title: Nucleus factory on cavitation bubble for amyloid β fibril.
abstract: Structural evolution from monomer to fibril of amyloid β peptide is related to pathogenic mechanism of Alzheimer disease, and its acceleration is a long-running problem in drug development. This study reveals that ultrasonic cavitation bubbles behave as catalysts for nucleation of the peptide: The nucleation reaction is highly dependent on frequency and pressure of acoustic wave, and we discover an optimum acoustical condition, at which the reaction-rate constant for nucleation is increased by three-orders-of magnitudes. A theoretical model is proposed for explaining highly frequency and pressure dependent nucleation reaction, where monomers are captured on the bubble surface during its growth and highly condensed by subsequent bubble collapse, so that they are transiently exposed to high temperatures. Thus, the dual effects of local condensation and local heating contribute to dramatically enhance the nucleation reaction. Our model consistently reproduces the frequency and pressure dependences, supporting its essential applicability.
authors.affiliation: Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan.
authors.forename: Kichitaro
authors.initials: K
authors.lastname: Nakajima
authors.affiliation: Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan.
authors.forename: Hirotsugu
authors.initials: H
authors.lastname: Ogi
authors.affiliation: Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan.
authors.forename: Kanta
authors.initials: K
authors.lastname: Adachi
authors.affiliation: Institute of Molecular Embryology and Genetics, Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto 860-0811, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Noi
authors.affiliation: Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Hirao
authors.affiliation: Center for Reserch on Green Sustainable Chemistry, Tottori University, 4-101 Koyama-cho minami, Tottori, Tottori 680-8550, Japan.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Yagi
authors.affiliation: Institute for Protein Research, Osaka University, Yamadaoka 3-2, Suita, Osaka 565-0871, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Goto
mesh_terms: D000465:Algorithms; D016229:Amyloid beta-Peptides / Q000737:chemistry / Q000378:metabolism*; D008962:Models, Theoretical; D066329:Protein Aggregates / Q000528:radiation effects; D066263:Protein Aggregation, Pathological; D000069453:Ultrasonic Waves
chemical_list: D016229:Amyloid beta-Peptides; D066329:Protein Aggregates