Xanthine oxidase converts nitric oxide to nitroxyl that inactivates the enzyme |
| |
Authors: | Saleem Mohammad Ohshima Hiroshi |
| |
Institution: | International Agency for Research on Cancer, 150 Cours Albert Thomas, 69372 Lyon Cedex 08, France. |
| |
Abstract: | Xanthine oxidase (XO) was found to convert nitric oxide (NO* ) released from spermine-NONOate to nitroxyl (HNO), the one-electron reduction product of NO*, in the presence of its substrate hypoxanthine under anaerobic conditions. Under these conditions, XO lost its activity. Upon aerobic incubation of XO with its substrate, neither conversion of NO* to HNO nor inactivation of the enzyme was observed. Angeli's salt (an HNO generator) or synthetic peroxynitrite inactivated XO at low concentrations, whereas high concentrations of diethylamine-NONOate (an NO* donor) and SIN-1 (which generates peroxynitrite by releasing both NO* and superoxide) were required to inactivate XO. These results suggest that HNO generated by XO under anaerobic conditions inactivates XO. As both XO and NO* synthase are activated and/or induced in ischemia-reperfusion injury, HNO formed by XO may contribute to pathogenesis by exerting its potent oxidation activity against a variety of biological compounds. |
| |
Keywords: | Xanthine oxidase Nitric oxide Nitroxyl Angeli’s salt Peroxynitrite |
本文献已被 ScienceDirect PubMed 等数据库收录! |
|