Identification of heme propionate vibrational modes in the resonance Raman spectra of cytochrome c oxidase.
The propionate groups of heme a and a(3) in cytochrome c oxidase (CcO) have been postulated to mediate both the electron and proton transfer within the enzyme. To establish structural markers for the propionate groups, their associated vibrational modes were identified in the resonance Raman spectra of CcO from bovine (bCcO) and Rhodobacter sphaeroides (RsCcO). The distinction between the modes from the propionates of heme a and heme a(3), as well as those from the propionates on the pyrrole rings A and D in each heme, was made on the basis of H2O-D2O isotope substitution experiments combined with wavelength-selective resonance enhancement (for bCcO) or mutagenesis studies (for RsCcO).
Egawa
Tsuyoshi
T
Department of Physiology and Biophysics, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
Lee
Hyun Ju
HJ
Ji
Hong
H
Gennis
Robert B
RB
Yeh
Syun-Ru
SR
Rousseau
Denis L
DL
D000818:Animals; D002417:Cattle; D018360:Crystallography, X-Ray; D003576:Electron Transport Complex IV / Q000737:chemistry*; D006418:Heme / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D011422:Propionates / Q000737:chemistry*; D012242:Rhodobacter sphaeroides / Q000201:enzymology; D013059:Spectrum Analysis, Raman; D014732:Vibration
D011422:Propionates; D006418:Heme; D003576:Electron Transport Complex IV