title: The inhibition of bovine xanthine oxidase activity by Hg2+ and other metal ions.
abstract: The inhibition of the activity of bovine xanthine oxidase (XO) by divalent mercury and other metal ions has been investigated by optical spectroscopy and stop-flow kinetic measurements. The study shows that Hg2+ ion completely inhibits the activity of XO, while other metal ions such as Zn2+, Mg2+, Co2+, and Ni2+ inhibit the activity only marginally (approximately 10%). The inhibition by the Hg2+ ion was found to be monophasic and noncompetitive with strong affinity for binding to XO. The pH-dependent study of the inhibition indicates that at least two ionizing groups of XO are involved in the binding of the Hg2+ ion.
authors.affiliation: Chemical Physics Group, Tata Institute of Fundamental Research, Bombay, India.
authors.forename: M S
authors.initials: MS
authors.lastname: Mondal
authors.forename: S
authors.initials: S
authors.lastname: Mitra
mesh_terms: D000818:Animals; D002417:Cattle; D003300:Copper / Q000494:pharmacology; D005260:Female; D007700:Kinetics; D008628:Mercury / Q000494:pharmacology; D008670:Metals / Q000494:pharmacology*; D013053:Spectrophotometry / Q000379:methods; D014969:Xanthine Oxidase / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism
chemical_list: D008670:Metals; D003300:Copper; D014969:Xanthine Oxidase; D008628:Mercury