infected mosquitoes. DHFR activity could not be detected in a similarly prepared extract of 4,000 to 5,000 infective (L-3) B. pagangi larvae, the approximate number present in the infected mosquito extracts. It would appear, therefore, that the increased amount of turnover of DHFR in the mosquito host occurs in response to advanced infection with B. pahangi.
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PMID:Comparative activity and properties of lactate dehydrogenase, xanthine dehydrogenase, and dihydrofolate reductase in normal and Brugia pagangi-infected Aedes aegypti. 55 68

Changes in hepatic purine enzyme activities of chicks fed diets containing 11%, 20%, 43% and 80% protein were correlated with protein intake and uric acid production in order to identify those enzymes with activities that parallel closely and may regulate uric acid production. Nucleoside phosphorylase, xanthine dehydrogenase, adenylosuccinate synthetase and adenosine kinase correlated positively with protein intake and uric acid production. Adenosine deaminase, 5'-nucleotidase (AMP), adenylate deaminase and adenine phosphoribosyltransferase correlated negatively with protein intake and uric acid production. Hypoxanthine phosphoribosyltransferase and 5'-nucleotidase (IMP) were unaffected by protein intake and did not correlate with uric acid production. The ratio of adenosine kinase to adenosine deaminase correlated positively with protein intake and uric acid production. The increased activities of adenylosuccinate synthetase and adenosine kinase, along with the reduced activities of 5'-nucleotidase and adenylate deaminase, in liver from chickens fed the 80% compared with the 11% protein diet demonstrate enhanced synthesis of adenine nucleotides. Since adenine nucleotides are essential cofactors for de novo purine synthesis, it is proposed that adenylosuccinate synthetase, adenosine kinase, 5'-nucleotidase and adenylate deaminase are key enzymes involved in the regulation of purine biosynthesis.
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PMID:Protein intake, hepatic purine enzyme levels and uric acid production in growing chicks. 61 42

1. Heavy-breed (HB) chicks differed from light-breed (LB) ones in their propensity to be overfed. Whereas in the LB chicks the amount by which they could be overfed reached 70% more than the food consumed daily by the ad lib.-fed chicks, in the HB chicks the maximal excess was only 13%. 2. Overfeeding caused a slight but statistically significant increase in the linear growth rate (shank length) of the LB chicks, with an opposite effect in the HB chicks. 3. Overfeeding increased the weight of the crop, proventriculus, small intestine, pancreas, liver and adipose tissue but had no such effect on the heart, cerebrum or cerebellum. 4. Overfeeding had no effect on the specific activities of the pancreatic digestive enzymes, liver xanthine dehydrogenase, or tryptophan oxygenase (EC 1.13.1.12). The increase in the total activities was due entirely to organ hypertrophy. 5. Obesity induced in young chicks had no residual effects on the adult LB chicks, but reduced the linear growth of the adult HB chicks. 6. An explanation for the difference between breeds in response to overfeeding at an early age is discussed.
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PMID:Influence of overfeeding on growth, obesity and intestinal tract in young chicks of light and heavy breeds. 61 76

Infusion of [14C]hypoxanthine into one renal portal circulation of the chicken resulted in an excess of [14C]uric acid excreted into the urine from the infused side kidney. No [14C]hypoxanthine appeared in the urine from either kidney. When the renal metabolism of [14C]hypoxanthine was inhibited by xanthine dehydrogenase inhibitors, almost no excess 14C-label appeared in the urine of the infused side suggesting that formation of nephrogenic urate plays an important role in the tubular excretion of hypoxanthine. A comparison of the effects of inhibitors on the renal excretion of preformed urate and nephrogenic urate suggests the existence of a p-aminohippurate-independent transport step for purines at the luminal membrane of the renal tubular cell. Studies with transport inhibitors suggest that the active transport step is anionic in character.
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PMID:The metabolism and active excretion of the hypoxanthine by the renal tubules in the chicken. 71 39

Two new mutants, deficient in aldehyde oxidase and xanthine dehydrogenase, have been isolated from a wild-type stock of Drosophila melanogaster and have been provisionally termed lxd-c and lxd-d, respectively, as both mutants appear to be allelic with lxd (low xanthine dehydrogenase). An analysis has been made of the effects of dietary molybdenum on lxd, lxd-c, lxd-d, lao (low aldehyde oxidase), mal (maroon-like eye color), and pac (Pacific) wild-type flies. On the lower dietary levels of 10(-3) M and 10(-2) M molybdenum, increases in specific activity of both enzymes were observed only in lxd. Furthermore, two- to three-fold increases in specific activity of both enzymes occurred in all strains, except mal, when cultured on 5 x 10(-2) M molybdenum. The lxd and lxd-c strains failed to survive on this high concentration of the ion. Similar concentrations of molybdenum had no effect in vitro. An extra electrophoretic band of xanthine dehydrogenase was observed on polyacrylamide gel from extracts of wild-type flies cultured on certain levels of molybdenum, but its appearance was not always correlated with the increases in specific activity.
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PMID:Nutritional control of xanthine dehydrogenase. II. Effects on xanthine dehydrogenase and aldehyde oxidase of culturing wild-type and mutant Drosophila on different levels of molybdenum. 80 86

The pleiotropic effect of the ma-1 mutation on the enzymes xanthine dehydrogenase and aldehyde oxidase in Drosophila melanogaster can most readily be explained by assuming that the enzymes share a subunit or cofactor whose synthesis is controlled by the ma-1 locus. According to this hypothesis a protein or a tightly bound cofactor common to both enzymes should be inactive or missing in the corresponding immunologically cross-reacting material found in ma-1 flies. Three of the proteins involved were purified by immunoadsorption: xanthine dehydrogenase, xanthine dehydrogenase cross-reacting material and aldehyde oxidase.
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PMID:Aldehyde oxidase and xanthine dehydrogenase from wild-type Drosophila melanogaster and immunologically cross-reacting material from ma-1 mutants. Purification by immunoadsorption and characterization. 81 50

Experiments expanding the array of mutants affecting the xanthine dehydrogenase (XDH) structural element in Drosophila melanogaster are described. These include rosy eye color mutants which exhibit interallelic complementation, and mutants with normal eye color but lowered levels of XDH. Evidence is presented which argues that these are structural alterations in the enzyme. Recombination experiments were performed using these mutants as well as some electrophoretic variants. The two ends of the rosy locus are marked with mutant sites which are clearly structural in nature; the XDH structural element and the rosy null mutant map are completely concordant. A possible procedure to recover control element mutants is described.
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PMID:Extension of the limits of the XDH structural element in Drosophila melanogaster. 82 44

Activities of glutamate and xanthine dehydrogenases were measured in four groups of quails (coturnix coturnix japonica): 1) hypodynamic birds which were kept in an area which made 1/4 of the control, 2) birds exposed to an increased weight load, 3) birds exposed to 3g. and 4) control birds. The experimental birds were exposed to the above treatment for 1 to 6 hours a day during 8 days. The birds were fed on a forced basis to eliminate differences in food intake. The activity of glutamate dehydrogenase was measured in the liver and that of xanthine dehydrogenase was assayed in the liver, kidneys and femoral muscle. It was found that increased gravity, weight load and hypodynamics affected the first and last stages in protein catabolism.
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PMID:[Effect of accelerations, additional weight load and hypokinesia on protein catabolism in the Japanese quail (Coturnix coturnix japonica)]. 83 7


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