title: Capillary electrophoresis off-line matrix-assisted laser desorption/ionisation mass spectrometry of intact and digested proteins using cationic-coated capillaries.
abstract: Capillary electrophoresis (CE) was coupled off-line with matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOFMS) for the analysis of proteins and peptides. CE fractions were collected directly on a matrix-coated MALDI target, using a sheath-flow interface. Protein adsorption during CE separations was prevented by coating the capillaries with the physically adsorbed, cationic polymer PolyE-323. The CE/MALDI-MS system was used for the analysis of model proteins and peptides at physiological pH as well as analysis of proteins in tear fluid. Moreover, tryptic on-target digestion of the collected protein fractions, with subsequent MALDI-MS and MS/MS peptide analysis, was demonstrated.
authors.affiliation: Department of Analytical Chemistry, Biomedical Centre, Uppsala University, PO Box 599, SE-751 24 Uppsala, Sweden.
authors.forename: Aida
authors.initials: A
authors.lastname: Zuberovic
authors.forename: Sara
authors.initials: S
authors.lastname: Ullsten
authors.forename: Ulf
authors.initials: U
authors.lastname: Hellman
authors.forename: Karin E
authors.initials: KE
authors.lastname: Markides
authors.forename: Jonas
authors.initials: J
authors.lastname: Bergquist
mesh_terms: D019075:Electrophoresis, Capillary / Q000295:instrumentation* / Q000379:methods; D010455:Peptides / Q000032:analysis*; D011506:Proteins / Q000032:analysis*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000295:instrumentation* / Q000379:methods; D013666:Tears / Q000737:chemistry
chemical_list: D010455:Peptides; D011506:Proteins