Kuta Jadwiga, Patchkovskii Seguei, Zgierski Marek Z, Kozlowski Pawel M
Department of Chemistry, University of Louisville, 2320 S. Brook Street, Louisville, Kentucky 40292, USA.
J Comput Chem. 2006 Sep;27(12):1429-37. doi: 10.1002/jcc.20454.
Computational modeling of the enzymatic activity of B12-dependent enzymes requires a detailed understanding of the factors that influence the strength of the Co--C bond and the limits associated with a particular level of theory. To address this issue, a systematic analysis of the electronic and structural properties of coenzyme B12 models has been performed to establish the performance of three different functionals including B3LYP, BP86, and revPBE. In particular the cobalt-carbon bond dissociation energies, axial bond lengths, and selected stretching frequencies have been analyzed in detail. Current analysis shows that widely used B3LYP functional significantly underestimates the strength of the Co--C bond while the nonhybrid BP86 functional produces very consistent results in comparison to experimental data. To explain such different performance of these functionals molecular orbital analysis associated with axial bonds has been performed to show differences in axial bonding provided by hybrid and nonhybrid functionals.
对依赖维生素B12的酶的酶活性进行计算建模，需要详细了解影响钴-碳键强度的因素以及与特定理论水平相关的限制。为了解决这个问题，已对辅酶B12模型的电子和结构性质进行了系统分析，以确定包括B3LYP、BP86和revPBE在内的三种不同泛函的性能。特别详细分析了钴-碳键离解能、轴向键长和选定的伸缩频率。当前分析表明，广泛使用的B3LYP泛函显著低估了钴-碳键的强度，而非杂化的BP86泛函与实验数据相比产生了非常一致的结果。为了解释这些泛函的不同性能，已进行了与轴向键相关的分子轨道分析，以显示杂化和非杂化泛函提供的轴向键合差异。
