Nucleation–fibrillation dynamics of Aβ1-40 peptides on liquid–solid surface studied by total-internal-reflection fluorescence microscopy coupled with quartz-crystal microbalance biosensor. (12th May 2015)

• Record Type: Journal Article
• Authors: Hamada, Hiroki; Ogi, Hirotsugu; Noi, Kentaro; Yagi, Hisashi; Goto, Yuji; Hirao, Masahiko
• Is Part Of: Japanese journal of applied physics. Volume 54:Number 7(2015:Jul.)Supplement 1
• Publication Date: 2015-05-12
• Subjects: Physics -- Periodicals; 621.05
• DOI: 10.7567/JJAP.54.07HE01
• Languages: English
• ISSNs: 0021-4922

Abstract

Abstract: We have successfully developed the total-internal-reflection-fluorescence microscopy combined with a quartz-crystal microbalance (TIRFM-QCM) biosensor, and monitored the nucleation–fibrillation phenomenon of amyloid β1-40 peptide on the naked quartz surface. The cross-β-sheet structures were visualized with the TIRFM using the thioflavin-T (Th-T) label, and other unlabeled aggregates were detected through the frequency change of the 58-MHz wireless-electrodeless QCM throughout the aggregation reaction. The QCM response indicates significant adsorption of the peptides on the quartz surface at the early stage, which is followed by fibrillation. The non-cross-β-sheet oligomers are first formed, and nuclei appear in the oligomer region, from which fibrils originate and elongate. The two-color TIRFM observation was performed after the aggregation reaction with the Nile-red label as well as the ThT label for identifying nucleation from non-β-sheet regions. An aggregation model is proposed.