Phosphatidylcholine exchange between the boundary lipid and bilayer domains in cytochrome oxidase containing membranes.

摘要: A phospholipid spin label, 16-doxylphosphatidylcholine, is employed in a study of lipid--protein interactions cytochrome oxidase containing membranes. Two methods are used to label the membranous oxidase: dispersion cholate with subsequent detergent removal, and fusion vesicles pure absence detergent. fraction immobilized, which calculated fall range 0.17--0.21 mg phospholipid/mg protein (0.15--0.19 after correction for lipids not extracted by chloroform--methanol). This narrow values independent labeling, isolation, lipid depletion within experimental error. When labeling utilized, patches phosphatidylcholine diffuse plane bilayer, become diluted, demonstrate exchange bound phospholipid. These observations evidence that boundary lipid, as reflected partitioning equilibrium adjacent bilayer regions it consists relatively constant amount associated hydrophobic portion protein.