Synthesis of Second-Generation Transition State Analogues of Human Purine Nucleoside Phosphorylase
作者:Gary B. Evans、Richard H. Furneaux、Andrzej Lewandowicz、Vern L. Schramm、Peter C. Tyler
DOI:10.1021/jm030305z
日期:2003.11.1
Immucillin-G have been shown previously to be potent inhibitors of PNP. We now report the synthesis of a second generation of stable transition state analogues, DADMe-Immucillins 2, 3, and 4, with increased distance between ribooxacarbenium and purine mimics by incorporation of a methylene bridge between these groups. These compounds are potent inhibitors with equilibrium dissociation constants as low
嘌呤核苷磷酸化酶(PNP)通过固定核嘌呤和磷酸亲核试剂之间的阳离子核糖氧碳鎓碳的迁移催化亲核置换反应。随着磷解反应沿着反应坐标进行,嘌呤和碳正离子之间的距离增加,而碳正离子和磷酸根阴离子之间的距离减小。以前已显示Immucillin-H和Immucillin-G是PNP的有效抑制剂。现在,我们报告了第二代稳定的过渡态类似物DADMe-Immucillins 2、3和4的合成,其中通过在这些基团之间引入亚甲基桥,增加了核糖氧碳鎓与嘌呤模拟物之间的距离。这些化合物是有效的抑制剂,对人PNP的平衡解离常数低至7 pM。酶促过渡态的稳定化学类似物必然是不完善的,因为它们缺乏过渡态的部分键特征。Immucillins和DADMe-Immucillins从过渡态的产物和反应方面代表方法。