Temperature dependence of the mitochondrial inner membrane anion channel. The relationship between temperature and inhibition by protons.

In this paper, we investigate the temperature and pH dependence of the mitochondrial inner membrane anion channel (IMAC) that is believed to be involved in mitochondrial volume homeostasis. At pH 7. 4, the flux of malonate is highly temperature-dependent with rates increasing from 1 nmol/min mg at 5 degrees C to 1900 nmol/min mg at 45 degrees C.

The mitochondrial inner membrane anion channel is inhibited by DIDS.

The mitochondrial inner membrane anion channel (IMAC) is a channel, identified by flux studies in intact mitochondria, which has a broad anion selectivity and is maintained closed or inactive by matrix Mg2+ and H+. We now present evidence that this channel, like many other chloride/anion channels, is reversibly blocked/inhibited by stilbene-2,2'-disulfonates. Inhibition of malonate transport approaches 100% with IC50 values of 26, 44, and 88 mu M for DIDS, H2-DIDS, and SITS respectively and Hill coefficients < or = 1.