The binding of monomeric amyloid ß peptide to serum albumin is affected by major plasma unsaturated fatty acids.

Human serum albumin (HSA) serves as a natural depot of amyloid ß peptide (Aß). Improvement of Aß binding to HSA should impede Alzheimer's disease (AD). We developed a method for quantitation of the interaction between monomeric Aß40/42 and HSA using surface plasmon resonance spectroscopy. The dissociation constant of HSA complex with recombinant Aß40/42 is 0.2-0.3 µM. Flemish variant of Aß40 has 2.5-10-fold higher affinity to HSA. The parameters of the HSA-Aß interaction are selectively sensitive to HSA binding of major plasma unsaturated fatty acids and Cu2+. Linoleic and arachidonic acids promote the HSA-Aß42 interaction. The developed methodology for quantitation of HSA-Aß interaction may serve as a tool for search of compounds favoring HSA-Aß interaction, thereby preventing AD progression.