Control of oxidative phosphorylation in AS-30D hepatoma mitochondria.

1. The distribution of control of the rate of state 3 respiration of AS-30D hepatoma mitochondria was determined. 2. The ATP/ADP carrier (flux control coefficient, Ci = 0.70) and the ATP synthase (Ci = 0.19-0.32) were the only steps that exerted significant control on the phosphorylating flux supported by either glutamate+malate, pyruvate+malate, or succinate+rotenone. This is in contrast to liver mitochondria where the control is distributed between several steps. 3. It is suggested that this pattern of control of phosphorylation in hepatoma mitochondria is a consequence of a lower content of adenine nucleotides or a higher content of Mg2+.