Negative electron transfer dissociation Fourier transform mass spectrometry of glycosaminoglycan carbohydrates

Abstract

Electron transfer through gas-phase ion–ion reactions has led to the widespread application ofelectron-based techniques once only capable in ion trapping mass spectrometers. Although anymass analyzer can, in theory, be coupled to an ion–ion reaction device (typically a 3-D ion trap),some systems of interest exceed the capabilities of most mass spectrometers. This case isparticularly true in the structural characterization of glycosaminoglycan (GAG) oligosaccharides.To adequately characterize highly sulfated GAGs or oligosac charides above the tetrasaccharidelevel, a high-resolution mass analyzer is required. To extend previous efforts on an ion trap massspectrometer, negative electron transfer dissociation coupled with a Fourier transform ioncyclotron resonance mass spectrometer has been applied to increasingly sulfated heparan sulfateand heparin tetrasaccharides as well as a dermatan sulfate octasaccharide. Results similar to thoseobtained by electron detachment dissociation are observed.