title: Adsorption of amyloid beta-peptide at polymer surfaces: a neutron reflectivity study.
abstract: The adsorption of amyloid beta-peptide at hydrophilic and hydrophobic modified silicon-liquid interfaces was characterized by neutron reflectometry. Distinct polymeric films were used to obtain noncharged (Formvar), negatively (sodium poly(styrene sulfonate)) and positively charged (poly(allylamine hydrochloride)) hydrophilic as well as hydrophobic surfaces (polystyrene and a polysiloxane-dodecanoic acid complex). Amyloid beta-peptide was found to adsorb at positively charged hydrophilic and hydrophobic surfaces, whereas no adsorbed layer was detected on hydrophilic noncharged and negatively charged films. The peptide adsorbed at the positively charged film as patches, which were dispersed on the surface, whereas a uniform layer was observed at hydrophobic surfaces. The thickness of the adsorbed peptide layer was estimated to be approximately 20 A. The peptide formed a tightly packed layer, which did not contain water. These studies provide information about the affinity of the amyloid beta-peptide to different substrates in aqueous solution and suggest that the amyloid fibril formation may be driven by interactions with surfaces.
authors.affiliation: Max Planck Institute of Colloids and Interfaces, Research Campus Golm, Am Mühlenberg 1, 14476 Potsdam, Germany.
authors.forename: Sandra
authors.initials: S
authors.lastname: Rocha
authors.forename: Rumen
authors.initials: R
authors.lastname: Krastev
authors.forename: Andreas F
authors.initials: AF
authors.lastname: Thünemann
authors.forename: M Carmo
authors.initials: MC
authors.lastname: Pereira
authors.forename: Helmuth
authors.initials: H
authors.lastname: Möhwald
authors.forename: Gerald
authors.initials: G
authors.lastname: Brezesinski
mesh_terms: D000327:Adsorption; D016229:Amyloid beta-Peptides / Q000737:chemistry*; D003903:Deuterium; D057927:Hydrophobic and Hydrophilic Interactions; D009502:Neutrons; D010446:Peptide Fragments / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D012996:Solutions; D013499:Surface Properties; D014867:Water
chemical_list: D016229:Amyloid beta-Peptides; D010446:Peptide Fragments; D011108:Polymers; D012996:Solutions; C078592:amyloid beta-protein (1-40); D014867:Water; D003903:Deuterium