A possible role for the covalent heme-protein linkage in cytochrome c revealed via comparison of N-Acetylmicroperoxidase-8 and a synthetic, monohistidine-coordinated heme peptide

N-Acetylmicroperoxidase-8 contains heme and residues 14-21 of horse mitochondrial cytochrome c(cyt c). The two thioether bonds linking protein to heme in cyt c are present in N-Acetylmicroperoxidase-8, and the native axial ligand His-18 remains coordinated to iron.