A PERMSELECTIVE-MEMBRANE ELECTRODE FOR THE ELECTROCHEMICAL STUDY OF REDOX PROTEINS - APPLICATION TO CYTOCHROME C(552) FROM THIOBACILLUS-FERROOXIDANS

A simple and effective procedure for electrode construction, based on casting a permselective membrane onto a gold electrode surface is desc ribed. A redox protein solution is entrapped between the permselective membrane and the electrode surface. The so-mounted permselective-memb rane electrode placed in an electrolyte solution is used to study hors e heart cytochrome c as a test system. The measured formal potential a nd the pH dependence profile are in accordance with the literature dat a. The permselective-membrane electrode is also used to investigate th e electrochemistry of cytochrome C-552 from Thiobacillus ferrooxidans and the pH dependence of its formal potential. The performance of this electrode makes it very attractive for studying redox proteins presen t in limited amounts only.