Electronic and structural properties of Cob(I)alamin: Ramifications for B₁₂-dependent processes

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• 作者：Manoj Kumar^a ; ^b ; Pawel M. Kozlowski^a ; ^c ; ^{pawel@louisville.edu}
• 关键词：CNCbl ; cyanocobalamin ; AdoCbl ; adenosylcobalamin ; MeCbl ; methylcobalamin ; CoIIICbl ; cob(III)alamin ; CoIICbl ; cob(II)alamin ; CoICbl ; cob(I)alamin ; MetH ; methionine synthase ; CoFeSP ; corrinoid/Fe-S protein ; MtaBC ; methanol-cobalamin methyltransferase ; Im ; imidazole ; DFT ; density functional theory ; QM/MM ; quantum mechanics/molecular mechanics ; CASSCF ; complete active space self-consistent field ; CASPT2 ; complete active space perturbation theory ; ONIOM ; our own n-layered integrated molecular orbital
• 刊名：Coordination Chemistry Reviews
• 出版年：2017
• 出版时间：15 February 2017
• 年：2017
• 卷：333
• 期：Complete
• 页码：71-81
• 全文大小：2550 K
• 卷排序：333

文摘

The MetH-bound CoI⋯H interaction is the first example of a low spin d8 metal ion-induced hydrogen bond inside any biological complex. The CASSCF/XMCQDPT2 calculations indicate that the presence of the axial base alters the contribution of the CoI(d8) configuration and the CoII(d7)-corrin radical(π∗)1 configuration to the CoICbl ground state wavefunction. The multiple electronic excitations seen in the α/β spectral region of vitamin B12 as well as MeCbl implies that the vibrational progression of a corrin π → π∗ band cannot be considered as a genuine spectroscopic signature in the photospectra of low-energy cobalamin. The CoI⋯H interaction tunes the reduction potential of the CoII/CoI process that may make it accessible inside methyltransferases.