@article{el kasmi_leopold_galligan_robertson_saavedra_el kacemi_bowden_2002, title={Adsorptive immobilization of cytochrome c on indium/tin oxide (ITO): electrochemical evidence for electron transfer-induced conformational changes}, volume={4}, ISSN={["1388-2481"]}, DOI={10.1016/S1388-2481(01)00299-5}, abstractNote={The adsorptive immobilization and electrochemistry of horse and yeast cytochrome c on indium/tin oxide (ITO) electrodes is reported. Near-monolayer coverage was achieved in pH 7 phosphate buffers of ionic strength equal to 10 and 50 mM, respectively, for the horse and yeast species. The layers exhibit very well-behaved voltammetry and are stable on the timescale of hours to days. Cyclic voltammetry revealed quasireversible behavior that is a product of both electron transfer (ET) kinetics and ET-induced conformational changes. A square scheme mechanism linking the redox states and the conformational states is proposed. Using a simple ET kinetic model that adequately describes the voltammetry at higher scan rates, a standard ET rate constant of 18s−1 was determined for adsorbed horse cytochrome c. With decreasing scan rate, we observed a limiting peak separation of approximately 10 mV, an example of unusual quasireversibility (UQR) that we attribute to the effect of conformational changes. Finally we note that the intrinsic cytochrome c ET rate on ITO is some 6 orders of magnitude less than for gold.}, number={2}, journal={ELECTROCHEMISTRY COMMUNICATIONS}, author={El Kasmi, A and Leopold, MC and Galligan, R and Robertson, RT and Saavedra, SS and El Kacemi, K and Bowden, EF}, year={2002}, month={Feb}, pages={177–181} }