title: Capillary isoelectric focusing-electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry for protein characterization.
abstract: On-line combination of capillary isoelectric focusing (CIEF) with electrospray ionization Fourier transform ion cyclotron resonance (ESI-FTICR) mass spectrometry is demonstrated for high-resolution analysis of model proteins, human hemoglobin variants, and Escherichia coli proteins. The acquisition of high-resolution mass spectra of hemoglobin beta chains allows direct identification of hemoglobin variants A and C, differing in molecular mass by 1 Da. Direct mass determination of cellular proteins separated in the CIEF capillary is achieved using their isotopic envelopes obtained from ESI-FTICR. The factors which dictate overall performance of CIEF-ESI-FTICR, including duty cycle, mass resolution, scan rate, and sensitivity, are discussed in the context of protein variants and cell lysates analyzed in this study.
authors.affiliation: Department of Chemistry and Ames Laboratory, USDOE, Iowa State University 50011, USA.
authors.forename: L
authors.initials: L
authors.lastname: Yang
authors.forename: C S
authors.initials: CS
authors.lastname: Lee
authors.forename: S A
authors.initials: SA
authors.lastname: Hofstadler
authors.forename: L
authors.initials: L
authors.lastname: Pasa-Tolic
authors.forename: R D
authors.initials: RD
authors.lastname: Smith
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis; D003574:Cytochrome c Group / Q000737:chemistry; D004926:Escherichia coli / Q000737:chemistry; D006441:Hemoglobin A / Q000737:chemistry; D006444:Hemoglobin C / Q000737:chemistry; D006454:Hemoglobins / Q000737:chemistry; D006801:Humans; D007525:Isoelectric Focusing / Q000379:methods; D011506:Proteins / Q000032:analysis*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*
chemical_list: D001426:Bacterial Proteins; D003574:Cytochrome c Group; D006454:Hemoglobins; D011506:Proteins; D006444:Hemoglobin C; D006441:Hemoglobin A