The hard-soft acid-base principle in enzymatic catalysis: dual reactivity of phosphoenolpyruvate.
The hard-soft acid-base principle in enzymatic catalysis: dual reactivity of phosphoenolpyruvate.
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DOI：
10.1073/pnas.93.10.4612
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发表时间：
1996-05
影响因子：
11.1
通讯作者：
Y. Li;J. N. Evans
中科院分区：
文献类型：
--
作者：
Y. Li;J. N. Evans
本文利用量子化学计算量化的密度泛函理论分析了磷酸烯醇丙酮酸（PEP）C3 的化学反应性。 PEP 参与许多重要的酶促反应，其中 C3 原子的行为类似于碱基。在此分析的三种不同的酶反应中，根据硬-软酸碱原理，C3 有时表现得像软碱，有时表现得像硬碱。人们发现PEP C3 的这种双重性质与分子的构象变化有关。这导致了一个可检验的假设：PEP 在不同使用 PEP 的酶的酶-底物复合物中采用特定的构象，并且酶通过控制羧酸根和 PEP 的 C==C 双键之间的二面角来控制反应性。
In this paper, the chemical reactivity of C3 of phosphoenolpyruvate (PEP) has been analyzed in terms of density functional theory quantified through quantum chemistry calculations. PEP is involved in a number of important enzymatic reactions, in which its C3 atom behaves like a base. In three different enzymatic reactions analyzed here, C3 sometimes behaves like a soft base and sometimes behaves like a hard base in terms of the hard-soft acid-base principle. This dual nature of C3 of PEP was found to be related to the conformational change of the molecule. This leads to a testable hypothesis: that PEP adopts particular conformations in the enzyme-substrate complexes of different PEP-using enzymes, and that the enzymes control the reactivity through controlling the dihedral angle between the carboxylate and the C==C double bond of PEP.