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Regulation of purine hydroxylase and xanthine dehydrogenase from Clostridium purinolyticum in response to purines, selenium, and molybdenum.
J Bacteriol. 2002 Apr; 184(7):2039-44.JB

Abstract

The discovery that two distinct enzyme catalysts, purine hydroxylase (PH) and xanthine dehydrogenase (XDH), are required for the overall conversion of hypoxanthine to uric acid by Clostridium purinolyticum was unexpected. In this reaction sequence, hypoxanthine is hydroxylated to xanthine by PH and then xanthine is hydroxylated to uric acid by XDH. PH and XDH, which contain a labile selenium cofactor in addition to a molybdenum cofactor, flavin adenine dinucleotide, and FeS centers, were purified and partially characterized as reported previously. In the present study, the activities of these two enzymes were measured in cells grown in media containing various concentrations of selenite, molybdate, and various purine substrates. The levels of PH protein in extracts were determined by immunoblot assay. The amount of PH protein, as well as the specific activities of PH and XDH, increased when either selenite or molybdate was added to the culture medium. PH levels were highest in the cells cultured in the presence of either adenine or purine. XDH activity increased dramatically in cells grown with either xanthine or uric acid. The apparent increases in protein levels and activities of PH and XDH in response to selenium, molybdenum, and purine substrates demonstrate that these enzymes are tightly regulated in response to these nutrients.

Authors+Show Affiliations

Laboratory of Biochemistry, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892-8012, USA. selfw@nhlbi.nih.gov

Pub Type(s)

Journal Article

Language

eng

PubMed ID

11889113

Citation

Self, William T.. "Regulation of Purine Hydroxylase and Xanthine Dehydrogenase From Clostridium Purinolyticum in Response to Purines, Selenium, and Molybdenum." Journal of Bacteriology, vol. 184, no. 7, 2002, pp. 2039-44.
Self WT. Regulation of purine hydroxylase and xanthine dehydrogenase from Clostridium purinolyticum in response to purines, selenium, and molybdenum. J Bacteriol. 2002;184(7):2039-44.
Self, W. T. (2002). Regulation of purine hydroxylase and xanthine dehydrogenase from Clostridium purinolyticum in response to purines, selenium, and molybdenum. Journal of Bacteriology, 184(7), 2039-44.
Self WT. Regulation of Purine Hydroxylase and Xanthine Dehydrogenase From Clostridium Purinolyticum in Response to Purines, Selenium, and Molybdenum. J Bacteriol. 2002;184(7):2039-44. PubMed PMID: 11889113.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Regulation of purine hydroxylase and xanthine dehydrogenase from Clostridium purinolyticum in response to purines, selenium, and molybdenum. A1 - Self,William T, PY - 2002/3/13/pubmed PY - 2002/4/6/medline PY - 2002/3/13/entrez SP - 2039 EP - 44 JF - Journal of bacteriology JO - J Bacteriol VL - 184 IS - 7 N2 - The discovery that two distinct enzyme catalysts, purine hydroxylase (PH) and xanthine dehydrogenase (XDH), are required for the overall conversion of hypoxanthine to uric acid by Clostridium purinolyticum was unexpected. In this reaction sequence, hypoxanthine is hydroxylated to xanthine by PH and then xanthine is hydroxylated to uric acid by XDH. PH and XDH, which contain a labile selenium cofactor in addition to a molybdenum cofactor, flavin adenine dinucleotide, and FeS centers, were purified and partially characterized as reported previously. In the present study, the activities of these two enzymes were measured in cells grown in media containing various concentrations of selenite, molybdate, and various purine substrates. The levels of PH protein in extracts were determined by immunoblot assay. The amount of PH protein, as well as the specific activities of PH and XDH, increased when either selenite or molybdate was added to the culture medium. PH levels were highest in the cells cultured in the presence of either adenine or purine. XDH activity increased dramatically in cells grown with either xanthine or uric acid. The apparent increases in protein levels and activities of PH and XDH in response to selenium, molybdenum, and purine substrates demonstrate that these enzymes are tightly regulated in response to these nutrients. SN - 0021-9193 UR - https://www.unboundmedicine.com/medline/citation/11889113/Regulation_of_purine_hydroxylase_and_xanthine_dehydrogenase_from_Clostridium_purinolyticum_in_response_to_purines_selenium_and_molybdenum_ L2 - https://journals.asm.org/doi/10.1128/JB.184.7.2039-2044.2002?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub=pubmed DB - PRIME DP - Unbound Medicine ER -