Influence of anion flux upon mitochondrial oxidative phosphorylation

We have measured mitochondrial ATP synthesis during passive anion influx and find that influx of phosphate leads to diminished efficiency (as reflected in the ATP:0 ratio) whereas influx of acetate produced enhanced efficiency. The anions, sulfate, propionate, and thiocyanate, are without influence on the ATP:0 ratio. It is likely that the opposite effects of phosphate and acetate on the ATP:0 ratio reflect phosphate-acetate exchange, and that acetate influx produces its positive effect on ATP synthesis by promoting phosphate efflux. Thus, phosphate efflux may be associated with increased, and phosphate influx, with decreased energy conservation.