CAPILLARY ELECTROPHORESIS FOURIER-TRANSFORM ION-CYCLOTRON RESONANCE MASS-SPECTROMETRY WITH SUSTAINED OFF-RESONANCE IRRADIATION FOR THE CHARACTERIZATION OF PROTEIN AND PEPTIDE MIXTURES

A new approach to protein and peptide analysis that involves the coupl ing of on-line capillary electrophoresis-electrospray ionization Fouri er transform ion cyclotron resonance mass spectrometry with a variatio n of sustained off-resonance irradiation is described. With this techn ique, multiple irradiation frequencies are broadcast simultaneously, w hich yields fragmentation of species at different mass-to-charge ratio values from the same waveform. In conjunction with capillary electrop horesis, this technique can provide sequence information from small am ounts of proteins or peptides in complex mixtures. Initial results obt ained from a mixture of gramicidin S (1141 u), bee venom melittin (284 5 u), and equine apomyoglobin (16,951 u) are presented.