作者:Paul S. Hinchliffe、J. Matthew Wood、Andrew M. Davis、Rupert P. Austin、R. Paul Beckett、Michael I. Page
DOI:10.1039/b208079f
日期:——
N-Acyl-β-sultams are time dependent irreversible active site directed inhibitors of elastase. The rate of inactivation is first order with respect to β-sultam concentration and the second order rate constants show a similar dependence on pH to that for the hydrolysis of a peptide substrate. Inactivation is due to the formation of a stable l â¶ l enzyme inhibitor complex as a result of the active site serine being sulfonylated by the β-sultam. Ring opening of the β-sultam occurs by SâN fission in contrast to the CâN fission observed in the acylation of elastase by N-acylsulfonamides. Structureâactivity effects are compared between sulfonylation of the enzyme and alkaline hydrolysis. Variation in 4-alkyl and N-substituted β-sultams causes differences in the rates of inactivation by 4 orders of magnitude.
N-Acyl-β-sultams 是一种时间依赖性不可逆的弹性蛋白酶活性位点定向抑制剂。失活速率与δ-²-舒坦浓度呈一阶关系,二阶速率常数与 pH 值的关系类似于肽底物的水解。失活是由于活性位点丝氨酸被δ-舒坦磺化,形成了稳定的lâ¶ l酶抑制剂复合物。与N-酰基磺酰胺酰化弹性蛋白酶时观察到的CâN裂变不同,δ-2-磺酰胺的开环是通过SâN裂变进行的。对酶的磺酰化和碱性水解的结构活性效应进行了比较。4-烷基和N-取代δ-磺酰胺的变化导致灭活速率相差4个数量级。