铂（II）配合物对二氢蝶啶还原酶（人脑）的失活作用。

Inactivation of dihydropteridine reductase (human brain) by platinum(II) complexes.

作者信息

Armarego W L, Ohnishi A

出版信息

Eur J Biochem. 1987 Apr 15;164(2):403-9. doi: 10.1111/j.1432-1033.1987.tb11072.x.

DOI:10.1111/j.1432-1033.1987.tb11072.x

Abstract

Potassium tetrachloroplatinate (K2PtCl4) inactivates dihydropteridine reductase from human brain in a time-dependent and irreversible manner. The inactivation has been followed by measuring enzyme activity and fluorescence changes. The enzyme is completely protected from inactivation by NADH, the pterin cofactor [quinonoid 6-methyl-7,8-dihydro(6H)pterin] and dithiothreitol. Evidence is presented that K2PtCl4 reacts at the active site and that (a) thiol group(s) is involved in, or is masked by, this reaction. K2PtCl4 is a stronger inhibitor of human brain dihydropteridine reductase that cis- and trans-diaminodichloroplatinum, cis-dichloro[ethylenediamine]platinum and K4Fe(CN)6, whereas H2PtCl6 is considerably weaker and (Ph3P)3RhCl is inactive.

摘要

四氯铂酸钾（K2PtCl4）以时间依赖性和不可逆的方式使来自人脑的二氢蝶啶还原酶失活。通过测量酶活性和荧光变化来跟踪这种失活过程。该酶受到NADH、蝶呤辅因子[醌型6-甲基-7,8-二氢（6H）蝶呤]和二硫苏糖醇的完全保护而不会失活。有证据表明K2PtCl4在活性位点发生反应，并且该反应涉及一个或多个巯基基团，或者巯基基团被该反应所掩盖。K2PtCl4是比顺式和反式二氨基二氯铂、顺式二氯[乙二胺]铂和K4Fe(CN)6更强的人脑二氢蝶啶还原酶抑制剂，而H2PtCl6的抑制作用则弱得多，并且（三苯基膦）3RhCl无活性。