Structural investigation of chondroitin/dermatan sulfate oligosaccharides from human skin fibroblast decorin

• Published in: Glycobiology (Oxford) Vol. 13; no. 11; pp. 733 - 742
• Main Authors: Zamfir, Alina, Seidler, Daniela G., Kresse, Hans, Peter-Katalinić, Jasna
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01-11-2003; Oxford Publishing Limited (England)
• Subjects: capillary electrophoresis; chondroitin sulfate; Chondroitin Sulfates - chemistry; Chondroitin Sulfates - metabolism; CID; collision-induced dissociation; Decorin; dermatan sulfate; Dermatan Sulfate - chemistry; Dermatan Sulfate - metabolism; DS oligosaccharides; Electrophoresis, Capillary - methods; electrospray ionization mass spectrometry; ESI QTOF CID-VE mass spectrometry; ESI-MS; Extracellular Matrix Proteins; FGF; fibroblast growth factor; Fibroblast Growth Factor 2 - metabolism; Fibroblasts - chemistry; GAG; GlcA; glucuronic acid; glycosaminoglycan; Humans; IdoA; iduronic acid; mass spectrometry; Mass Spectrometry - methods; MS/MS; oversulfation; Proteoglycans - chemistry; QTOF; quadrupole time-of-flight; Skin - chemistry; Spectrometry, Mass, Electrospray Ionization - methods; tandem mass spectrometry; TIC; total ion chromatogram; variable energy
• ISSN: 0959-6658; 1460-2423
• DOI: 10.1093/glycob/cwg086

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, Δ-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.