A polyamine coating for enhanced capillary electrophoresis-electrospray ionization-mass spectrometry of proteins and peptides.
A procedure for enhanced capillary electrophoresis-electrospray ionization-mass spectrometry (CE-ESI-MS) of proteins is presented. The use of a newly presented capillary coating, PolyE-323, provided fast separations of typically a few minutes with high efficiency, good deactivation, and no bleeding into the mass spectrometer. Capillaries coated with PolyE-323 showed high stability over a range of pH 2-10, and tolerance towards methanol and acetonitrile, two modifiers commonly used in CE-ESI-MS. Due to the speed and simplicity of the coating procedure, the polymeric surface could, if necessary, easily be regenerated. This capability is especially valuable when working with samples of complex matrix, where a capillary surface cleaning step might be desired in order to eliminate possible memory effects. The potential of PolyE-323-coated capillaries in bioanalysis using CE-ESI-MS was demonstrated by analyzing peptides and proteins up to 66 kDa using time of flight (TOF)-MS. Due to the stable, anodal electroosmotic flow generated by the coating, the use of a sheathless ESI interface was enabled, demonstrated in peptide analysis with attomole sensitivity. The fast on-line CE-ESI-TOF system using PolyE-323-coated capillaries provided efficient separation and detection of a large number of peaks in a short time, exemplified by the analysis of a tryptic digest of bovine serum albumin (BSA). The capability of the developed capillary surface coating was demonstrated by the separation of human plasma and cerebrospinal fluid (CSF).
Ullsten
Sara
S
Department of Analytical Chemistry, Biomedical Centre, Uppsala University, Uppsala, Sweden.
Zuberovic
Aida
A
Department of Analytical Chemistry, Biomedical Centre, Uppsala University, Uppsala, Sweden.
Wetterhall
Magnus
M
Department of Analytical Chemistry, Biomedical Centre, Uppsala University, Uppsala, Sweden.
Hardenborg
Emilia
E
Department of Analytical Chemistry, Biomedical Centre, Uppsala University, Uppsala, Sweden.
Markides
Karin E
KE
Department of Analytical Chemistry, Biomedical Centre, Uppsala University, Uppsala, Sweden.
Bergquist
Jonas
J
Department of Analytical Chemistry, Biomedical Centre, Uppsala University, Uppsala, Sweden.
D000097:Acetonitriles / Q000737:chemistry; D000818:Animals; D002417:Cattle; D002555:Cerebrospinal Fluid / Q000737:chemistry; D019075:Electrophoresis, Capillary / Q000379:methods*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D000432:Methanol / Q000737:chemistry; D010455:Peptides / Q000032:analysis* / Q000737:chemistry; D010949:Plasma / Q000737:chemistry; D011073:Polyamines / Q000737:chemistry*; D011506:Proteins / Q000032:analysis* / Q000737:chemistry; D012710:Serum Albumin, Bovine / Q000032:analysis; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013997:Time Factors; D014357:Trypsin / Q000378:metabolism
D000097:Acetonitriles; D010455:Peptides; D011073:Polyamines; D011506:Proteins; D012710:Serum Albumin, Bovine; D014357:Trypsin; D000432:Methanol; C032159:acetonitrile