Mechanistic study of manganese-substituted glycerol dehydrogenase using a kinetic and thermodynamic analysis.
Mechanistic study of manganese-substituted glycerol dehydrogenase using a kinetic and thermodynamic analysis.
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利用动力学和热力学分析研究锰取代的甘油脱氢酶的机理
DOI：
10.1371/journal.pone.0099162
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发表时间：
2014
期刊：
影响因子：
3.7
通讯作者：
Wang S
中科院分区：
文献类型：
--
作者：
Fang B;Niu J;Ren H;Guo Y;Wang S
采用动力学和热力学分析的简单方法，研究了金属离子取代提高脱氢酶活性的机理。通过对底物和产物结合能的分析，揭示了金属离子在催化增强中的作用。来自肺炎克雷伯氏菌的甘油脱氢酶（GDH），其证明了通过用锰离子取代锌离子而提高了活性，用作金属离子取代的机理研究的模型。考虑到二羟基丙酮（DHA）的非竞争性产物抑制和NADH的竞争性产物抑制，提出了一个基于有序Bi-Bi机理的动力学模型.通过获得底物和产物抑制的初步动力学参数，估计的参数的数量从10个减少到4个非线性回归为基础的动力学参数估计。时间-浓度曲线的模拟值与实验值吻合较好，Mn-GDH和GDH的平均相对误差分别为11.5%和12.7%。由动力学参数得到的Mn-GDH和GDH的酶三元复合物结合能的比较表明，金属离子取代促进了二氧丙酮的释放。阐述了金属离子在催化剂强化中的作用。
Mechanistic insights regarding the activity enhancement of dehydrogenase by metal ion substitution were investigated by a simple method using a kinetic and thermodynamic analysis. By profiling the binding energy of both the substrate and product, the metal ion's role in catalysis enhancement was revealed. Glycerol dehydrogenase (GDH) from Klebsiella pneumoniae sp., which demonstrated an improvement in activity by the substitution of a zinc ion with a manganese ion, was used as a model for the mechanistic study of metal ion substitution. A kinetic model based on an ordered Bi-Bi mechanism was proposed considering the noncompetitive product inhibition of dihydroxyacetone (DHA) and the competitive product inhibition of NADH. By obtaining preliminary kinetic parameters of substrate and product inhibition, the number of estimated parameters was reduced from 10 to 4 for a nonlinear regression-based kinetic parameter estimation. The simulated values of time-concentration curves fit the experimental values well, with an average relative error of 11.5% and 12.7% for Mn-GDH and GDH, respectively. A comparison of the binding energy of enzyme ternary complex for Mn-GDH and GDH derived from kinetic parameters indicated that metal ion substitution accelerated the release of dioxyacetone. The metal ion's role in catalysis enhancement was explicated.
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影响因子：
3
作者：
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通讯作者：
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影响因子：
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