title: Orbitrap mass spectrometry characterization of hybrid chondroitin/dermatan sulfate hexasaccharide domains expressed in brain.
abstract: In the central nervous system, chondroitin/dermatan sulfate (CS/DS) glycosaminoglycans (GAGs) modulate neurotrophic effects and glial cell maturation during brain development. Previous reports revealed that GAG composition could be responsible for CS/DS activities in brain. In this work, for the structural characterization of DS- and CS-rich domains in hybrid GAG chains extracted from neural tissue, we have developed an advanced approach based on high-resolution mass spectrometry (MS) using nanoelectrospray ionization Orbitrap in the negative ion mode. Our high-resolution MS and multistage MS approach was developed and applied to hexasaccharides obtained from 4- and 14-week-old mouse brains by GAG digestion with chondroitin B and in parallel with AC I lyase. The expression of DS- and CS-rich domains in the two tissues was assessed comparatively. The analyses indicated an age-related structural variability of the CS/DS motifs. The older brain was found to contain more structures and a higher sulfation of DS-rich regions, whereas the younger brain was found to be characterized by a higher sulfation of CS-rich regions. By multistage MS using collision-induced dissociation, we also demonstrated the incidence in mouse brain of an atypical [4,5-Δ-GlcAGalNAc(IdoAGalNAc)2], presenting a bisulfated CS disaccharide formed by 3-O-sulfate-4,5-Δ-GlcA and 6-O-sulfate-GalNAc moieties.
authors.affiliation: Mass Spectrometry Laboratory, National Institute for Research and Development in Electrochemistry and Condensed Matter, RO-300224 Timisoara, Romania; Faculty of Physics, West University of Timisoara, RO-300223 Timisoara, Romania.
authors.forename: Adrian C
authors.initials: AC
authors.lastname: Robu
authors.affiliation: Mass Spectrometry Laboratory, National Institute for Research and Development in Electrochemistry and Condensed Matter, RO-300224 Timisoara, Romania; Faculty of Physics, West University of Timisoara, RO-300223 Timisoara, Romania.
authors.forename: Laurentiu
authors.initials: L
authors.lastname: Popescu
authors.affiliation: Department of Molecular Cell Biology, Institute of Biochemistry of the Romanian Academy, RO-060031 Bucharest, Romania.
authors.forename: Cristian V A
authors.initials: CV
authors.lastname: Munteanu
authors.affiliation: Institute for Physiological Chemistry and Pathobiochemistry, University of Münster, D-49149 Münster, Germany.
authors.forename: Daniela G
authors.initials: DG
authors.lastname: Seidler
authors.affiliation: Mass Spectrometry Laboratory, National Institute for Research and Development in Electrochemistry and Condensed Matter, RO-300224 Timisoara, Romania; Department of Chemical and Biological Sciences, "Aurel Vlaicu" University of Arad, RO-310130 Arad, Romania. Electronic address: alina.zamfir@uav.ro.
authors.forename: Alina D
authors.initials: AD
authors.lastname: Zamfir
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D001923:Brain Chemistry / Q000502:physiology; D002809:Chondroitin Sulfates / Q000096:biosynthesis* / Q000737:chemistry; D003871:Dermatan Sulfate / Q000096:biosynthesis* / Q000737:chemistry; D013058:Mass Spectrometry / Q000379:methods*; D051379:Mice; D009844:Oligosaccharides / Q000096:biosynthesis* / Q000737:chemistry
chemical_list: D009844:Oligosaccharides; D003871:Dermatan Sulfate; D002809:Chondroitin Sulfates
keywords: Brain chondroitin/dermatan sulfate; Compositional and structural analysis; Electrospray ionization; Oligosaccharides; Orbitrap mass spectrometry; Sulfation sites