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

Abstract

Human serum albumin (HSA) serves as a natural depot of amyloid β peptide (Aβ). Improvement of Aβ binding to HSA should impede Alzheimer's disease (AD). We developed a method for quantitation of the interaction between monomeric Aβ40/42 and HSA using surface plasmon resonance spectroscopy. The dissociation constant of HSA complex with recombinant Aβ40/42 is 0.2–0.3 μM. Flemish variant of Aβ40 has 2.5–10-fold higher affinity to HSA. The parameters of the HSA-Aβ interaction are selectively sensitive to HSA binding of major plasma unsaturated fatty acids and Cu2+. Linoleic and arachidonic acids promote the HSA-Aβ42 interaction. The developed methodology for quantitation of HSA-Aβ interaction may serve as a tool for search of compounds favoring HSA-Aβ interaction, thereby preventing AD progression.