Analysis of keratan sulfate oligosaccharides by electrospray ionization tandem mass spectrometry.
Keratan sulfate (KS) is a glycosaminoglycan consisting of repeating disaccharide units composed of alternating residues of d-galactose and N-acetyl-d-glucosamine linked beta-(1-4) and beta-(1-3), respectively. In this study, electrospray ionization tandem mass spectrometry (ESI-MS/MS) was employed to identify keratan sulfate oligosaccharides. Two nonsulfated disaccharide isomers and two monosulfated disaccharide isomers were distinguished through MS/MS. In MS(1) spectra of multiply sulfated KS oligosaccharides, the charge state of the most abundant molecular ion equals the number of sulfates. Subsequent MS(2) and MS(3) spectra of mono-, di-, tri-, and tetrasulfated KS oligosaccharides and sialylated tetrasaccharides reveal diagnostic ions that can be used as fingerprint maps to identify unknown KS oligosaccharides. Based on the pattern of fragment ions, the compositions of an oligosaccharide mixture from shark cartilage KS and of two enzyme digests of bovine corneal KS were determined directly, without prior isolation of individual oligosaccharides by HPLC or other methods.
Zhang
Yuntao
Y
Division of Biology, Kansas State University, Manhattan, KS 66506, USA. ytz@ksu.edu
Kariya
Yutaka
Y
Conrad
Abigail H
AH
Tasheva
Elena S
ES
Conrad
Gary W
GW
D000117:Acetylglucosamine / Q000032:analysis; D000818:Animals; D002240:Carbohydrate Sequence; D002417:Cattle; D003315:Cornea / Q000737:chemistry; D005690:Galactose / Q000032:analysis; D007536:Isomerism; D007632:Keratan Sulfate / Q000032:analysis* / Q000737:chemistry; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000032:analysis* / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
D009844:Oligosaccharides; D007632:Keratan Sulfate; D000117:Acetylglucosamine; D005690:Galactose