Catalytic role of enzymes: Short strong H-bond-induced partial proton shuttles and charge redistributions
Catalytic role of enzymes: Short strong H-bond-induced partial proton shuttles and charge redistributions
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DOI：
10.1073/pnas.97.12.6373
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发表时间：
2000-06-06
影响因子：
11.1
通讯作者：
Lee, JY
中科院分区：
文献类型：
--
作者：
Kim, KS;Oh, KS;Lee, JY
一个两步反应机制（催化的酸和碱交替）与部分质子穿梭和电荷重新分配促进短强H键（SSHB）（发挥双重作用，作为一个两酸/碱催化剂），提出了解释在酶促反应中观察到的巨大的速率增强涉及碳负离子中间体。在两步反应中，SSHB的存在增强了酶与底物的相互作用，有利于反应物的过渡态结构。对甾酮异构酶的量子理论研究为SSHB在酶活性中的辅助作用提供了证据。对两步反应机理的理解将有助于设计新的功能酶和抗体酶。
A two-step reaction mechanism (catalyzed alternatively by acid and base) with partial proton shuttles and charge redistributions promoted by short strong H bonds (SSHBs) (playing a dual role as an amphi-acid/base catalyst) is proposed to explain the enormous rate enhancement observed in enzymatic reactions involving carbanion intermediates. The SSHBs in the two-step reactions are found to be responsible for enhancing enzyme-substrate interactions in favor of the transition state structure over that of reactant, The detailed quantum theoretical studies of ketosteroid isomerase provide evidence of assisting roles of SSHB in enzymatic activity. The understanding of the two-step reaction mechanism would be a useful aid in designing novel functional enzymes and abzymes.