Analytical method for beta-amyloid fibrils using CE-laser induced fluorescence and its application to screening for inhibitors of beta-amyloid protein aggregation.

More than 20 million people are suffering from Alzheimer's disease, and the number of patients will dramatically increase with the arrival of an aging society unless preventive or curative medications are discovered. A fast and sensitive analytical method for beta-amyloid (Abeta) aggregates was developed by the combination of CE-laser induced fluorescence and the fluorescence reagent, thioflavine T. The developed method separates two different fibrils within 5 min. The first peak, which migrated at approximately 4 min, was supposed to be derived from a precursor of a fibril that migrated at approximately 3.5 min. The developed method was also applicable to the high-throughput screening of the Abeta aggregation inhibitors, which was expected to be an effective therapeutic agent candidate of Alzheimer's disease. Three compounds (daunomycin, 3-indolepropionic acid (3-IPA), melatonin) were used for the assay. The order of the antiaggregation activity of these compounds was daunomycin > 3-IPA > melatonin, which was the same as that of the reported one. These results suggest that this analytical method may be used to analyze the Abeta fibrils and identify potential therapeutic agents for the treatment of Alzheimer's disease.