Effect of the bacterial DNA gyrase inhibitors, novobiocin, nalidixic acid, and oxolinic acid, on oxidative phosphorylation.
Gallagher M, Weinberg R, Simpson MV
Journal of Biological Chemistry (1986)
Category: mitochondria, mitochondrial DNA, topoisomerase ¤ Added: Oct 15, 2007 ¤ Rating: ◊◊
When incubated with isolated intact rat liver mitochondria, novobiocin and nalidixic acid act as uncouplers of oxidative phosphorylation; they stimulate oxygen uptake and inhibit ATP synthesis. Novobiocin is about as powerful an uncoupler as is 2,4-dinitrophenol, nalidixic acid is somewhat less powerful, and oxolinic acid exerts no inhibition whatsoever at the concentrations used. The three inhibitors are without effect on oxidative phosphorylation in Escherichia coli nor does novobiocin affect this process in a novobiocin-permeable mutant of yeast. While it would appear that oxolinic acid may be a relatively specific tool for the manipulation of the superhelicity of DNA in complex systems such as mammalian mitochondria and intact mammalian cells, the specificity of each of these inhibitors may depend upon the particular conditions and species used and such experiments require adequate controls on oxidative phosphorylation.