Observation of multi-step conformation switching in beta-amyloid peptide aggregation by fluorescence resonance energy transfer.
We have observed the conformation switching of Abeta(11-25) in the course of amyloid aggregation by employing time-resolved fluorescence resonance energy transfer (FRET). The amyloid peptides undergo multi-step conformational changes during self-assembling such as random coil (monomers), collapsed coil (multimers), micellar structure, and extended beta-sheet in fibrils. We first identified the critical micelle concentration of Abeta(11-25) that occurs at ca. 3 microM for pH 5.0 and ca. 70 microM for pH 7.4. Our experimental results show clearly that the end-to-end distance of micellar Abeta(11-25) becomes much shorter than that of the collapsed coil or fibril structure.
Kim
Jiho
J
Laboratory of Fluorescence Nanoscopy, Department of Chemistry, and Division of Molecular Life Sciences, Ewha Womans University, Seoul 120-750, Republic of Korea.
Lee
Minyung
M
D016229:Amyloid beta-Peptides / Q000737:chemistry*; D031541:Fluorescence Resonance Energy Transfer; D008823:Micelles; D008954:Models, Biological; D010446:Peptide Fragments / Q000737:chemistry*; D011487:Protein Conformation
D016229:Amyloid beta-Peptides; D008823:Micelles; D010446:Peptide Fragments; C410220:amyloid beta-protein (11-25)