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High resolution analysis of protein phosphorylation using capillary isoelectric focusing ‐ electrospray ionization ‐ mass spectrometry
Author(s) -
Wei Jing,
Yang Liyu,
Harrata A. Kamel,
Lee Cheng S.
Publication year - 1998
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.1150191316
Subject(s) - isoelectric focusing , chemistry , chromatography , mass spectrometry , electrospray ionization , electrospray , isoelectric point , extractive electrospray ionization , analytical chemistry (journal) , capillary electrophoresis–mass spectrometry , protein mass spectrometry , resolution (logic) , capillary action , ovalbumin , materials science , biochemistry , immune system , artificial intelligence , computer science , immunology , composite material , biology , enzyme
On‐line capillary isoelectric focusing (CIEF)‐electrospray ionization ‐ mass spectrometry (ESI‐MS) as a two‐dimensional separation system is employed for high resolution analysis of ovalbumin phosphorylation. On the basis of their differences in isoelectric point (p I ), the mono‐ and diphosphoovalbumins are separated and resolved in CIEF. The focused protein zones of mono‐ and diphosphoovalbumins are eluted by combining gravity with cathodic mobilization. At the end of the CIEF capillary, the mobilized ovalbumin zones are analyzed by mass spectrometry coupled on‐line to an electrospray interface with a coaxial sheath flow configuration. Additional ovalbumin variants within each of the mono‐ and diphosphoovalbumins, differing in their molecular masses due to glycosylation microheterogeneity, are easily distinguished by ESI‐MS.