Chlorpromazine inhibition of electron transport in Azotobacter vinelandii membranes.

Chlorpromazine was a potent inhibitor of O2-dependent malate oxidation, but not of H2 oxidation in Azotobacter vinelandii membranes. However, chlorpromazine did not significantly affect the activity of malate reductase or the reduction of cytochromes c and d. In the presence of chlorpromazine, cytochrome o failed to form a complex with CO. The site of action of chlorpromazine seems to be in the cytochromes c to cytochrome o branch, the pathway utilized by malate, succinate and NADH, but not by H2.