Identification and characterization of keyhole limpet hemocyanin N-glycans mediating cross-reactivity with Schistosoma mansoni.
Keyhole limpet hemocyanin (KLH) of the mollusc Megathura crenulata is known to serologically cross-react with Schistosoma mansoni glycoconjugates in a carbohydrate-dependent manner. To elucidate the structural basis for this cross-reactivity, KLH glycans were released from tryptic glycopeptides and fluorescently labeled. Cross-reacting glycans were identified using a polyclonal antiserum reacting with soluble S. mansoni egg antigens, isolated by a three-dimensional fractionation scheme and analyzed by different mass spectrometric techniques as well as linkage analysis and exoglycosidase treatment. The results revealed that cross-reacting species comprise approximately 4.5% of released glycans. They all represent novel types of N-glycans with a Fuc(alpha1-3)GalNAc(beta1-4)[Fuc(alpha1-3)]GlcNAc motif, which is known to occur also in schistosomal glycoconjugates. The tetrasaccharide unit is attached to the 3-linked antenna of a trimannosyl core, which can be further decorated by galactosyl residues, a xylose residue in 2-position of the central mannose and/or a fucose at the innermost N-acetylglucosamine. This study provides for the first time detailed structural data on the KLH carbohydrate entities responsible for cross-reactivity with glycoconjugates from S. mansoni.
Geyer
Hildegard
H
Institute of Biochemistry, Faculty of Medicine, University of Giessen, Friedrichstrasse 24, D-35392 Giessen, Germany.
Wuhrer
Manfred
M
Resemann
Anja
A
Geyer
Rudolf
R
D000818:Animals; D000918:Antibody Specificity; D000947:Antigens, Helminth / Q000737:chemistry* / Q000276:immunology; D005456:Fluorescent Dyes; D005632:Fructose / Q000032:analysis; D005643:Fucose / Q000032:analysis; D005690:Galactose / Q000032:analysis; D006433:Hemocyanins / Q000737:chemistry* / Q000276:immunology*; D008358:Mannose / Q000032:analysis; D015394:Molecular Structure; D011134:Polysaccharides / Q000737:chemistry* / Q000276:immunology* / Q000302:isolation & purification; D012550:Schistosoma mansoni / Q000276:immunology*; D012699:Serology; D021241:Spectrometry, Mass, Electrospray Ionization; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014357:Trypsin / Q000378:metabolism; D014994:Xylose / Q000032:analysis
D000947:Antigens, Helminth; D005456:Fluorescent Dyes; D011134:Polysaccharides; D005643:Fucose; D005632:Fructose; D006433:Hemocyanins; D014994:Xylose; D014357:Trypsin; C032808:keyhole-limpet hemocyanin; D008358:Mannose; D005690:Galactose