PH-dependent structures of the manganese binding sites in oxalate decarboxylase as revealed by high-field electron paramagnetic resonance.

ABSTRACT: A high-field electron paramagnetic resonance (HFEPR) study of oxalate decarboxylase (OxdC) is reported. OxdC breaks down oxalate to carbon dioxide and formate and possesses two distinct manganese(II) binding sites, referred to as site-1 and -2. The Mn(II) zero-field interaction was used to probe the electronic state of the metal ion and to examine chemical/mechanistic roles of each of the Mn(II) centers. High magnetic-fields were exploited not only to resolve the two sites, but also to measure accurately the Mn(II) zero-field parameters of each of the sites. The spectra exhibited surprisingly complex behavior as a function of pH. Six different species were identified based on their zero-field interactions, two corresponding to site-1 and four states to site-2. The assignments were verified

SUBMITTER: Tabares LC 

PROVIDER: S-EPMC2752729 | biostudies-literature | 2009 Jul

REPOSITORIES: biostudies-literature