No abstract

No abstract

The maximum redox potential difference between the NAD+/NADH couple and the succinate/fumarate couple generated during ATP-energized reduction of NAD+ by succinate in submitochondrial particles was measured, together with the electrochemical potential difference for protons (APH+). The presence of cyanide, the time-independence of the redox potential difference and the irrelevance of the initial redox state of the NAD+/NADH couple ensured that the experimental situation corresponded to a 'static-head condition' with APH+ as the input force and the redox potential difference as the output force, the flow of electrons having reached dynamic equilibrium. Consequently, the observed value of 1.6 for the ratio AGe/Aj?iH+ is interpreted as indicating that the H+/e-stoicheiometry at 'site 1' is 1.5 and that therefore the mechanism of the proton pump at 'site 1' is not of the group-translocation type (no direct e--H+ coupling).

No abstract

No abstract