Efficient Lipid Peroxidation Catalyzed by Amyloid-Beta-Copper Complex: Observation of Chemical Oscillation and Chaos

Abstract

Biochemical oscillations are ubiquitous in living systems, occurring in many contexts such as circadian rhythms, DNA synthesis etc. In contrast, in vitro chemical oscillators are limited to only a few examples based largely on oxyhalogen chemistry, such as the well-known Belousov-Zhabotinsky reaction. Using a BODIPY lipid peroxidation probe, we have found that lipid membrane bound Aβ-Cu complexes function as peroxidases that catalyze the lipid peroxidation much more efficiently than free copper ions though the later generates more reaction oxygen species (ROS). Under low Aβ and probe concentrations (<1% total lipid), the reaction system starts to oscillate along with exponential decay kinetics. Our observations may have implications for the pathological roles of Aβ-Cu complexes in neuronal membrane damage.