MITOCHONDRIAL PROTEOLIPIDS

A convenient procedure for extraction of mitochondrial proteolipids us ing the single-phase solvent mixture chloroform-methanol-water (1:2.0. 8 v/v) with subsequent concentration of proteolipids at an interface i s suggested. It allows the purification of proteolipids from the bulk of lipids. Rat liver proteolipids are tight complexes of phospholipids with several low-molecular-weight proteins (MW = 7-18 kD), about six phospholipid molecules per protein molecule with an average molecular weight of 10 kD. These complexes are destroyed at low pH. The composit ion of tightly bound phospholipids does not differ from that of the mi tochondrial phospholipids. P-31-NMR data show that the incorporation o f proteolipids into multibilayer liposomes results in the formation of nonbilayer structures.