Measurement of the oxidation‐reduction potentials of amicyanin and c‐type cytochromes from Paracoccus denitrificans

摘要

>The oxidation-reduction potentials of four periplasmic electron carrier proteins from Paracoccus denitrificans have been determined. Their midpoint potentials are: amicyanin, 294±6 mV; cytochrome c-550, 253±5 mV; cytochrome c-551i, 190±4 mV, and cytochrome c-553i, 148±5 mV. Although rapid amicyanin-mediated transfer of electrons from methylamine dehydrogenase to cytochrome c-551i was observed, reduced amicyanin did not reduce oxidized cytochrome c-551i in the absence of methylamine dehydrogenase.