title: Characterization of amyloid beta peptides in cerebrospinal fluid by an automated immunoprecipitation procedure followed by mass spectrometry.
abstract: Pathogenic events in Alzheimer's disease are believed to involve an imbalance between the production and clearance of the neurotoxic 42 amino acid form of the beta-amyloid peptide (Abeta1-42). Although much is known about the production of Abeta1-42, many questions remain about its degradation. Here, we describe an optimized automated immunoprecipitation mass spectrometry method that enables accurate and rapid monitoring of the major Abeta isoforms in cerebrospinal fluid. Furthermore, we describe a technique of antibody immobilization, minimizing background signals. The identities of these Abeta products were confirmed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and nanoflow liquid chromatography and tandem mass spectrometry with a hybrid linear trap Fourier transform ion cyclotron resonance mass spectrometer. Finally, we report the finding of two novel Abeta peptides (Abeta2-17 and Abeta3-17).
authors.affiliation: Clinical Neurochemistry Laboratory, Department of Neuroscience and Physiology, University of Göteborg, Sahlgrenska University Hospital, S-431 80 Mölndal, Sweden. erik.portelius@neuro.gu.se
authors.forename: Erik
authors.initials: E
authors.lastname: Portelius
authors.forename: Ai Jun
authors.initials: AJ
authors.lastname: Tran
authors.forename: Ulf
authors.initials: U
authors.lastname: Andreasson
authors.forename: Rita
authors.initials: R
authors.lastname: Persson
authors.forename: Gunnar
authors.initials: G
authors.lastname: Brinkmalm
authors.forename: Henrik
authors.initials: H
authors.lastname: Zetterberg
authors.forename: Kaj
authors.initials: K
authors.lastname: Blennow
authors.forename: Ann
authors.initials: A
authors.lastname: Westman-Brinkmalm
mesh_terms: D000544:Alzheimer Disease / Q000378:metabolism; D016229:Amyloid beta-Peptides / Q000134:cerebrospinal fluid* / Q000737:chemistry*; D001331:Automation; D018929:Cell Culture Techniques / Q000379:methods; D002555:Cerebrospinal Fluid / Q000378:metabolism*; D002853:Chromatography, Liquid / Q000295:instrumentation* / Q000379:methods; D030562:Databases, Protein; D006801:Humans; D047468:Immunoprecipitation; D007167:Immunotherapy / Q000379:methods; D013058:Mass Spectrometry / Q000379:methods*; D010455:Peptides / Q000737:chemistry; D020033:Protein Isoforms; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000295:instrumentation* / Q000379:methods
chemical_list: D016229:Amyloid beta-Peptides; D010455:Peptides; D020033:Protein Isoforms