Enzymatic reaction sequences as coupled multiple traces on a multidimensional landscape.
Enzymatic reaction sequences as coupled multiple traces on a multidimensional landscape.
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DOI：
10.1016/j.tibs.2007.12.001
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发表时间：
2008-03
影响因子：
13.8
通讯作者：
L. Swint-Kruse;H. F. Fisher
中科院分区：
文献类型：
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作者：
L. Swint-Kruse;H. F. Fisher
我们认为，酶催化反应最好通过大的三维势能表面来描述，该势能表面由一维酶构象异构体的数量定义，第二个是反应步骤数，第三个是吉布斯自由能。除了适应不符合当前机械范式的实验观察之外，这样的表面还能够实现多个交叉反应途径、途径漏斗、配体结合能量转导以及替代反应途径之间的动力学耦合。这种景观还赋予酶灵活性，使酶能够为可能发生的任何反应条件寻找最佳途径。因此，耦合途径使得实验条件中相对较小的差异能够导致观察到的反应行为的突然现象学变化。
We propose that an enzyme-catalyzed reaction is best described by a large, three-dimensional potential energy surface, defined by the number of enzyme conformers in one dimension, the number of reaction steps as the second and Gibbs free energy as the third. Aside from accommodating experimental observations that do not fit current mechanistic paradigms, such a surface enables multiple intersecting reaction pathways, pathway funneling, ligand binding energy transduction and kinetic coupling between alternative reaction pathways. The landscape also confers flexibility, enabling an enzyme to seek out an optimal pathway for any reaction conditions that might occur. Thus, coupled pathways enable relatively minor differences in experimental conditions to result in abrupt phenomenological changes in the observed behavior of the reaction.