PERMEABILITY INDUCED IN ARTIFICIAL MEMBRA NES AFTER INCORPORATION OF ATP ADP ANTIPORTER FROM BOVINE HEART-MITOCHONDRIA

In the present paper the hypothesis concerned with the ability of the ATP/ADP antiporter to increase the phospholipid membranes conductance (to function as an uncoupling protein) is examined in model systems (p roteoliposomes or planar BLM). The proton conductance of the ANT-bacte riorhodopsin proteoliposome membrane is shown to be of an order higher than that of bacteriorhodopsin - only one. Mersalyl treatment of ANT- bacteriorhodopsin proteoliposomes causes formation of high conductance channel-like structures in the membrane. The main features of this ch annel are shown to be similar to those of the so-called multiple condu ctance channel (MCC) of the linear mitochondrial membrane (Kinnally et al. // J. Bioenerg. and Biomembr. 1989. V. 21. P. 497-506). A high co nductance of the single channel (approximately 2.2 nS) and its non-sel ectivity for K+, Na+, H+, Cl- demonstrate that hydrophilic pore format ion occurred in the mersalyl-treated membrane with reconstituted ANT. It is assumed that ANT might function as a permeability transition por e-forming protein in mitochondria.