title: Combining size-exclusion chromatography and fully automated chip-based nanoelectrospray quadrupole time-of-flight tandem mass spectrometry for structural analysis of chondroitin/dermatan sulfate in human decorin.
abstract: Chondroitin/dermatan sulfate (CS/DS) chain of decorin (DCN) from human skin fibroblasts (HSk) was released by reductive β-elimination reaction and digested with chondroitin AC I lyase. Enzymatic hydrolysis mixture of CS/DS chains was separated by size-exclusion chromatography (SEC). Collected octasaccharide fraction was subjected to fully automated chip-based nanoelectrospray (nanoESI) quadrupole time-of-flight (QTOF) MS and tandem MS (MS/MS). MS of human skin fibroblasts DCN CS/DS displayed a high complexity due to the large variety of glycoforms, which under chip-nanoESI MS readily ionized to form multiply charged ions. Except for the regularly tetrasulfated octasaccharide, the investigated fraction contained four additional octasaccharides of atypical sulfation status. Two new oversulfated glycoforms and two undersulfated species were identified. Remarkably, the series of decasaccharides discovered in the same SEC pool was found to encompass a trisulfated and a novel hexasulfated [4,5-Δ-GlcAGalNAc(IdoAGalNAc)⁴] species. MS/MS by collision-induced dissociation (CID) on the [M-4H]⁴ ion corresponding to the previously not reported [4,5-Δ-GlcAGalNAc(IdoAGalNAc)₃](5S) corroborated for a novel motif in which three N-acetylgalactosamine (GalNAc) moieties are monosulfated, 4,5-Δ-GlcA and the first IdoA from the non-reducing end bear one sulfate group each, while the second N-acetylgalactosamine from the reducing end is unsulfated.
authors.affiliation: Department of Chemical and Biological Sciences, Aurel Vlaicu University of Arad, Arad, Romania. alina.zamfir@uav.ro
authors.forename: Alina D
authors.initials: AD
authors.lastname: Zamfir
authors.forename: Corina
authors.initials: C
authors.lastname: Flangea
authors.forename: Eugen
authors.initials: E
authors.lastname: Sisu
authors.forename: Daniela G
authors.initials: DG
authors.lastname: Seidler
authors.forename: Jasna
authors.initials: J
authors.lastname: Peter-Katalinić
mesh_terms: D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002809:Chondroitin Sulfates / Q000737:chemistry* / Q000378:metabolism; D002850:Chromatography, Gel / Q000379:methods*; D058575:Decorin / Q000737:chemistry* / Q000378:metabolism; D003871:Dermatan Sulfate / Q000737:chemistry* / Q000378:metabolism; D005347:Fibroblasts / Q000737:chemistry / Q000166:cytology / Q000378:metabolism; D006801:Humans; D046208:Microchip Analytical Procedures / Q000379:methods*; D008969:Molecular Sequence Data; D012867:Skin / Q000737:chemistry / Q000166:cytology / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: C546878:DCN protein, human; D058575:Decorin; D003871:Dermatan Sulfate; D002809:Chondroitin Sulfates