Resonance Raman Studies on Heme Ligand Stretching Modes in Methionine80-Depleted Cytochrome c: Fe-His, Fe-O₂, and O-O Stretching Modes.

ABSTRACT: The peroxidase activity of cytochrome (cyt) c increases when Met80 dissociates from the heme iron, which is related to the initial cyt c membrane permeation step of apoptosis. Met80-dissociated cyt c can form an oxygenated species. Herein, resonance Raman spectra of Met80-depleted horse cyt c (M80A cyt c) were analyzed to elucidate the heme ligand properties of Met80-dissociated cyt c. The Fe-His stretching (ν_Fe-His) mode of ferrous M80A cyt c was observed at 236 cm^-1, and this frequency decreased by 1.5 cm^-1 for the ¹⁵N-labeled protein. The higher ν_Fe-His frequency of M80A cyt c than of other His-ligated heme proteins indicates strong heme coordination and the imidazolate charact

SUBMITTER: Zhang M 

PROVIDER: S-EPMC10041640 | biostudies-literature | 2023 Mar

REPOSITORIES: biostudies-literature