Intact and Top-Down Characterization of Biomolecules and Direct Analysis Using Infrared Matrix-Assisted Laser Desorption Electrospray Ionization Coupled to FT-ICR Mass Spectrometry
We report the implementation of an infrared laser onto our previously reported matrix-assisted laser desorption electrospray ionization (MALDESI) source with ESI post-ionization yielding multiply charged peptides and proteins. Infrared (IR)-MALDESI is demonstrated for atmospheric pressure desorption and ionization of biological molecules ranging in molecular weight from 1.2 to 17 kDa. High resolving power, high mass accuracy single-acquisition Fourier transform ion cyclotron resonance (FT-ICR) mass spectra were generated from liquid- and solid-state peptide and protein samples by desorption with an infrared laser (2.94 μm) followed by ESI post-ionization. Intact and top-down analysis of equine myoglobin (17 kDa) desorbed from the solid state with ESI post-ionization demonstrates the sequencing capabilities using IR-MALDESI coupled to FT-ICR mass spectrometry. Carbohydrates and lipids were detected through direct analysis of milk and egg yolk using both UV- and IR-MALDESI with minimal sample preparation. Three of the four classes of biological macromolecules (proteins, carbohydrates, and lipids) have been ionized and detected using MALDESI with minimal sample preparation. Sequencing of O-linked glycans, cleaved from mucin using reductive β-elimination chemistry, is also demonstrated. © 2009 American Society for Mass Spectrometry.
Publication Source (Journal or Book title)
Journal of the American Society for Mass Spectrometry
Sampson, J., Murray, K., & Muddiman, D. (2009). Intact and Top-Down Characterization of Biomolecules and Direct Analysis Using Infrared Matrix-Assisted Laser Desorption Electrospray Ionization Coupled to FT-ICR Mass Spectrometry. Journal of the American Society for Mass Spectrometry, 20 (4), 667-673. https://doi.org/10.1016/j.jasms.2008.12.003