过氧亚硝酸盐分解过程中超氧自由基产生的证据。

Evidence for superoxide radical production in peroxynitrite decomposition.

作者信息

Zang L Y, Shi X

机构信息

Laboratory of Experimental Pathology, National Cancer Institute, NIH, Bethesda, MD 20892-0041, USA.

出版信息

Biochem Mol Biol Int. 1995 Oct;37(2):355-60.

PMID:8673019

Abstract

Peroxynitrite decomposition was investigated by ESR spin trapping. The spin trap used was 5,5-dimethyl-1-pyrroline N-oxide (DMPO). A mixture of peroxynitrite and DMPO generated predominantly DMPO-O2- adduct. A combination of SOD and catalase suppressed the formation of DMPO-O2-. The DMPO-O2- signal reached its maximum at pH lower than 7 and decreased as pH increased. The DMPO-O2- signal also depended on peroxynitrite concentration with maximum signal intensity appearing at 4.2 mM. The results demonstrate that peroxynitrite decomposition generates O2.-. Since reaction of H2O2 with NO2- generates peroxynitrite, the results point out a pathway for conversion of H2O2 to O2.- via peroxynitrite as an intermediate.

摘要

通过电子顺磁共振（ESR）自旋捕获技术研究了过氧亚硝酸盐的分解。所使用的自旋捕获剂是5,5 - 二甲基 - 1 - 吡咯啉N - 氧化物（DMPO）。过氧亚硝酸盐和DMPO的混合物主要生成DMPO - O₂⁻加合物。超氧化物歧化酶（SOD）和过氧化氢酶的组合抑制了DMPO - O₂⁻的形成。DMPO - O₂⁻信号在pH低于7时达到最大值，并随着pH值的升高而降低。DMPO - O₂⁻信号还取决于过氧亚硝酸盐的浓度，最大信号强度出现在4.2 mM时。结果表明，过氧亚硝酸盐分解产生O₂⁻。由于H₂O₂与NO₂⁻反应生成过氧亚硝酸盐，结果指出了一条通过过氧亚硝酸盐作为中间体将H₂O₂转化为O₂⁻的途径。