Theory of electrophoresis of reacting systems as applied to the sulfhydryl oxidation of creatine kinase.

In an attempt to explain the unusual electrophoretic behavior of fish muscle creatine kinase, a phenomenological theory of transport of reacting systems has been formulated for the electrophoresis of a sulfhydryl protein undergoing oxidation in the presence of a gradient of molecular oxygen. The model assumes slow O2-oxidation of sulfhydryl groups followed by rather rapidly reversible sulfhydryl-disulfide interchange with concomitant change in the electrophoretic mobility of the protein. The computed electrophoretic patterns for this model exhibit a sharp, unimodal ascending boundary but a bimodal descending boundary in which the proportions of the two peaks are time dependent. There is a striking similarity between the theoretical patterns and their experimental counterparts (M.D. Doherty, D.A. Bergman, V.M. Re-Miller, and D.J. Winzor, 1980, Arch. Biochem. Biophys. 202, 558-564); and hence support for consideration of the electrophoresis of fish muscle creatine kinase in these terms.