HYDROGEN BONDS IN CATALYST TRIAD OF SERINE PROTEASES

SIR提供D，L-[15 N2-咪唑基]组氨酸; 1.48g Cleland和 克里沃伊最近提出了一种特殊类型的氢 一种称为低势垒氢键（LBHB）的氢键（H-键）可以解释 对于“缺失”的过渡态稳定性， 许多酶的催化能力，Frey等人提出， 天冬氨酸102和组氨酸57之间的氢键在催化 丝氨酸蛋白酶三联体是催化重要的 LBHB。 使用由SIR和NMR提供的“N”标记的组氨酸 光谱，我们已经表明，天冬氨酸-组氨酸和顺式 urocanic氢键，这是不符合基本原则的 LBHB假说。 理论和实验之间的矛盾 这些范式系统令人怀疑目前是否存在 在酶活性位点内定义。

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.