DFT analysis of co-alkyl and co-adenosyl vibrational modes in B12-cofactors.

Article Details

Citation

Kozlowski PM, Andruniow T, Jarzecki AA, Zgierski MZ, Spiro TG

DFT analysis of co-alkyl and co-adenosyl vibrational modes in B12-cofactors.

Inorg Chem. 2006 Jul 10;45(14):5585-90.

PubMed ID
16813422 [ View in PubMed
]
Abstract

Density functional theory (DFT)-based normal mode calculations have been carried out on models for B12-cofactors to assign reported isotope-edited resonance Raman spectra, which isolate vibrations of the organo-Co group. Interpretation is straightforward for alkyl-Co derivatives, which display prominent Co-C stretching vibrational bands. DFT correctly reproduces Co-C distances and frequencies for the methyl and ethyl derivatives. However, spectra are complex for adenosyl derivatives, due to mixing of Co-C stretching with a ribose deformation coordinate and to activation of modes involving Co-C-C bending and Co-adenosyl torsion. Despite this complexity, the computed spectra provide a satisfactory re-assignment of the experimental data. Reported trends in adenosyl-cobalamin spectra upon binding to the methylmalonyl CoA mutase enzyme, as well as on subsequent binding of substrates and inhibitors, provide support for an activation mechanism involving substrate-induced deformation of the adenosyl ligand.

DrugBank Data that Cites this Article

Drug Targets
DrugTargetKindOrganismPharmacological ActionActions
CyanocobalaminMethylmalonyl-CoA mutase, mitochondrialProteinHumans
Yes
Cofactor
Details