Effect of sucrose on formation of the β-amyloid fibrils and D-aspartic acids in Aβ1-42

Beta-amyloid peptide 1-42 is a major peptide constituent of β-amyloid fibrils. We investigated the role of sucrose on the deposition and the D-aspartic acid formation in an amyloidogenic peptide 1-42 under physiological conditions. From analyses using thioflavine-T fluorometric assay and electronmicroscopic spectroscopy after 60 h incubation at 37°C, it was found that sucrose retarded the fibril formation in the amyloidogenic peptide. The retardation of the formation of amyloid fibrils by sucrose was suggested to be not due to viscosity but due to disturbance of the assemlby of α-helix containing peptides. Moreover, we showed that the formation of D-aspartyl residue, which is found in β-amyloid fibrils from Alzheimer disease brains, in the amyloidogenic peptide was also retarded in the presence of sucrose.