Association of ferri- and ferro-cytochrome c with lipid multilayers: a 31P solid-state NMR study.
The 31P nuclear magnetic resonance anisotropies of dispersions of diacylphosphatidic acid and diacylphosphatidylserine were slightly increased in the presence of cytochrome c: no increase was observed with cardiolipin. However, the 31P spin-lattice relaxation times (T1) for all of these lipids were reduced markedly by the protein. As similar effects were observed with ferri-cytochrome c and with the reduced protein, which is diamagnetic, we suggest that the changes in T1 reflect a reduction in the spectral density of fast motions for the lipid headgroups attendant on binding of protein, rather than paramagnetic relaxation of the phosphorus nuclear spin.
D000818:Animals; D003574:Cytochrome c Group / Q000378:metabolism*; D006736:Horses; D007700:Kinetics; D008081:Liposomes; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D009206:Myocardium / Q000378:metabolism; D010084:Oxidation-Reduction; D010758:Phosphorus
D003574:Cytochrome c Group; D008081:Liposomes; D010758:Phosphorus