title: Oxidation artifacts in the electrospray mass spectrometry of Abeta Peptide.
abstract: Gradual corrosion of stainless steel electrospray emitters under conditions of normal use generates surface irregularities that can promote electrical discharge. The increased emission current affects the electrochemical reactions associated with the spray process. When sampling the peptide Abeta(1-40), this is manifest by oxidation of methionine at position 35 to methionine sulfoxide. The resultant mass shift and reduced sensitivity can adversely affect H/D exchange experiments. These effects can be avoided by adding a redox buffer or (preferably) by repolishing the emitter, especially to a rounded geometry.
authors.affiliation: Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996-1600.
authors.forename: Maolian
authors.initials: M
authors.lastname: Chen
authors.forename: Kelsey D
authors.initials: KD
authors.lastname: Cook
mesh_terms: D016229:Amyloid beta-Peptides / Q000737:chemistry*; D016477:Artifacts; D002021:Buffers; D003343:Corrosion; D008715:Methionine / Q000031:analogs & derivatives / Q000032:analysis / Q000737:chemistry*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D010446:Peptide Fragments / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000592:standards*; D013193:Stainless Steel / Q000737:chemistry; D013499:Surface Properties
chemical_list: D016229:Amyloid beta-Peptides; D002021:Buffers; D010446:Peptide Fragments; C078592:amyloid beta-protein (1-40); D013193:Stainless Steel; D008715:Methionine; D010100:Oxygen; C013111:methionine sulfoxide