Alzheimer's amyloid beta interaction with normal human plasma high density lipoprotein: association with apolipoprotein and lipids.

We report studies of the interaction of Alzheimer's amyloid beta protein (A beta) with normal human plasma high density lipoprotein (HDL), aiming to clarify to which lipoprotein (LP) structural constituent (apolipoprotein or lipid) soluble A beta is primarily bound. Purified HDLs were incubated with biotinylated A beta 1-40 followed by LP repurification by size exclusion (SE) HPLC. SDS-PAGE, immunoblot and N-terminal sequence analysis of the biotin-A beta positive protein bands revealed that A beta is bound to many apolipoproteins of the HDL, mainly apoA-I, apoA-II, apoE and apoJ.

Multiple inhibitory effects of Alzheimer's peptide Abeta1-40 on lipid biosynthesis in cultured human HepG2 cells.

Herein we describe the inhibitory effect of the synthetic peptide Abeta1-40, homologous to the major high-density lipoprotein-associated species of Alzheimer's amyloid beta protein (Abeta), on lipid biosynthesis in human hepatic HepG2 cells. This culture synthesizes various lipids from [14C]acetate as a precursor. Treatment of cells with different concentrations of Abeta1-40 decreased the syntheses of various radiolabeled lipid species.