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Reaction Mechanism of Molybdoenzyme Formate Dehydrogenase
Author(s) -
Leopoldini Monica,
Chiodo Sandro G.,
Toscano Marirosa,
Russo Nino
Publication year - 2008
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200800906
Subject(s) - formate , formate dehydrogenase , chemistry , catalysis , density functional theory , active site , molybdenum , residue (chemistry) , inorganic chemistry , computational chemistry , organic chemistry
Formate dehydrogenase is a molybdoenzyme of the anaerobic formate hydrogen lyase complex of the Escherichia coli microrganism that catalyzes the oxidation of formate to carbon dioxide. The two proposed mechanisms of reaction, which differ in the occurrence of a direct coordination or not of a SeCys residue to the molybdenum metal during catalysis were analyzed at the density functional level in both vacuum and protein environments. Some DF functionals, in addition to the very popular B3LYP one, were employed to compute barrier heights. Results revealed the role played by the SeCys residue in performing the abstraction of the proton from the formate substrate. The computation of the energetic profiles for both mechanisms indicated that the reaction barriers are higher when the selenium is directly coordinated to the metal, whereas less energy is required when SeCys is not a ligand at the molybdenum site.