Mechanism-based inactivation of N-arylhydroxamic acid N,O-acyltransferase by 7-substituted-N-hydroxy-2-acetamidofluorenes
作者:Virginia C. Marhevka、Nancy A. Ebner、Russell D. Sehon、Patrick E. Hanna
DOI:10.1021/jm00379a005
日期:1985.1
N-Arylhydroxamic acid N,O-acyltransferase (AHAT) catalyzes the transfer of the N-acetyl group from N-arylhydroxamic acids to arylamines. In the absence of an arylamine acceptor, AHAT catalyzes the conversion of N-arylhydroxamic acids to reactive electrophilic intermediates that become irreversibly bound to cellular nucleophiles, including those present on AHAT itself. As part of an investigation of
N-芳基异羟肟酸N,O-酰基转移酶(AHAT)催化N-乙酰基从N-芳基异羟肟酸转移至芳基胺。在不存在芳基胺受体的情况下,AHAT催化N-芳基异羟肟酸转化为反应性亲电中间体,该中间体不可逆地与细胞亲核试剂(包括AHAT本身上存在的亲核试剂)结合。作为AHAT催化生物活化过程研究的一部分,合成了N-羟基-2-乙酰氨基芴(1)的一系列7-取代类似物,并在体外评估了部分纯化的仓鼠肝AHAT制剂的底物和灭活剂。所有这些化合物在AHAT催化的4-氨基偶氮苯(AAB)的反乙酰化中均充当乙酰基供体,并且它们都是AHAT的失活剂。失活过程表现出明显的一级动力学,而7-甲氧基化合物表现出最大的失活速率常数。定量结构活性分析为该系列化合物使AHAT失活涉及带正电荷的物种这一概念提供了支持。与AHAT和N-芳基异羟肟酸的培养混合物中包括谷胱甘肽,半胱氨酸,蛋氨酸,磷酸鸟苷和tRNA等亲核捕获剂的实验结果表明,从酶