Capillary electrophoresis off-line matrix-assisted laser desorption/ionisation mass spectrometry of intact and digested proteins using cationic-coated capillaries.
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.
Zuberovic
Aida
A
Department of Analytical Chemistry, Biomedical Centre, Uppsala University, PO Box 599, SE-751 24 Uppsala, Sweden.
Ullsten
Sara
S
Hellman
Ulf
U
Markides
Karin E
KE
Bergquist
Jonas
J
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
D010455:Peptides; D011506:Proteins