title: Acceleration of the depolymerization of amyloid β fibrils by ultrasonication.
abstract: Amyloid fibrils, rigid and filamentous aggregates associated with various diseases, are often difficult to depolymerize into monomers. Ultrasonication is a strong agitation that accelerates nucleation above the critical concentration of amyloid fibrillation. We examined the effects of ultrasonication on the fibrils of amyloid β(1-40) as well as on monomers. Ultrasonic pulses accelerated spontaneous fibrillation when the peptide concentration was above 1μM. On the other hand, ultrasonic pulses accelerated the depolymerization of fibrils into monomers at 1μM. These results indicate that, although amyloid fibrillation is a reversible process determined by thermodynamic stability, kinetically trapped supersaturation and physical difficulty of dissolving rigid fibrils prevent the smooth phase transitions. We propose that, in addition to accelerating the nucleation of fibrillation and fragmentation of fibrils above the critical concentration, ultrasonication is useful for dissolving fibrils below the critical concentration.
authors.affiliation: Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Yagi
authors.forename: Kyohei
authors.initials: K
authors.lastname: Hasegawa
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Yoshimura
authors.forename: Yuji
authors.initials: Y
authors.lastname: Goto
mesh_terms: D000682:Amyloid / Q000737:chemistry*; D016229:Amyloid beta-Peptides / Q000737:chemistry*; D006801:Humans; D010446:Peptide Fragments / Q000737:chemistry*; D014465:Ultrasonics
chemical_list: D000682:Amyloid; D016229:Amyloid beta-Peptides; D010446:Peptide Fragments; C078592:amyloid beta-protein (1-40)
keywords: Amyloid fibril; Amyloid β; Aβ(1–40); CD; Solubility; Supersaturation; TEM; ThT; Ultrasonication; amyloid β peptide composed of 40 residues; circular dichroism; thioflavin T; transmission electron microscopy