J. Biol. Chem., Vol. 261, Issue 19, 8604-8607, 07, 1986
Effect of the bacterial DNA gyrase inhibitors, novobiocin, nalidixic acid, and oxolinic acid, on oxidative phosphorylation
M Gallagher, R Weinberg and MV Simpson
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.