title: SDS-PAGE analysis of Aβ oligomers is disserving research into Alzheimer´s disease: appealing for ESI-IM-MS.
abstract: The characterization of amyloid-beta peptide (Aβ) oligomer forms and structures is crucial to the advancement in the field of Alzheimer´s disease (AD). Here we report a critical evaluation of two methods used for this purpose, namely sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), extensively used in the field, and ion mobility coupled to electrospray ionization mass spectrometry (ESI-IM-MS), an emerging technique with great potential for oligomer characterization. To evaluate their performance, we first obtained pure cross-linked Aβ40 and Aβ42 oligomers of well-defined order. Analysis of these samples by SDS-PAGE revealed that SDS affects the oligomerization state of Aβ42 oligomers, thus providing flawed information on their order and distribution. In contrast, ESI-IM-MS provided accurate information, while also reported on the chemical nature and on the structure of the oligomers. Our findings have important implications as they challenge scientific paradigms in the AD field built upon SDS-PAGE characterization of Aβ oligomer samples.
authors.affiliation: Institute for Research in Biomedicine (IRB Barcelona), Baldiri Reixac 10, Barcelona 08028, Spain.
authors.forename: Rosa
authors.initials: R
authors.lastname: Pujol-Pina
authors.affiliation: Institute for Research in Biomedicine (IRB Barcelona), Baldiri Reixac 10, Barcelona 08028, Spain.
authors.forename: Sílvia
authors.initials: S
authors.lastname: Vilaprinyó-Pascual
authors.affiliation: Institute for Research in Biomedicine (IRB Barcelona), Baldiri Reixac 10, Barcelona 08028, Spain.
authors.forename: Roberta
authors.initials: R
authors.lastname: Mazzucato
authors.affiliation: Joint IRB-BSC Research Program in Computational Biology, Institute for Research in Biomedicine (IRB Barcelona), Baldiri Reixac 10, Barcelona 08028, Spain.
authors.forename: Annalisa
authors.initials: A
authors.lastname: Arcella
authors.affiliation: Mass Spectrometry Core Facility, Institute for Research in Biomedicine (IRB Barcelona), Baldiri Reixac 10, Barcelona 08028, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Vilaseca
authors.affiliation: Joint IRB-BSC Research Program in Computational Biology, Institute for Research in Biomedicine (IRB Barcelona), Baldiri Reixac 10, Barcelona 08028, Spain.|Department of Biochemistry and Molecular Biology, University of Barcelona, Diagonal 647, Barcelona 08028, Spain.
authors.forename: Modesto
authors.initials: M
authors.lastname: Orozco
authors.affiliation: Institute for Research in Biomedicine (IRB Barcelona), Baldiri Reixac 10, Barcelona 08028, Spain.
authors.forename: Natàlia
authors.initials: N
authors.lastname: Carulla
mesh_terms: D000544:Alzheimer Disease / Q000175:diagnosis / Q000378:metabolism* / Q000628:therapy; D016229:Amyloid beta-Peptides / Q000737:chemistry / Q000378:metabolism*; D035843:Biomedical Research / Q000379:methods; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods*; D006801:Humans; D008958:Models, Molecular; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D055503:Protein Multimerization; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013816:Thermodynamics
chemical_list: D016229:Amyloid beta-Peptides; D010446:Peptide Fragments; C078592:amyloid beta-protein (1-40); C075222:amyloid beta-protein (1-42)