respectively. The results indicate that the hydroxyl proton of Tyr-120 exchanges faster than a few milliseconds, whereas those of Tyr-30 and Tyr-36 exchange more slowly. The exchange rate of the Tyr-30 hydroxyl proton, k(ex), under these conditions was determined by (13)C NMR exchange spectroscopy (EXSY) to be 9.2 +/- 1.1 s(-1). The Tyr-36 hydroxyl proton, however, exchanges too slowly to be determined by EXSY
我们描述了一种新的核磁共振方法,用于监测蛋白质中
酪氨酸 (Tyr) 残基的羟基的单个氢交换率。该方法利用 (2S,3R)-[beta(2),epsilon(1,2)-(2)H(3);0,alpha,beta,zeta-(13)C(4);(15)N ]-Tyr,zeta-
SAIL Tyr,通过 7-8 Hz (1)H(delta)-(1)H(delta)-() 间接 (1)H-检测有效地检测和分配 Tyr 环的 (13)C(zeta) 信号13)C(zeta) 自旋耦合或通过直接 (13)C(zeta) 观察。溶解在 H(2)O 和 D(2)O 中的 18.2 kDa 蛋白质 EP
PIb 的三个 Tyr 残基的 (13)C(zeta)
化学位移的比较显示,所有三个 (13)C(zeta) D(2)O 中的信号比 H(2)O 中的信号高约 0.13 ppm(在 150.9
MHz 时约为 20