作者:Drazen Ostovic、Roger M. G. Roberts、Maurice M. Kreevoy
DOI:10.1021/ja00364a026
日期:1983.12
Primary kinetic hydrogen isotope effects (KIE's) for hydride transfer between NAD/sup +/ analogues have been measured for reactions with equilibrium constants ranging from 0.7 to 10/sup 16/. There is no sign of the sharp change in KIE which would signal the change of a rate limiting step in a multistep mechanism, and other evidence also indicates a one-step mechanism. The secondary KIE produced by
对于平衡常数范围为 0.7 到 10/sup 16/ 的反应,已经测量了 NAD/sup +/ 类似物之间氢化物转移的主要动力学氢同位素效应 (KIE)。没有迹象表明 KIE 的急剧变化表明多步机制中速率限制步骤的变化,其他证据也表明了单步机制。当转移原子为 D 时,通过将受体位点上已连接的氢从 H 变为 D 产生的次级 KIE 比转移原子为 H 时小 10%。这些结果与初级 KIE 的值相结合,强烈表明某些反应坐标中的核隧穿。