Browse by author
Lookup NU author(s): Emeritus Professor Bernard Golding
Full text for this publication is not currently held within this repository. Alternative links are provided below where available.
Ab initio molecular orbital theory is used to investigate several possible mechanisms involving free radical intermediates for the coenzyme- B12-dependent rearrangement catalyzed by methylmalonyl-CoA mutase. Our calculations suggest that an intermolecular pathway in which transient fragmentation of the substrate-derived radical is followed by recombination of the fragments ('fragmentation-recombination') is unlikely, but not out of the question. An alternative intramolecular pathway ('addition-elimination') is found to be energetically more favorable. Protonation of the species involved in this latter pathway is found to further reduce the barrier for rearrangement. Examination of the middle ground between the protonated and unprotonated intramolecular mechanisms reveals a continuous spectrum of behavior and demonstrates the potential importance of partial proton transfer. Support for this proposal is obtained from the X-ray crystal structure of the protein. The stereochemistry of the rearrangement has also been examined and leads to a new proposal consistent with experiment.
Author(s): Smith DM, Golding BT, Radom L
Publication type: Article
Publication status: Published
Journal: Journal of the American Chemical Society
Year: 1999
Volume: 121
Issue: 40
Pages: 9388-9399
Print publication date: 13/10/1999
ISSN (print): 0002-7863
ISSN (electronic):
URL: http://dx.doi.org/10.1021/ja991649a
DOI: 10.1021/ja991649a
Altmetrics provided by Altmetric
