OH· Radical Production Induces Direct Enhancement of the Amyloïd β Protein/Chondroitin Sulfate Binding: Inhibition by Potentially Radical Scavengers, a Biochromatographic and Thermodynamic Model

Abstract

β-Amyloid (Aβ) is a major component of the senile plaques characteristic of Alzheimer disease (AD). Chondroitin sulfate (CS) and glycoaminoglycan (GAG) are also localized throughout the senile plaques in AD. In previous studies, the interaction of the Aβ protein with CS immobilized on a chromatographic support and the role of aluminum and copper cations was studied using a molecular chromatographic approach [1, 2]. Here, we demonstrated the direct implication of OH· radical formation on this binding via a novel analytical procedure. The binding of Aβ amyloid on CS was accompanied by an OH· radical uptake. The Aβ–CS complex was stabilized by the OH· radical via the creation of about one to two hydrogen bonds. The addition in the medium of a radical scavenger allowed decreasing the Aβ/CS association and thus confirmed the positive role of these compounds in amyloidosis.