title: Seed-dependent deposition behavior of Aβ peptides studied with wireless quartz-crystal-microbalance biosensor.
abstract: Real-time monitoring of the deposition processes of Aβ1-40 and Aβ1-42 peptides on various seeds has been performed using a 55 MHz wireless quartz-crystal microbalance (QCM) over long-time periods (~40 h). Dissolved peptide solutions were stirred for nucleation and growth of seeds at pH = 7.4 and 4.6, which were immobilized on the sensor chips. The isolated Aβ peptides were then flowed at the neutral pH, focusing on the interaction between the seeds and the monomers (or small multimers), excluding other interactions among seeds and other aggregates. The thioflavin-T fluorescence assay and atomic-force microscopy were used for evaluating structures of the seeds and deposited aggregates. The deposition rate, determined by the frequency decrease, is about 100 monomers/nm(2)/year in the case of fibril formation. The notable deposition behavior was observed in the deposition of Aβ1-40 peptide on Aβ1-42 seeds grown at the lower pH, which can be an important model for Alzheimer's disease.
authors.affiliation: Graduate School of Engineering Science, Osaka University, Machikaneyama 1-3, Toyonaka, Osaka 560-8531, Japan. ogi@me.es.osaka-u.ac.jp
authors.forename: Hirotsugu
authors.initials: H
authors.lastname: Ogi
authors.forename: Yuji
authors.initials: Y
authors.lastname: Fukunishi
authors.forename: Taiji
authors.initials: T
authors.lastname: Yanagida
authors.forename: Hisashi
authors.initials: H
authors.lastname: Yagi
authors.forename: Yuji
authors.initials: Y
authors.lastname: Goto
authors.forename: Masahiko
authors.initials: M
authors.lastname: Fukushima
authors.forename: Kentaro
authors.initials: K
authors.lastname: Uesugi
authors.forename: Masahiko
authors.initials: M
authors.lastname: Hirao
mesh_terms: D016229:Amyloid beta-Peptides / Q000737:chemistry*; D000906:Antibodies / Q000276:immunology; D052160:Benzothiazoles; D015374:Biosensing Techniques / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D018625:Microscopy, Atomic Force; D010446:Peptide Fragments / Q000737:chemistry*; D011485:Protein Binding; D058525:Quartz Crystal Microbalance Techniques / Q000379:methods*; D013050:Spectrometry, Fluorescence / Q000379:methods; D013844:Thiazoles / Q000737:chemistry; D059015:Wireless Technology
chemical_list: D016229:Amyloid beta-Peptides; D000906:Antibodies; D052160:Benzothiazoles; D010446:Peptide Fragments; D013844:Thiazoles; C078592:amyloid beta-protein (1-40); C075222:amyloid beta-protein (1-42); C009462:thioflavin T