Generation and detection of multiply-charged peptides and proteins by matrix-assisted laser desorption electrospray ionization (MALDESI) Fourier transform ion cyclotron resonance mass spectrometry.
We report the coupling of a hybrid ionization source, matrix-assisted laser desorption electrospray ionization (MALDESI), to a Fourier transform-ion cyclotron resonance mass spectrometer (FT-ICR MS). The details of the source design and initial data are presented. Analysis of peptides and proteins ranging from 1 to 8.6 kDa resulted in high resolving power single-acquisition FT-ICR mass spectra with average charge-states highly correlated to those obtained by nanoESI, thus, providing strong evidence that the ESI process dictates the observed charge-state distribution. Importantly, unlike the recently introduced electrospray assisted laser desorption ionization (ELDI) source reported by Shiea and coworkers [1, 2], the data we have obtained to date rely on the use of an organic acid matrix. The results presented herein provide insight into the charging mechanism of this emerging ionization approach, while also expanding the utility of FT-ICR MS for top-down protein and complex mixture analysis.
Sampson
Jason S
JS
W. M. Keck FT-ICR Mass Spectrometry Laboratory, Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, USA.
Hawkridge
Adam M
AM
Muddiman
David C
DC
D000465:Algorithms; D017357:Cyclotrons; D010449:Peptide Mapping / Q000379:methods*; D010455:Peptides / Q000032:analysis*; D011506:Proteins / Q000032:analysis*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*; D055672:Static Electricity
D010455:Peptides; D011506:Proteins