Kinetic studies of the electron exchange reaction between the octaheme cytochrome c3 (Mr 26000) and the hydrogenase from Desulfovibrio desulfuricans Norway.

The octaheme cytochrome c3 (Mr 26000) from Desulfovibrio desulfuricans Norway was studied using cyclic voltammetry at the pyrolytic graphite electrode. The kinetics of reduction of the octaheme cytochrome c3 (Mr 26000) from D. desulfuricans Norway by the Ni-Fe-Se hydrogenase purified from the same organism was investigated by an electrochemical method. From cyclic voltammetry experiments a value of 8.108M-1S-1 was obtained for the second order homogenous rate constant of the electron transfer between the two proteins. Results are compared with similar experiments performed on the electron exchange between the tetrahemic cytochrome c3 (Mr 13000) and hydrogenase.