Serra M A, Pintar A, Casella L, Sabbioni E
Commission of the European Communities, Joint Research Centre, Environment Institute, Ispra, Italy.
J Inorg Biochem. 1992 May 15;46(3):161-74. doi: 10.1016/0162-0134(92)80027-s.
The effect of vanadium (V) on the activity of horseradish peroxidase, catalase, glutathione peroxidase, and superoxide dismutase has been studied. A competitive inhibition pattern was evident for vanadate ions on the activity of horseradish peroxidase (Ki = 41.2 microM). No significant inhibitory effects were found when V(V) was tested with catalase and when either V(IV) or V(V) were assayed with glutathione peroxidase. For the latter, the effect of V on the different components of the reaction system was investigated. V(V) did not significantly affect SOD activity when assayed with the sulfite method, which is devoid of interferences with V(V); however, there was an apparent inhibitory dose-response pattern for either V(IV) or V(V) using the pyrogallol assay, owing to an interference of pyrogallol with the metal. Besides, no significant binding of V(IV) or V(V) to the enzyme could be demonstrated. The lack of a direct inhibitory effect of V on the activity of the main antioxidant enzymes suggests that many biological and toxicological effects of V may be mediated more by oxidative reactions of the metal or of its complexes with physiologically relevant biomolecules than by a direct modulation of enzymatic activities.
研究了钒（V）对辣根过氧化物酶、过氧化氢酶、谷胱甘肽过氧化物酶和超氧化物歧化酶活性的影响。钒酸根离子对辣根过氧化物酶活性呈现出竞争性抑制模式（Ki = 41.2 microM）。用V（V）检测过氧化氢酶以及用V（IV）或V（V）检测谷胱甘肽过氧化物酶时，均未发现显著的抑制作用。对于后者，研究了V对反应体系不同组分的影响。用亚硫酸盐法检测时，V（V）对超氧化物歧化酶活性无显著影响，该方法不受V（V）干扰；然而，使用邻苯三酚法时，V（IV）或V（V）呈现出明显的抑制剂量反应模式，这是由于邻苯三酚与金属存在干扰。此外，未证明V（IV）或V（V）与该酶有显著结合。V对主要抗氧化酶活性缺乏直接抑制作用，这表明V的许多生物学和毒理学效应可能更多地是由金属或其与生理相关生物分子形成的络合物的氧化反应介导的，而非通过直接调节酶活性。
