title: Transmembrane movement of cholesterol in small unilamellar vesicles detected by cholesterol oxidase.
abstract: Greater than 90% of the cholesterol in small unilamellar vesicles composed of egg lecithin and cholesterol (molar ratio 1:0.7) was oxidized by a cholesterol oxidase from Brevibacterium sp., with a single time constant and a half-time of 1 min at 37 degrees C. The enzyme preparation used was at least 95% pure and possessed no detectable phospholipase C activity. Since cholesterol is present in both halves of the bilayer, it was concluded that transmembrane movement of cholesterol in these vesicles occurs with a half-time of 1 min or less at 37 degrees C.
mesh_terms: D015096:3-Hydroxysteroid Dehydrogenases / Q000378:metabolism*; D000818:Animals; D001951:Brevibacterium / Q000201:enzymology; D002645:Chickens; D002784:Cholesterol / Q000032:analysis; D002789:Cholesterol Oxidase / Q000378:metabolism*; D004530:Egg Yolk; D005260:Female; D007444:Inulin; D007700:Kinetics; D008081:Liposomes; D010713:Phosphatidylcholines
chemical_list: D008081:Liposomes; D010713:Phosphatidylcholines; D007444:Inulin; D002784:Cholesterol; D015096:3-Hydroxysteroid Dehydrogenases; D002789:Cholesterol Oxidase