Journal Article

Electron-Induced Dissociation of Glycosaminoglycan Tetrasaccharides

Aslam, Hammad, Laremore, Tatiana N., Wolff, Jeremy J., Linhardt, Robert J., Amster, I. Jonathan

2008

Overview

Electron detachment dissociation (EDD) Fourier transform mass spectrometry has recently been shown to be a powerful tool for examining the structural features of sulfated glycosaminoglycans (GAGs). The characteristics of GAG fragmentation by EDD include abundant cross-ring fragmentation primarily on hexuronic acid residues, cleavage of all glycosidic bonds, and the formation of even- and odd-electron product ions. GAG dissociation by EDD has been proposed to occur through the formation of an excited species that can undergo direct decomposition or ejects an electron and then undergoes dissociation. In this work, we perform electron-induced dissociation (EID) on singly charged GAGs to identify products that form via direct decomposition by eliminating the pathway of electron detachment. EID of GAG tetrasaccharides produces cleavage of all glycosidic bonds and abundant cross-ring fragmentation primarily on hexuronic acid residues, producing fragmentation similar to EDD of the same molecules, but distinctly different from the products of infrared multiphoton dissociation or collisionally activated decomposition. These results suggest that observed abundant fragmentation of hexuronic acid residues occurs as a result of their increased lability when they undergo electronic excitation. EID fragmentation of GAG tetrasaccharides results in both even- and odd-electron products. EID of heparan sulfate tetrasaccharide epimers produces identical fragmentation, in contrast to EDD, in which the epimers can be distinguished by their fragment ions. These data suggest that for EDD, electron detachment plays a significant role in distinguishing glucuronic acid from iduronic acid. Fragmentation of glycosaminoglycan tetrasaccharide singly charged ions by electron-induced dissociation produces many products similar to those produced by electron detachment dissociation of higher charge states.

• Publisher: Elsevier Inc,Springer-Verlag,Elsevier
• Subject: Analytical Chemistry / Analytical, structural and metabolic biochemistry / Bioinformatics / Biological and medical sciences / Biotechnology / Chemistry / Chemistry and Materials Science / Electrons / Fourier Analysis / Fundamental and applied biological sciences. Psychology / Glucuronic Acid - analysis / Glycosaminoglycans - analysis / Glycosaminoglycans - chemistry / Heparitin Sulfate - chemistry / Hexuronic Acids - chemistry / Iduronic Acid - analysis / Ions - analysis / Ions - chemistry / Isomerism / Lipids / Miscellaneous / Molecular Structure / Oligosaccharides - analysis / Oligosaccharides - chemistry / Organic Chemistry / Other biological molecules / Proteomics / Tandem Mass Spectrometry - methods