Electrochemistry of cytochrome c immobilized on cardiolipin-modified electrodes: A probe for protein–lipid interactions

• Published in: Biochimica et biophysica acta Vol. 1830; no. 3; pp. 2798 - 2803
• Main Authors: Perhirin, Antoine, Kraffe, Edouard, Marty, Yanic, Quentel, François, Elies, Philippe, Gloaguen, Frederic
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.03.2013; Elsevier
• Subjects: Analytical chemistry; Biochemistry, Molecular Biology; Biodiversity and Ecology; Carbon - chemistry; Cardiolipin; Cardiolipins - chemistry; Chemical Sciences; Cytochrome c; Cytochromes c - chemistry; Electrochemical Techniques; electrochemistry; Electrodes; Electron transfer; Electron Transport; Environmental Sciences; Fatty acid chain; fatty acids; glassy carbon electrode; Hydrophobic and Hydrophilic Interactions; hydrophobic bonding; Immobilized Proteins - chemistry; ionic strength; Kinetics; Life Sciences; Lipid anchorage; Microscopy, Atomic Force; Osmolar Concentration; Oxidation-Reduction; phosphatidylcholines; Phosphatidylcholines - chemistry; proteins; Surface Properties; Voltammetry; Cytochrome c; Electron transfer; Lipid anchorage; Voltammetry; Cardiolipin; Fatty acid chain
• ISSN: 0304-4165; 0006-3002; 1872-8006
• DOI: 10.1016/j.bbagen.2012.12.009

Electrochemistry of cytochrome c (cyt c) immobilized on a cardiolipin (CL)/phosphatidylcholine (PC) film supported on a glassy carbon electrode was investigated using variable-frequency AC voltammetry. At low ionic strength, we observed two redox-active subpopulations characterized by distinct values of potential (E1/2) and electron transfer rate constant (kET). At high ionic strength, only one subpopulation was detected, consistent with the existence of very stable cyt c–CL adducts, most probably formed by hydrophobic interactions between the protein and the fatty acid (FA) chains carried by CL. This subpopulation exhibits a comparatively high kET value (>300s−1) apparently changing with the structure of the FA chains of CL, i.e. 18:2(n−6) or 14:0. Our study suggests that electrochemistry can be a useful technique for probing protein–lipid interactions, and more particularly the role played by the specific structure of the FA chains of CL on cyt c binding. ► PC/CL supported films were used to study electrochemistry of immobilized cyt c. ► AC voltammetry experiments showed two subpopulations of immobilized cyt c. ► At high ionic strength, only hydrophobically bound cyt c is detected. ► Redox behavior of cyt c depends on the structure of the FA chains carried by CL.