Folding mechanism of reduced Cytochrome c: equilibrium and kinetic properties in the presence of carbon monoxide.

ABSTRACT: Despite close structural similarity, the ferric and ferrous forms of cytochrome c differ greatly in terms of their ligand binding properties, stability, folding, and dynamics. The reduced heme iron binds diatomic ligands such as CO only under destabilizing conditions that promote weakening or disruption of native methionine-iron linkage. This makes CO a useful conformational probe for detecting partially structured states that cannot be observed in the absence of endogenous ligands. Heme absorbance, circular dichroism, and NMR were used to characterize the denaturant-induced unfolding equilibrium of ferrocytochrome c in the presence and in the absence of CO. In addition to the native state (N), which does not bind CO, and the unfolded CO complex (U-CO), a structurally distinct CO-bound for

SUBMITTER: Latypov RF 

PROVIDER: S-EPMC2653224 | biostudies-literature | 2008 Nov

REPOSITORIES: biostudies-literature