title: Sequence determination of sulfated carrageenan-derived oligosaccharides by high-sensitivity negative-ion electrospray tandem mass spectrometry.
abstract: Negative-ion electrospray tandem mass spectrometry with collision-induced dissociation is assessed for sequence determination of multiply sulfated oligosaccharide fragments of carrageenan obtained from partial depolymerization of the polysaccharides by either enzymatic digestion or mild acid hydrolysis. Carrageenan oligosaccharides with homogeneous disaccharide compositions were used to establish their fragmentation pattern, which was then applied to sequence determination of unusual oligosaccharides with either "hybrid" biose compositions or odd-numbered residues. As sulfate groups are labile, sulfate loss during collision-induced association was prevented by sodium adduction. The product ion spectra of [M - Na]- (where M represents the sodium salt of oligosaccharides) feature an extensive series of B- and C-type glycosidic cleavages, whereas the Y-type cleavage occurs mainly at the sulfated residues. The assignment of reducing or nonreducing terminal fragments was assisted by oligosaccharide reduction and the product ion spectra of the derived alditols. Due to the anionic nature of the sulfate present, high-sensitivity detection (1-5 pmol, using a hexasaccharide as an example) was obtained.
authors.affiliation: Institute of Marine Drug and Food, Ocean University of China, Qingdao, Shandong 266003, China.
authors.forename: Guangli
authors.initials: G
authors.lastname: Yu
authors.forename: Xia
authors.initials: X
authors.lastname: Zhao
authors.forename: Bo
authors.initials: B
authors.lastname: Yang
authors.forename: Sumei
authors.initials: S
authors.lastname: Ren
authors.forename: Huashi
authors.initials: H
authors.lastname: Guan
authors.forename: Yibing
authors.initials: Y
authors.lastname: Zhang
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Lawson
authors.forename: Wengang
authors.initials: W
authors.lastname: Chai
mesh_terms: D002240:Carbohydrate Sequence; D002351:Carrageenan / Q000737:chemistry*; D004187:Disaccharides / Q000032:analysis / Q000737:chemistry; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000032:analysis* / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization; D013431:Sulfates / Q000737:chemistry*; D053719:Tandem Mass Spectrometry
chemical_list: D004187:Disaccharides; D009844:Oligosaccharides; D013431:Sulfates; D002351:Carrageenan