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Top‐down analysis of basic proteins by microchip capillary electrophoresis mass spectrometry
Author(s) -
Akashi Satoko,
Suzuki Koichi,
Arai Akihiro,
Yamada Naoyuki,
Suzuki EiIchiro,
Hirayama Kazuo,
Nakamura Shin,
Nishimura Yoshifumi
Publication year - 2006
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.2541
Subject(s) - chemistry , capillary electrophoresis , chromatography , mass spectrometry , capillary electrophoresis–mass spectrometry , capillary action , electrospray , analytical chemistry (journal) , resolution (logic) , microchannel , electrospray ionization , electrophoresis , nanotechnology , materials science , artificial intelligence , computer science , composite material
Abstract A system of microchip capillary electrophoresis/electrospray ionization mass spectrometry (µchip‐CE/ESI‐MS) for rapid characterization of proteins has been developed. Capillary electrophoresis (CE) enables rapid analysis of a sample present in very small quantity, such as at femtomole levels, at high resolution. Faster CE/MS analysis is expected by downsizing the normal capillary to the microchip (µchip) capillary. Although rapidity and high resolution are advantages of CE separation, electroosmotic flow (EOF) instability caused by the interaction between proteins and the microchannel surface results in low reproducibility in the analysis of basic proteins under neutral pH conditions. By coating the microchannel surface with a basic polymer, polyE‐323, basic proteins, which have pI values of over 7.5, could be separated and detected by µchip‐CE/MS on quadrupole (Q) and time‐of‐flight (TOF) hybrid instruments. By increasing the cone and collision voltages during the analysis by µchip‐CE/ESI‐MS of a small protein, some product ions, which contain the sequence information, could also be obtained, i.e., ‘top‐down’ analysis of the protein could be accomplished with this µchip‐CE/MS system. To our knowledge, this is the first report of ‘top‐down’ analysis of a protein by µchip‐CE/MS. Since it requires a much shorter time and a smaller sample amount for analysis than the conventional liquid chromatography (LC)/ESI‐MS method, µchip‐CE/MS promises to be suitable for the high‐throughput characterization of proteins. Copyright © 2006 John Wiley & Sons, Ltd.