title: A modified protocol to prepare seed-free starting solutions of amyloid-β (Aβ)₁₋₄₀ and Aβ₁₋₄₂ from the corresponding depsipeptides.
abstract: Preparing reliable, seed-free stock solutions of the highly amyloidogenic peptides amyloid-β (Aβ) is difficult. Besides the formation of aggregates during synthesis and storage, dissolution of the peptide is a critical step because vortexing can induce aggregation. To overcome this, synthesis of the more water-soluble depsi-Aβ(1-42) peptide, from which the native sequence is easily obtained, has been suggested. We further refined this technique, including a cutoff filtration step and switching the depsipeptide in basic conditions, to stabilize the formed native peptide. The obtained solutions of native Aβ(1-40) and Aβ(1-42) peptides were homogeneous and aggregate free, as indicated by thioflavin T and circular dichroism analysis.
authors.affiliation: Department of Biochemistry and Molecular Pharmacology, Instituto di Ricerche Farmacologiche "Mario Negri", 20156 Milano, Italy. marten.beeg@chem.ethz.ch
authors.forename: Marten
authors.initials: M
authors.lastname: Beeg
authors.forename: Matteo
authors.initials: M
authors.lastname: Stravalaci
authors.forename: Antonio
authors.initials: A
authors.lastname: Bastone
authors.forename: Mario
authors.initials: M
authors.lastname: Salmona
authors.forename: Marco
authors.initials: M
authors.lastname: Gobbi
mesh_terms: D016229:Amyloid beta-Peptides / Q000737:chemistry*; D052160:Benzothiazoles; D002942:Circular Dichroism; D047630:Depsipeptides / Q000737:chemistry*; D010446:Peptide Fragments / Q000737:chemistry*; D012996:Solutions / Q000737:chemistry; D013844:Thiazoles / Q000737:chemistry
chemical_list: D016229:Amyloid beta-Peptides; D052160:Benzothiazoles; D047630:Depsipeptides; D010446:Peptide Fragments; D012996:Solutions; D013844:Thiazoles; C078592:amyloid beta-protein (1-40); C075222:amyloid beta-protein (1-42); C009462:thioflavin T