Estimation of membrane potential and pH difference across the cristae membrane of rat liver mitochondria.

摘要: The cristae membrane or M phase of resting respiring rat liver mitochondria becomes relatively permeable to K+ ions in presence valinomycin. equilibrium distribution across the can therefore be used estimate potential ΔΨ provided that precautions are taken minimise swelling valinomycin-treated mitochondria. pH difference ΔpH anaerobic has been estimated from buffering powers inner and outer phases change observed on lysing with Triton X-100. When (State 5), β-hydroxybutyrate, brought a state steady respiration either absence 4) 3) phosphate acceptor, changes pK medium recorded H+ ion-sensitive electrodes phase. absolute values have determined State 5 these transition States 4 3. The total protonmotive force Δp =ΔΨ– 59 oxidising β-hydroxybutyrate at 25° 250 mM sucrose near 7 is about 230 mV, which major component when effect translocation minimised. Under conditions permitting accumulation large quantity cation 6), not significantly different 4, but −ZΔpH. The effects changing mitochondrial suspensions uncoupling agent pulses acid, alkali, calcium salt ADP found accord chemiosmotic hypothesis. In particular 3 (ADP Pi present) 30 mV less than 4.