title: Structural investigation of chondroitin/dermatan sulfate oligosaccharides from human skin fibroblast decorin.
abstract: Hybrid chondroitin/dermatan sulfate (CS/DS) glycosaminoglycan chains, derived from decorin secreted by human skin fibroblasts, were shown to interact with FGF-2, as did oligosaccharides derived therefrom by chondroitin B lyase digestion. In a first attempt to identify the biologically active sequence, a novel protocol for structural analysis of enzyme-resistant oligosaccharides larger than standard trisulfated hexasaccharides was developed. The method bases on capillary electrophoresis (CE) for separating oversulfated species in offline combination with nanoelectrospray ionization quadrupole time-of-flight tandem mass spectrometry (nanoESI-QTOF-MS/MS) in the negative ion mode. Under optimized CE and ESI-MS conditions, up to 12-mer oligosaccharides with different degrees of sulfation were identified. A novel tandem MS protocol (CID-VE) was applied to elucidate the structure of a previously undescribed pentasulfated CS/DS hexasaccharide, Delta-4,5-IdoAGalNAc[GlcAGalNAc]2(5S). In this molecular species, detected as a triply charged ion at m/z 511.38, three sulfates are found in the IdoAGalNAcGlcA moiety offering two structural variants: one containing sulfated IdoA together with a disulfated GalNAc moiety and in the other one both uronic acids, that is, GlcA and IdoA and the amino sugar each carry a sulfate ester group.
authors.affiliation: Institute for Medical Physics and Biophysics, Biomedical Analysis Department, University of Münster, Robert-Koch-Str. 31, D-48149, Münster, Germany.
authors.forename: Alina
authors.initials: A
authors.lastname: Zamfir
authors.forename: Daniela G
authors.initials: DG
authors.lastname: Seidler
authors.forename: Hans
authors.initials: H
authors.lastname: Kresse
authors.forename: Jasna
authors.initials: J
authors.lastname: Peter-Katalinić
mesh_terms: D002809:Chondroitin Sulfates / Q000737:chemistry* / Q000378:metabolism; D058575:Decorin; D003871:Dermatan Sulfate / Q000737:chemistry* / Q000378:metabolism; D019075:Electrophoresis, Capillary / Q000379:methods; D016326:Extracellular Matrix Proteins; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism; D005347:Fibroblasts / Q000737:chemistry*; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods; D011509:Proteoglycans / Q000737:chemistry*; D012867:Skin / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods
chemical_list: C546878:DCN protein, human; D058575:Decorin; D016326:Extracellular Matrix Proteins; D011509:Proteoglycans; D016222:Fibroblast Growth Factor 2; D003871:Dermatan Sulfate; D002809:Chondroitin Sulfates