Oxidative phosphorylation coupled to electron transfer in the filarial parasite Setaria digitata.

The filarial parasite of Bos indicus, Setaria digitata is reported to have many unique characteristics such as cyanide insensitivity and mitochondrial hydrogen peroxide production. The latter is more sensitive to the alternative oxidase inhibitor salicylhydroxamic acid (SHAM). Studies on the generation of ATP molecules through mitochondriae in the presence of different substrates and inhibitors showed that the oxidative phosphorylation coupled to electron transport occurs mainly at site I and involves the participation of quinone Q8. Based on the data, a scheme for the filarial electron transport system is proposed in which the quinones have a central role. Hence inhibitors at the quinone level might prove to be effective targets for chemotherapy.