Effect of cholesterol on the formation of palmitate/Ca (2+) -activated pore in mitochondria and liposomes
Belosludtseva, N.V.; Belosludtsev, K.N.; Agafonov, A.V.; Mironova, G.D.
Biofizika 54(3): 464-470
2009
ISSN/ISBN: 0006-3029 PMID: 19569507 Document Number: 632915
The influenc of cholesterol on the formation of the mitochondrial cyclosporin A (CsA)-insensitive palmitate/Ca(2+)-activated pore has been studied. It has been established that increasing the cholesterol level in mitochondrial membranes results in an increase in the of rate of mitochondrial swelling induced by palmitic acid (> or = 20 microM) and Ca2+ (30 microM). This effect is not related to changes in the functional activity of organelles since cholesterol did not influence the mitochondrial respiration in different metabolic states. At the same time, it was shown that the palmitate/Ca(2+)-induced permeabilization of cholesterol-containing azolectin liposomes was Stronger than that of azolectin liposomes. It was found that, in the liposomal membrane, the Ca(2+)-induced phase separation of palmitic acid into distinct membrane domains takes place. The presence of cholesterol in membranes increases the extent of segregation.