Effect of mercurials on NADH oxidation and energy-linked hydrogen ion gradient in submitochondrial particles

Abstract

Earlier work has shown that the sensitivity of NADH oxidation in submitochondrial particles to inhibition by mercurial increases, if the particles are ‘preconditioned’ by allowing them to oxidize a small amount of NADH before exposure to the inhibitor. This inhibition is relieved by the addition of ethylenediamine tetraacetate (EDTA). The effect of EDTA and mersalyl on the decolorization of membrane-bound bromthymol blue, when it is energized by NADH oxidation, has been measured. Under conditions where EDTA overcame the inhibition of oxidation by mersalyl, it did not affect the bromthymol blue response. The involvement of an -SH in the energy-driven establishment of a proton gradient thus becomes apparent.