Fragmentation studies of oligosaccharides and glycopeptides by using FTICR MS with a Mid-Infrared Free-Electron Laser

CARB 79

Kazuhiko Fukui, k-fukui@aist.go.jp, Computational Biology Research Center (CBRC), National Institute of Advanced Industrial Science and Technology (AIST), 2-41-6 Aomi, Koto-ku, Tokyo, 135-0064, Japan
We investigated the fragmentation behavior of the protonated glycopeptides and sodiated oligosaccharides using infrared multiple photodissociation (IRMPD) with a tunable IR free electron laser (FEL) in conjunction with Fourier-Transform Ion Cyclotron Resonance (FTICR) mass spectrometry (MS). The fragmentation behavior of these parent ions was probed by monitoring the fragmentation of the ions induced by IRMPD in the IR wavelength range of 5.7–9.5 µm. The gas-phase IRMPD spectroscopy was obtained for the large gas phase molecular ions. The results show that an abundance of the product ions from the peptides was mainly observed at 6.1 µm, corresponding to the amide I band; these predominated due to contributions from the C = O stretching vibration of the peptide backbone. For the oligosaccharides, the intensity of the fragment ions gradually increased on increasing the wavelength from 8.5 µm. The IR spectra peaked at a wavelength of around 9.1 µm.