G. Izzo, F. Guerrieri, S. Papa
Sep 15, 1978
Citations
1
Influential Citations
24
Citations
Quality indicators
Journal
FEBS Letters
Abstract
~kyl-hydroxyqu~oline-~-oxide inhibits, like ~tirnyc~ A, electron flow in the mitochond~~ respiratory chain between b and cl cytochromes [l-3] . Although these two inhibitors are widely used their mechanism of action is not yet fully understood [2,3]. It has been proposed that alkyl-hydroxyqu~oline-~-oxide and antimycin share the same reaction site [2-61. The concentration in the inner mitochondrial membrane of specific binding sites for 2-heptyl-4-hydroxyquinoline&oxide (HQNO) is identical with that of antimycin binding sites, antimycin antagonizes the binding of HQNO and the ~bition of forward electron flow by HQNO is apparently additive with that by antimycin [6] . Both inhibitors induce a characteristic oxidant-dependent reduction of b cytochromes [3-81. In this paper a kinetic analysis of the effect of HQNO and antimycin on the aerobic oxidation and reduction of b cytochromes is reported. The results provide evidence for difference in the reaction sites of the two inhibitors.