Biomaterial Database

Nitric oxide reversibly suppresses xanthine oxidase activity. 1994

M Fukahori, and K Ichimori, and H Ishida, and H Nakagawa, and H Okino

Department of Physiology 2, School of Medicine, Tokai University, Kanagawa, Japan.

The effects of nitric oxide (NO) on xanthine oxidase (XOD) activity and the site(s) of the redox center(s) affected were investigated. XOD activity was determined by superoxide (O2-) generation and uric acid formation. NO reversibly and dose-dependently suppressed XOD activity in both determination methods. The suppression interval also disclosed a dose-dependent prolongation. The suppression occurred irrespective of the presence or absence of xanthine; indicating that the reaction product of NO and O2-, peroxynitrite, is not responsible for the suppression. Application of synthesized peroxynitrite did not affect XOD activity up to 2 microM. Methylene blue, which is an electron acceptor from Fe/S center, prevented the NO-induced inactivation. The results indicate that NO suppresses XOD activity through reversible alteration of the flavin prosthetic site.

UI	MeSH Term	Description	Entries
D009569	Nitric Oxide	A free radical gas produced endogenously by a variety of mammalian cells, synthesized from ARGININE by NITRIC OXIDE SYNTHASE. Nitric oxide is one of the ENDOTHELIUM-DEPENDENT RELAXING FACTORS released by the vascular endothelium and mediates VASODILATION. It also inhibits platelet aggregation, induces disaggregation of aggregated platelets, and inhibits platelet adhesion to the vascular endothelium. Nitric oxide activates cytosolic GUANYLATE CYCLASE and thus elevates intracellular levels of CYCLIC GMP.	Endogenous Nitrate Vasodilator,Mononitrogen Monoxide,Nitric Oxide, Endothelium-Derived,Nitrogen Monoxide,Endothelium-Derived Nitric Oxide,Monoxide, Mononitrogen,Monoxide, Nitrogen,Nitrate Vasodilator, Endogenous,Nitric Oxide, Endothelium Derived,Oxide, Nitric,Vasodilator, Endogenous Nitrate
D010084	Oxidation-Reduction	A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).	Redox,Oxidation Reduction
D004789	Enzyme Activation	Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.	Activation, Enzyme,Activations, Enzyme,Enzyme Activations
D013054	Spectrophotometry, Atomic	Spectrophotometric techniques by which the absorption or emmision spectra of radiation from atoms are produced and analyzed.	Spectrophotometry, Atomic Absorption,AA Spectrophotometry,AE Spectrophotometry,Atomic Absorption Spectrophotometry,Atomic Emission Spectrophotometry,Atomic Spectrophotometry,Inductively Coupled Plasma Atomic Emission Spectrophotometry,Inductively Coupled Plasma Atomic Emission Spectroscopy,Spectrophotometry, Atomic Emission,AA Spectrophotometries,AE Spectrophotometries,Absorption Spectrophotometry, Atomic,Emission Spectrophotometry, Atomic,Spectrophotometries, AA,Spectrophotometries, AE,Spectrophotometry, AA,Spectrophotometry, AE
D014969	Xanthine Oxidase	An iron-molybdenum flavoprotein containing FLAVIN-ADENINE DINUCLEOTIDE that oxidizes hypoxanthine, some other purines and pterins, and aldehydes. Deficiency of the enzyme, an autosomal recessive trait, causes xanthinuria.	Hypoxanthine Oxidase,Hypoxanthine Dehydrogenase,Hypoxanthine-Xanthine Oxidase,Purine-Xanthine Oxidase,Dehydrogenase, Hypoxanthine,Hypoxanthine Xanthine Oxidase,Oxidase, Hypoxanthine,Oxidase, Hypoxanthine-Xanthine,Oxidase, Purine-Xanthine,Oxidase, Xanthine,Purine Xanthine Oxidase