Alzheimer's disease protein Aβ 1–42 does not disrupt isolated synaptic vesicles

Abstract

Synaptic vesicles are central to neurotransmission and cognition. Studies of the Alzheimer's disease (AD) associated peptide, amyloid beta (Aβ), suggest that it has the potential to non-specifically solubilize or permeabilize membranes and that it has detergent and pore-forming properties. Damage to the membrane or integrity of synaptic vesicles could compromise its function. We test the hypothesis that the intact synaptic vesicle is a direct site of attack by Aβ 1–42 in AD pathology by examining the properties of individual isolated vesicles exposed to Aβ 1–42. In particular, we compared the rate of leakage of dye molecules from synaptic vesicles, the rate of proton permeation across the membrane of the vesicle, and the rate of active proton transport into the vesicle interior in the presence and absence of Aβ 1–42. From these experiments, we conclude that isolated synaptic vesicles are not disrupted by Aβ 1–42.