title: Solid-Phase Synthesis and Characterization of N-Terminally Elongated Aβ-3-x -Peptides.
abstract: In addition to the prototypic amyloid-β (Aβ) peptides Aβ1-40 and Aβ1-42 , several Aβ variants differing in their amino and carboxy termini have been described. Synthetic availability of an Aβ variant is often the key to study its role under physiological or pathological conditions. Herein, we report a protocol for the efficient solid-phase peptide synthesis of the N-terminally elongated Aβ-peptides Aβ-3-38 , Aβ-3-40 , and Aβ-3-42 . Biophysical characterization by NMR spectroscopy, CD spectroscopy, an aggregation assay, and electron microscopy revealed that all three peptides were prone to aggregation into amyloid fibrils. Immunoprecipitation, followed by mass spectrometry, indicated that Aβ-3-38 and Aβ-3-40 are generated by transfected cells even in the presence of a tripartite β-site amyloid precursor protein cleaving enzyme 1 (BACE1) inhibitor. The elongated Aβ peptides starting at Val(-3) can be separated from N-terminally-truncated Aβ forms by high-resolution isoelectric-focusing techniques, despite virtually identical isoelectric points. The synthetic Aβ variants and the methods presented here are providing tools to advance our understanding of the potential roles of N-terminally elongated Aβ variants in Alzheimer's disease.
authors.affiliation: Department Chemie, Technische Universität Dresden, Bergstrasse 66, 01069, Dresden, Germany.
authors.forename: Isaak
authors.initials: I
authors.lastname: Beyer
authors.affiliation: Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany.|German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Str. 3a, 37075, Göttingen, Germany.
authors.forename: Nasrollah
authors.initials: N
authors.lastname: Rezaei-Ghaleh
authors.affiliation: Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Georg-August-Universität, 37075, Göttingen, Germany.
authors.forename: Hans-Wolfgang
authors.initials: HW
authors.lastname: Klafki
authors.affiliation: Max Planck Institute for Experimental Medicine, Proteomics Group, 37075, Göttingen, Germany.|Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, University of Göttingen, Humboldtallee 23, 37073, Göttingen, Germany.
authors.forename: Olaf
authors.initials: O
authors.lastname: Jahn
authors.affiliation: University of Duisburg-Essen, 45141, Essen, Germany.
authors.forename: Ute
authors.initials: U
authors.lastname: Haußmann
authors.affiliation: German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Str. 3a, 37075, Göttingen, Germany. Markus.Zweckstetter@dzne.de, jens.wiltfang@med.uni-goettingen.de.|Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Georg-August-Universität, 37075, Göttingen, Germany. Markus.Zweckstetter@dzne.de, jens.wiltfang@med.uni-goettingen.de.
authors.forename: Jens
authors.initials: J
authors.lastname: Wiltfang
authors.affiliation: Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany.|German Center for Neurodegenerative Diseases (DZNE), Von-Siebold-Str. 3a, 37075, Göttingen, Germany.|Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Göttingen, University of Göttingen, Humboldtallee 23, 37073, Göttingen, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Zweckstetter
authors.affiliation: Department Chemie, Technische Universität Dresden, Bergstrasse 66, 01069, Dresden, Germany. hans-joachim.knoelker@tu-dresden.de.
authors.forename: Hans-Joachim
authors.initials: HJ
authors.lastname: Knölker
mesh_terms: D000595:Amino Acid Sequence; D016229:Amyloid beta-Peptides / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism; D052160:Benzothiazoles; D002942:Circular Dichroism; D006801:Humans; D007700:Kinetics; D013058:Mass Spectrometry; D008854:Microscopy, Electron; D019906:Nuclear Magnetic Resonance, Biomolecular; D060327:Solid-Phase Synthesis Techniques; D013844:Thiazoles / Q000737:chemistry / Q000378:metabolism
chemical_list: D016229:Amyloid beta-Peptides; D052160:Benzothiazoles; D013844:Thiazoles; C009462:thioflavin T
keywords: Alzheimer's disease; aggregation; biomarkers; biophysical characterization; solid-phase peptide synthesis