Peroxygenation mechanism for chloroperoxidase-catalyzed N-oxidation of arylamines.
Peroxygenation mechanism for chloroperoxidase-catalyzed N-oxidation of arylamines.
复制标题
氯过氧化物酶催化芳胺 N-氧化的过氧化机制。
DOI：
10.1021/tx00023a011
复制
发表时间：
1991
影响因子：
4.1
通讯作者：
Corbett,MD
中科院分区：
文献类型：
--
作者：
Doerge,DR;Corbett,MD
在过氧化酶氯过氧化物酶（CPX）和豌豆过氧化物酶（PSM）中的每一种存在下，用正常H2 O2和用180标记的H2 O2进行H2 O2对三种芳基胺底物的代谢。用GC-MS方法检测了C-亚硝基芳香代谢产物的180掺入量。芳胺底物为对甲苯胺、4-氯苯胺和3，4-二氯苯胺。对于这两种酶，当[180] H2 O2是氧化剂底物时，发现所有三种芳基胺都定量掺入180到它们的亚硝基代谢物中。发现氧原子引入到4-氯亚硝基苯中发生在该方法的第一步，因为发现当（4-氯苯基）羟胺用作底物时，没有发生180的显著引入。这些观察结果证明，CPX和PSM通过从化合物I活化形式的血红素官能团的氧转移引起伯芳胺的N-氧化。因此，当这些过氧化物酶以这种方式起作用时，它们被正确地称为过氧合酶。过氧化物酶的反应机制和它们的关系，细胞色素P-450氧化的讨论。
The metabolism of three arylamine substrates by H202 in the presence of each of the per-oxidative enzymes chloroperoxidase (CPX) and peaseed peroxygenase (PSM) was conducted with normal H202 and with 180-labeled H202. The resulting C-nitroso aromatic metabolites were examined byGC-MS methods to determine the extent of 180 incorporation. The arylamine substrates were p-toluidine, 4-chloroaniline, and 3, 4-dichloroaniline. For both enzymes, all three arylamines were found to give quantitative incorporation of 180 into their nitroso metabolites when [180] H202 was the oxidant substrate. The introduction of the oxygen atom into 4-chloronitrosobenzene was found to occur during the first step of this process, since it was found that when (4-chlorophenyl) hydroxylamine was employed as the substrate, no significant in-corporation of 180 occurred. These observations prove that CPX and PSM cause N-oxidation of primary arylamines via an oxygen transfer from the compound I activated forms of their heme functional groups. Therefore, these peroxidases are correctly called peroxygenases when acting in such a manner. A discussion of the reaction mechanisms for peroxidases and their relation to cytochrome P-450 oxidations is presented.