P. Bianco et J. Haladjian, CONTROL OF THE ELECTRON-TRANSFER REACTIONS BETWEEN C-TYPE CYTOCHROMESAND LIPID-MODIFIED ELECTRODES, Electrochimica acta, 39(7), 1994, pp. 911-916
The electron transfer reactions between a lipid-modified pyrolytic gra
phite (PG) electrode and four c-type cytochromes (monoheme cytochrome
c and cytochrome c553 from Desulfovibrio vulgaris Hildenborough, tetra
heme cytochromes c3 from D. vulgaris Hildenborough and D. desulfurican
s Norway) have been studied by cyclic and square-wave voltammetry. No
signal was detected at the PG electrode simply coated with a mixed lay
er of phosphatidylcholine (PC) and cholesterol (CH). The peaks corresp
onding to the reduction-reoxidation of cytochrome C553 were restored b
y doping the lipid layer with laurate anions (LA). In the case of cyto
chrome c, a rapid electron transfer reaction has been observed at the
(PC-CH + LA)-modified PG electrode, accompanied by the progressive inc
orporation of protein molecules. By studying the effect of pH on the c
v peak heights, it has been shown that the profiles for the four cytoc
hromes depend on the protonation of the laurate anions and the protona
tion-deprotonation of protein species. The results support the electro
static nature of the interactions between the cytochrome and the lipid
layer but other factors (eg hydrophobic effects) are not excluded.