Glutathione-analogous peptidyl phosphorus esters as mechanism-based inhibitors of γ-glutamyl transpeptidase for probing cysteinyl-glycine binding site
作者:Mado Nakajima、Bunta Watanabe、Liyou Han、Bun-ichi Shimizu、Kei Wada、Keiichi Fukuyama、Hideyuki Suzuki、Jun Hiratake
DOI:10.1016/j.bmc.2013.12.034
日期:2014.2
and irreversibly by the peptidyl phosphorus esters with a good leaving group (phenoxide). Human GGT was highly selective for l-aliphatic amino acid such as l-2-aminobutyrate (l-Cys mimic) at the Cys binding site, whereas E. coli GGT significantly preferred l-Phe mimic at this site. The C-terminal Gly and a l-amino acid analogue at the Cys binding site were necessary for inhibition, suggesting that
γ-谷氨酰转肽酶(GGT)催化谷胱甘肽及其S-缀合物的γ-谷氨酰键断裂,通过谷胱甘肽体内稳态参与许多生理和病理学过程。定义其Cys-Gly结合位点不仅在定义GGT的生理功能方面非常重要,而且在设计用于药物目的的特异性和有效抑制剂方面也非常重要。在这里,我们报告合成和评估一系列谷胱甘肽类似肽基磷酸酯作为人和大肠杆菌的基于机理的抑制剂用于探测Cys-Gly结合位点的结构和立体化学偏好的GGT。具有良好离去基团(酚盐)的肽基磷酸酯均强烈且不可逆地抑制了这两种酶。人类GGT是为高度选择性升-脂族氨基酸如升-2-氨基丁酸(升-Cys模拟物)在半胱氨酸结合位点,而大肠杆菌GGT显著优选升在此位点-Phe模拟物。C末端结合位点的C末端Gly和一个1-氨基酸类似物是抑制所必需的,这表明人GGT对谷胱甘肽(γ-Glu- 1 -Cys-Gly)具有高度选择性。GGT对谷胱甘肽没有选择性,但仍保留了二肽(1 -