title: Electrochemical analysis of the effect of Ca2+ on cardiolipin-cytochrome c interaction.
abstract: Mitochondrial Ca2+ has been considered a trigger for the release of cytochrome c, which is a critical and early event in the induction of cell apoptosis, although the molecular mechanism underlying this effect is still not fully understood. Here we investigate the interaction between cytochrome c and cardiolipin and the effect of Ca2+ on this interaction using electrochemical methods. Experimental results revealed that modification of cardiolipin onto the surface of a pyrolytic graphite electrode could lead to a rapid direct electron transfer of cytochrome c through the electrostatic interaction between the protein and the cardiolipin. Addition of Ca2+ to the test solution containing cytochrome c could cause the decrease of the redox peaks of the protein, and the peaks could be recovered when Ca2+ was chelated by ethylenediaminetetraacetate. The cardiolipin-cytochrome c interaction and the Ca2+ effect were also investigated with the variation of the charges of lipids, buffer solutions, reaction time, and valencies of cations for comparison.
authors.affiliation: Department of Biochemistry and National Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing, PR China.
authors.forename: Yinxi
authors.initials: Y
authors.lastname: Huang
authors.forename: Lei
authors.initials: L
authors.lastname: Liu
authors.forename: Chang
authors.initials: C
authors.lastname: Shi
authors.forename: Junyi
authors.initials: J
authors.lastname: Huang
authors.forename: Genxi
authors.initials: G
authors.lastname: Li
mesh_terms: D000818:Animals; D002118:Calcium / Q000737:chemistry / Q000378:metabolism*; D002308:Cardiolipins / Q000378:metabolism*; D002417:Cattle; D045304:Cytochromes c / Q000378:metabolism*; D004563:Electrochemistry; D006736:Horses; D008928:Mitochondria / Q000201:enzymology / Q000378:metabolism; D011485:Protein Binding
chemical_list: D002308:Cardiolipins; D045304:Cytochromes c; D002118:Calcium