A low-barrier hydrogen bond in the catalytic triad of serine proteases? Theory versus experiment
A low-barrier hydrogen bond in the catalytic triad of serine proteases? Theory versus experiment
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DOI：
10.1126/science.278.5340.1128
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发表时间：
1997-11-07
期刊：
影响因子：
56.9
通讯作者：
Bachovchin, WW
中科院分区：
文献类型：
--
作者：
Ash, EL;Sudmeier, JL;Bachovchin, WW
Cleland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），可能解释了许多酶催化能力背后的“缺失”过渡态稳定，Frey等人提出，丝氨酸蛋白酶催化三联体中天门氨酸102和组氨酸57之间的氢键是催化重要的LBHB的一个例子。这里考虑了与LBHB假说的基本原则不一致的天冬氨酸-组氨酸和顺式-尿嘧啶氢键的实验事实。在这些范例系统中，理论和实验之间的不一致性使人们对酶活性位点内LBHBs的存在产生了怀疑。
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 ef 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. Experimental facts are here considered regarding 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 LBHBs, as currently defined, within enzyme active sites.