title: Rapid aggregation and assembly in aqueous solution of A beta (25-35) peptide.
abstract: The highly toxic A beta (25-35) is a peculiar peptide that differs from all the other commonly studied beta-amyloid peptides because of its extremely rapid aggregation properties and enhanced neurotoxicity. We investigated A beta (25-35) aggregation in H2O at pH 3.0 and at pH 7.4 by means of in-solution analyses. Adopting UV spectroscopy, Congo red spectrophotometry and thioflavin T fluorimetry, we were able to quantify, in water, the very fast assembling time necessary for A beta (25-35) to form stable insoluble aggregates and their ability to seed or not seed fibril growth. Our quantitative results, which confirm a very rapid assembly leading to stable insoluble aggregates of A beta (25-35) only when incubated at pH 7.4, might be helpful for designing novel aggregation inhibitors and to shed light on the in vivo environment in which fibril formation takes place.
authors: Department of Molecular Biology, University of Siena, Siena, Italy.
authors: Lia
authors: L
authors: Millucci
authors: Roberto
authors: R
authors: Raggiaschi
authors: Davide
authors: D
authors: Franceschini
authors: Georg
authors: G
authors: Terstappen
authors: Annalisa
authors: A
authors: Santucci
mesh_terms: D016229:Amyloid beta-Peptides / Q000737:chemistry*; D052160:Benzothiazoles; D003224:Congo Red / Q000494:pharmacology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D015233:Models, Statistical; D009391:Nephelometry and Turbidimetry / Q000379:methods; D009498:Neurotoxins / Q000737:chemistry; D010446:Peptide Fragments / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry; D013050:Spectrometry, Fluorescence / Q000379:methods; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D013844:Thiazoles / Q000737:chemistry; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D016229:Amyloid beta-Peptides; D052160:Benzothiazoles; D009498:Neurotoxins; D010446:Peptide Fragments; D010455:Peptides; D013844:Thiazoles; C074636:amyloid beta-protein (25-35); D014867:Water; C009462:thioflavin T; D003224:Congo Red