The dispersion of cholesterol with phospholipids and glycolipids

✍ Scribed by Patrick J. McCabe; Colin Green

• Publisher: Elsevier Science
• Year: 1977
• Tongue: English
• Weight: 1008 KB
• Volume: 20
• Category: Article
• ISSN: 0009-3084
• DOI: 10.1016/0009-3084(77)90072-x

✦ Synopsis

Of the polar lipids studied (phospholipida and glycoiipids), only phosphatidylchohne and sphingomyelin can disperse in water with up to 2 mol cholesteroI/mol polar lipid. However, mixtures of phosphatidylethanolaminamine with small amounts of phosphatidylcholine and mixed lipids from mitochondria and myclin will also form sterol-rich disperdons. Steroids in which the 3@-OH group is replacred by an 0x0 function do not form such steroid-rich dispersions. Electron microscopy and optical rotatory diqeraion (ORD) show that sterols disperse with cerebrosides and gangliosidas to form cylindrical structures with the regions around C atoms 3 and 7 of the rtarol in leua polar anvirornnents than those they occupy in phospholipid lipoaomes.

It is proposed that choline-containing phosphohpids facilitate entry of &ml molecules into the outer leaflet of cell surface membranes but that the phospholipid composition itself will not give rise to an asymmetric diatributic;n of sterol in membranes with a high cholesterol content. Poklf 0.4 lipid dispersed hg/d) 0.2 0 P. J. McCrclbe and C. Green, Chlesteml/polar lipid dispersions 321 0369 0369 369