Transition State Structure for the Hydrolysis of NAD<sup>+</sup> Catalyzed by Diphtheria Toxin
作者:Paul J. Berti、Steven R. Blanke、Vern L. Schramm
DOI:10.1021/ja971317a
日期:1997.12.17
slow hydrolysis of NAD(+) to ADP-ribose and nicotinamide, a reaction that can be exploited to measure kinetic isotope effects (KIEs) of isotopically labeled NAD(+)s. Competitive KIEs were measured by the radiolabel method for NAD(+) molecules labeled at the following positions: 1-(15)N = 1.030 ± 0.004, 1'-(14)C = 1.034 ± 0.004, (1-(15)N,1'-(14)C) = 1.062 ± 0.010, 1'-(3)H = 1.200 ± 0.005, 2'-(3)H = 1
白喉毒素 (DTA) 使用 NAD(+) 作为 ADP-核糖供体来催化真核延伸因子 2 的 ADP-核糖基化。这会抑制蛋白质生物合成并最终导致细胞死亡。在没有生理受体的情况下,DTA 催化 NAD(+) 缓慢水解为 ADP-核糖和烟酰胺,该反应可用于测量同位素标记的 NAD(+) 的动力学同位素效应 (KIE)。竞争性 KIEs 是通过放射性标记方法测量的 NAD(+) 分子标记在以下位置: 1-(15)N = 1.030 ± 0.004, 1'-(14)C = 1.034 ± 0.004, (1-(15)N ,1'-(14)C) = 1.062 ± 0.010, 1'-(3)H = 1.200 ± 0.005, 2'-(3)H = 1.142 ± 0.005, 4'-(3)H = 0.990 ± 0.002, 5'-(3)H = 1.032 ± 0.004, 4'-(18)O = 0.986