Gossypol Inhibits Electron Transport and Stimulates ROS Generation in Yarrowia lipolytica Mitochondria

This work studied the effect of gossypol on the mitochondrial respiratory chain of Yarrowia lipolytica. The compound was shown to inhibit mitochondrial electron transfer and stimulate generation of reactive oxygen species. The inhibition kinetics in oxidation of various substrates (NADH, succinate, α-glycerophosphate and pyruvate + malate) by isolated mitochondria was investigated. Analysis of the kinetic parameters showed gossypol to inhibit two fragments of the mitochondrial electron transfer chain: a) between coenzyme Q and cytochrome b with K(IIIi) of 118.3 μM (inhibition by the noncompetitive type), and b) at the level of exogenous NADH dehydrogenase with of K(Ii) 17.2 μM (inhibition by the mixed type).