Design of Inhibitors of Orotidine Monophosphate Decarboxylase Using Bioisosteric Replacement and Determination of Inhibition Kinetics
作者:Ewa Poduch、Angelica M. Bello、Sishi Tang、Masahiro Fujihashi、Emil F. Pai、Lakshmi P. Kotra
DOI:10.1021/jm060202r
日期:2006.8.1
Inhibitors of orotidine monophosphate decarboxylase (ODCase) have applications in RNA viral, parasitic, and other infectious diseases. ODCase catalyzes the decarboxylation of orotidine monophosphate (OMP), producing uridine monophosphate (UMP). Novel inhibitors 6-amino-UMP and 6-cyano-UMP were designed on the basis of the substructure volumes in the substrate OMP and in an inhibitor of ODCase, barbituric
酪蛋白单磷酸脱羧酶(ODCase)抑制剂可用于RNA病毒,寄生虫和其他传染病。ODCase催化牛尿苷单磷酸酯(OMP)的脱羧,产生尿苷单磷酸酯(UMP)。根据底物OMP和ODCase抑制剂巴比妥酸单磷酸酯BMP中亚结构的体积设计了新型抑制剂6-氨基-UMP和6-氰基-UMP。为了研究ODCase的抑制动力学,开发了一种使用等温滴定热法(ITC)的新酶分析方法。反应速率是通过监测在酪蛋白单磷酸的酪蛋白的脱羧反应过程中产生的热量来测量的。确定了动力学参数(k(cat)= 21 s(-1),KM = 5 microM)和摩尔焓(DeltaH(app)= 5 kcal / mol),用于通过ODCase进行底物的脱羧。观察到该酶的竞争性抑制,并且对于6-氮杂-UMP和6-氰基-UMP,抑制常数(Ki)被确定为分别为12.4μM和29μM。发现6-氨基-UMP是ODCase的有效抑制剂之一,其抑制常