Oxysterol-lnduced Rearrangement of the Liquid-Ordered Phase: A Possible Link to Alzheimer's Disease?

摘要

Nearest-neighbor recognition measurements have been made for an exchangeable phospholipid (A) interacting with an exchangeable form of cholesterol (B) in host membranes derived from 1,2-dipalmitoyl-sn-glycero-3-phosphocholine and varying concentrations of cholesterol, 7β-hydroxycholesterol (7β-OH), and 25-hydroxycholesterol (25-OH). Whereas partial replacement of cholesterol with 7β-OH strengthens the association between A and B, a similar substitution with 25-OH weakens this association. A model that accounts for this dichotomy, and the possible relevance of these findings to the cytotoxicity of 7β-OH and to Alzheimer's disease are briefly discussed.