title: Towards GAG glycomics: analysis of highly sulfated heparins by MALDI-TOF mass spectrometry.
abstract: Glycomics is a developing field that provides structural information on complex populations of glycans isolated from tissues, cells and organs. Strategies employing matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) are central to glycomic analysis. Current MALDI-based glycomic strategies are capable of efficiently analyzing glycoprotein and glycosphingolipid glycomes but little attention has been paid to devising glycomic methodologies suited to the analysis of glycosaminoglycan (GAG) polysaccharides which pose special problems for MALDI analysis because of their high level of sulfation and large size. In this paper, we describe MALDI strategies that have been optimized for the analysis of highly sulfated GAG-derived oligosaccharides. A crystalline matrix norharmane, as well as an ionic liquid 1-methylimidazolium alpha-cyano-4-hydroxycinnamate (ImCHCA), have been used for the analysis of heparin di-, tetra-, hexa- and decasaccharides carrying from 2 to 13 sulfate groups. Information about the maximum number of sulfate groups is obtained using the ionic liquid whereas MALDI-TOF/TOF MS/MS experiments using norharmane allowed the determination of the nature of the glycosidic backbone, and more precise information about the presence and the position in the sequence of N-acetylated residues.
authors.affiliation: Division of Molecular Biosciences, Imperial College, London SW7 2AZ, UK.
authors.forename: Bérangère
authors.initials: B
authors.lastname: Tissot
authors.forename: Nijole
authors.initials: N
authors.lastname: Gasiunas
authors.forename: Andrew K
authors.initials: AK
authors.lastname: Powell
authors.forename: Yassir
authors.initials: Y
authors.lastname: Ahmed
authors.forename: Zheng-liang
authors.initials: ZL
authors.lastname: Zhi
authors.forename: Stuart M
authors.initials: SM
authors.lastname: Haslam
authors.forename: Howard R
authors.initials: HR
authors.lastname: Morris
authors.forename: Jeremy E
authors.initials: JE
authors.lastname: Turnbull
authors.forename: John T
authors.initials: JT
authors.lastname: Gallagher
authors.forename: Anne
authors.initials: A
authors.lastname: Dell
mesh_terms: D000818:Animals; D002417:Cattle; D003373:Coumaric Acids / Q000737:chemistry; D003460:Crystallization; D006023:Glycoproteins / Q000737:chemistry; D006025:Glycosaminoglycans / Q000737:chemistry*; D006027:Glycosides / Q000737:chemistry; D006493:Heparin / Q000737:chemistry; D007477:Ions; D013058:Mass Spectrometry / Q000379:methods; D008956:Models, Chemical; D009844:Oligosaccharides / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013107:Sphingolipids / Q000737:chemistry
chemical_list: D003373:Coumaric Acids; D006023:Glycoproteins; D006025:Glycosaminoglycans; D006027:Glycosides; D007477:Ions; D009844:Oligosaccharides; D011134:Polysaccharides; D013107:Sphingolipids; D006493:Heparin