Comparative resonance Raman study of cytochrome c oxidase from beef heart and Paracoccus denitrificans

Well-resolved, Soret band excited resonance Raman spectra were measured from the fully oxidized and fully reduced cytochrome c oxidase from beef heart and Paracoccus denitrificans. The vibrational patterns in the marker band region (1450-1700 cm -1 ) were analyzed, and a complete assignment of heme a and heme a 3 vibrational modes is presented, permitting a detailed structural comparison of the mammalian and bacterial enzymes. Similar frequencies of the porphyrin modes for the reduced heme a and the reduced and oxidized heme a 3 are found, indicating a close relationship of the ground-state conformations in all oxidase species studied