IPSE/alpha-1, a major secretory glycoprotein antigen from schistosome eggs, expresses the Lewis X motif on core-difucosylated N-glycans.
Schistosomes are parasitic flatworms that infect millions of people in (sub)tropical areas around the world. Glycoconjugates of schistosomes play a critical role in the interaction of the different developmental stages of the parasite with the host. In particular, glycosylated components of the eggs produced by the adult worm pairs living in the bloodstream are strongly immunogenic. We have investigated the glycosylation of interleukin-4-inducing factor from schistosome eggs (IPSE/alpha-1), a major secretory egg antigen from Schistosoma mansoni that triggers interleukin-4 production in human basophils, by MS analysis of tryptic glycopeptides. Nanoscale LC-MS(/MS) and MALDI-TOF(/TOF)-MS studies combined with enzymatic degradations showed that monomeric IPSE/alpha-1 contains two N-glycosylation sites, which are each occupied for a large proportion with core-difucosylated diantennary glycans that carry one or more Lewis X motifs. Lewis X has been reported as a major immunogenic glycan element of schistosomes. This is the first report both on the expression of Lewis X on a specific schistosome egg protein and on a protein-specific glycosylation analysis of schistosome eggs.
Wuhrer
Manfred
M
Department of Parasitology, Center of Infectious Diseases, Leiden University Medical Center, The Netherlands. m.wuhrer@lumc.nl
Balog
Crina I A
CI
Catalina
M I
MI
Jones
Frances M
FM
Schramm
Gabriele
G
Haas
Helmut
H
Doenhoff
Michael J
MJ
Dunne
David W
DW
Deelder
André M
AM
Hokke
Cornelis H
CH
D000595:Amino Acid Sequence; D000818:Animals; D000947:Antigens, Helminth / Q000737:chemistry* / Q000378:metabolism; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D004527:Egg Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D005643:Fucose / Q000737:chemistry / Q000378:metabolism; D006023:Glycoproteins / Q000737:chemistry* / Q000378:metabolism; D015801:Helminth Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010063:Ovum / Q000276:immunology*; D011134:Polysaccharides / Q000737:chemistry* / Q000378:metabolism; D012550:Schistosoma mansoni / Q000276:immunology*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D000947:Antigens, Helminth; D004527:Egg Proteins; D006023:Glycoproteins; D015801:Helminth Proteins; C474807:IPSE protein, Schistosoma mansoni; D011134:Polysaccharides; D005643:Fucose