Characterization of Hydrophobic Peptides by Atmospheric Pressure Photoionization-Mass Spectrometry and Tandem Mass Spectrometry

• Published in: Analytical chemistry (Washington) 2003-11, Vol.75 (21), p.5961-5968
• Main Authors: Delobel, Arnaud, Halgand, Frédéric, Laffranchise-Gosse, Barbara, Snijders, Henri, Laprévote, Olivier
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Aminoacids, peptides. Hormones. Neuropeptides; Analytical chemistry; Analytical, structural and metabolic biochemistry; Angiotensin II - chemistry; Atmosphere; Atmospheric Pressure; Biological and medical sciences; Bradykinin - chemistry; Chemistry; Chromatographic methods and physical methods associated with chromatography; Chromatography, Liquid; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Gramicidin - chemistry; Hydrophobic and Hydrophilic Interactions; Ions - chemistry; Mass Spectrometry - methods; Molecular Sequence Data; Other chromatographic methods; Peptides; Peptides - chemistry; Photochemistry; Photolysis; Photons; Polyethylene Glycols - chemistry; Pressure; Proteins; Spectrometric and optical methods; Spectrometry, Mass, Electrospray Ionization; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Temperature; Ultraviolet Rays
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac034532k

The use of photoionization at atmospheric pressure shows great potential for the mass analysis of large apolar or hydrophobic peptides. Mass spectra that were obtained using this technique showed mainly singly charged ions. While polar peptides spectra do not produce fragment ions, others lead to B-type or C-type in-source fragmentation. These dissociation reactions, which could involve electron capture dissociation processes in the case of the C-type ions, are observed for hydrophobic peptides. Both the compatibility of this ionization mode with reversed- or normal-phase liquid chromatographic separation and its sensitivity allow liquid chromatography coupling to both mass spectrometry and tandem mass spectrometry for the analyses of hydrophobic peptide mixtures. Atmospheric pressure photoionization seems to be an interesting alternative method to study hydrophobic peptides that are not easily ionizable by more classical ionization techniques such as electrospray ionization and matrix-assisted laser desorption/ionization.