title: High resolution analysis of protein phosphorylation using capillary isoelectric focusing - electrospray ionization - mass spectrometry.
abstract: 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 (pI), 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.
authors.affiliation: Department of Chemistry and Ames Laboratory, Iowa State University, USA.
authors.forename: J
authors.initials: J
authors.lastname: Wei
authors.forename: L
authors.initials: L
authors.lastname: Yang
authors.forename: A K
authors.initials: AK
authors.lastname: Harrata
authors.forename: C S
authors.initials: CS
authors.lastname: Lee
mesh_terms: D019075:Electrophoresis, Capillary / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D007525:Isoelectric Focusing / Q000379:methods*; D007526:Isoelectric Point; D009682:Magnetic Resonance Spectroscopy; D008358:Mannose / Q000032:analysis; D013058:Mass Spectrometry / Q000379:methods*; D008970:Molecular Weight; D010047:Ovalbumin / Q000302:isolation & purification / Q000378:metabolism*; D010750:Phosphoproteins / Q000302:isolation & purification / Q000378:metabolism*; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D010766:Phosphorylation
chemical_list: D010750:Phosphoproteins; D010047:Ovalbumin; D010744:Phosphoric Monoester Hydrolases; D008358:Mannose