Detection of unusual lipid mixing in cholesterol-rich phospholipid bilayers: the long and the short of it.

Nearest-neighbor recognition studies have revealed that favored sterol-phospholipid associations can be reversed in a fluid bilayer that contains relatively long (high melting) and short (low melting) phospholipids, when the sterol content is sufficiently high; that is, like-lipids now become favored nearest-neighbors. A possible origin of this effect is briefly discussed.