Isolation of calcium-transporting lipid from the mitochondrial glycolipoprotein.

From the mitochondrial Ca2+-transporting glycolipoprotein (GLP) the lipid was isolated which induced Ca2+-translocation through bilayer lipid membranes. Electroconductivity of modified phospholipid membranes in the presence of CaCl2 is increased 150-200 times. At 10-fold CaCl2 gradient a generation of membrane potential is observed close to its theoretical value. It is shown that the lipid forms separate conductivity channels of 10 and 20 pS in the bilayer. The mode of action of GLP in the membrane is proposed. It is assumed that the carbohydrate part of GLP is a selective receptor-accumulator for Ca2+, whereas the function of the lipid component consists in forming channels in the bilayer.