Electrochemical reactions of horse heart cytochrome c at graphite electrodes.
The interaction of cytochrome c with a paraffin-wax-impregnated spectroscopic graphite electrode (WISGE) was studied in a medium consisting of 0.1 M potassium phosphate, pH 7.0, by means of differential pulse and cyclic voltammetry. Ferricytochrome c yields on voltammograms a single cathodic peak C around a potential of -0.3 V (vs. Ag/AgCl) and two anodic peaks AI and AII around the potentials of 0.66 and 0.89 V, respectively. Cathodic peak C corresponds to a catalytic reaction during which ferricytochrome c is reduced to ferrocytochrome c: ferricytochrome c is then regenerated by chemical oxidation of ferrocytochrome c by oxygen adsorbed at the WISGE surface. The first, more negative anodic peak AI corresponds to anodic electrochemical oxidation of tyrosine residues, whereas the second, more positive anodic peak (peak AII) corresponds to an anodic reaction of haemin. Voltammetry at a WISGE may provide a valuable technique for obtaining data about cytochrome c properties on electrically charged surface.
D000818:Animals; D003574:Cytochrome c Group / Q000378:metabolism*; D004563:Electrochemistry; D004566:Electrodes; D006108:Graphite; D006736:Horses; D007700:Kinetics; D009206:Myocardium / Q000378:metabolism*; D011199:Potentiometry; D011506:Proteins / Q000378:metabolism
D003574:Cytochrome c Group; D011506:Proteins; D006108:Graphite