N-glycosylation is a physiologically vital post-translational modification of proteins in eukaryotic organisms. Initial work on Haemonchus contortus - a blood-sucking nematode of ruminants with a broad geographical distribution - has shown that this parasite harbors N-glycans with exclusive chitobiose modifications. Besides, several immunogenic proteins (e.g., amino- and metallo-peptidases) are known to be N-glycosylated in adult worms. However, an informative atlas of N-glycosylation in H. contortus is not yet available. Herein, we report 291 N-glycosylated proteins with a total of 425 modification sites in the parasite. Among them, many peptidase families (e.g., peptidase C1 and M1) including potential vaccine targets were enriched. Notably, the glycan-rich conjugates are distributed primarily in the intestine and gonads of adult worms, and consequently hidden from the host's immune system. Collectively, these data provide a comprehensive atlas of N-glycosylation in a prevalent parasitic nematode while underlining its significance for infection, immunity and prevention.
Keywords: Con A, concanavalin A; Fuc, fucose; Gal, galactose; Gal-Fuc, galactosylated fucose; GalNAc, N-acetylgalactosamine; GlcNAc, N-acetylglucosamine; Glycopeptide; HILIC, hydrophilic interaction chromatography; Haemonchus contortus; LC-MS/MS, liquid chromatography-tandem mass spectrometry; MALDI-ToF MS, matrix-assisted laser desorption ionization-time of flight mass spectrometry; Man, mannose; Mass spectrometry; N-glycan; N-glycosylation; OST, oligosaccharyltransferase; PNGase A/F, peptide-N-glycosidase A/F.
© 2021 The Author(s).