Purification and preliminary characterization of three c-type cytochromes from pseudomonas nautica strain 617

Three c-type cytochromes, namely cytochrome c_553’ cytochrome c_553(548) and Cytochrome c’, were purified from the marine denitrifying bacterium Pseudomonos nautica strain 617. These three monohemic cytochromes present in small amounts were preliminarily characterized by physico-chemical and spectroscopic techniques. The visible and the ¹H-NMR spectra show that cytochrome c₅₅₃ and cytochrome c_553(548) have histidine-methionine as iron axial ligands. Cytochrome c₅₅₃ and cytochrome c_553(548) have mid-paint redox potentials of +269 mV and +223 mV, at pH 7.6, and their molecular masses are 14 kDa and 17 kDa, respectively. Cytochrome c’ has a molecular mass of 21 kDa and its visible spectrum is typical of a high spin heme.