Figure 5.

Effect of mitochondrial carrier inhibitors on the rate of AtUCP1- and AtUCP2-mediated [¹⁴C]aspartate/aspartate exchange. Proteoliposomes were preloaded internally with 10 mm aspartate, and transport was initiated by adding 1 mm [¹⁴C]aspartate. The incubation time was 7 and 20 s for AtUCP1 and AtUCP2, respectively. Thiol reagents and α-cyanocinnamate were added 2 min before the labeled substrate; the other inhibitors were added together with [¹⁴C]aspartate. The final concentrations of the inhibitors were as follows: 10 μm for mercuric chloride (HgCl₂), carboxyatractyloside (CAT), and bongkrekic acid (BKA); 0.1 mm for mersalyl (MER) and p-hydroxymercuribenzoate (pHMB); 0.2 mm for bromcresol purple (BrCP); 1 mm for N-ethylmaleimide (NEM) and α-cyanocinnamate (CCN); 5 mm for butylmalonate (BMA) and phenylsuccinate (PHS); 25 mm for bathophenanthroline (BAT); 30 mm for pyridoxal 5′-phosphate (PLP); and 0.2% for tannic acid (TAN). The extents of inhibition (percentages) for AtUCP1 (black bars) and AtUCP2 (gray bars) from a representative experiment are given. Similar results were obtained in at least three independent experiments.