DIRECT TRANSDUCTION OF ENERGY BY DITHIOL-DISULFIDE INTERCONVERSION

The principle of the formation and functioning of supercomplexes composed of genetically independent transport systems is proposed. The formation of supercomplexes occurs in changing from intraprotein disulfide bonds to interprotein ones, i.e. disulfides serve as a dynamic interface between two membrane systems. Disulfide can also serve as a bridge for direct energy transfer: a primary energy-donating system provides a secondary mechanism for hydrogen atoms and energy for reducing thiols on the latter. The subsequent conversion of 2SH to S-S leads to energy release of 35 kJ mol-1 necessary for operating the secondary system. A Δμ-H+ is the compulsory factor for direct transduction of energy because Δμ-H+ determines at least the Km of transport proteins. A simple experiment is proposed to demonstrate direct transfer of energy from electron transfer chain to ATP synthase under gradientless conditions. © 1990 Academic Press Limited All rights reserved.