Spectroscopic and computational characterization of the NO adduct of substrate-bound Fe(II) cysteine dioxygenase: insights into the mechanism of O2 activation.

ABSTRACT: Cysteine dioxygenase (CDO) is a mononuclear nonheme iron(II)-dependent enzyme critical for maintaining appropriate cysteine (Cys) and taurine levels in eukaryotic systems. Because CDO possesses both an unusual 3-His facial ligation sphere to the iron center and a rare Cys-Tyr cross-link near the active site, the mechanism by which it converts Cys and molecular oxygen to cysteine sulfinic acid is of broad interest. However, as of yet, direct experimental support for any of the proposed mechanisms is still lacking. In this study, we have used NO as a substrate analogue for O2 to prepare a species that mimics the geometric and electronic structures of an early reaction intermediate. The resultant unusual S = (1)/2 {FeNO}(7) species was characterized by magnetic circular dichroism, electron pa

SUBMITTER: Blaesi EJ 

PROVIDER: S-EPMC3974268 | biostudies-literature | 2013 Sep

REPOSITORIES: biostudies-literature