HYDROGEN BONDS IN CATALYST TRIAD OF SERINE PROTEASES

SIR提供D，L-[15 N-咪唑基]组氨酸、1.48克克利兰和 Kreevoy最近提出了一种特殊类型的氢 键(H键)，称为低势垒氢键(LBHB)，可以解释 的“缺失”过渡态稳定化。 许多酶的催化能力，以及Frey等人。都建议说 天冬氨酸102与组氨酸57之间的氢键 三联体丝氨酸蛋白酶是一个具有重要催化作用的例子 LBHB。利用SIR和核磁共振提供的“N标记组氨酸” 光谱分析表明，天冬氨酸-组氨酸和顺式 与基本原理不一致的尿路氢键 LBHB假说。理论与实验的不一致之处 这些范式系统令人怀疑是否存在，就像目前一样 定义的，在酶活性部位。

The SIR provided D,L-[15 N2-imidazoyl]Histidine; 1.48g Cleland and Kreevoy recently advanced the idea that a special type of hydrogen bond (H-bond), termed a low-barrier hydrogen bond (LBHB), may account for the "missing" transition state stabilization underlying the catalytic power of many enzymes, and Frey et al. have proposed that the H-bond between aspartic acid 102 and histidine 57 in the catalytic triad of serine proteases is an example of a catalytically important LBHB. Using "N labeled histidine provided by the SIR and NMR spectroscopy, we have shown that the aspartic acid-histidine and cis urocanic H-bonds that are inconsistent with fundamental tenets of the LBHB hypothesis. The inconsistencies between theory and experiment in these paradigm systems cast doubt on the existence of , as currently defined, within enzyme active sites.