Structural characterization and biological implications of sulfated N-glycans in a serine protease from the neotropical moth Hylesia metabus (Cramer [1775]) (Lepidoptera: Saturniidae)

• Published in: Glycobiology (Oxford) Vol. 26; no. 3; pp. 230 - 250
• Main Authors: Cabrera, Gleysin, Salazar, Víctor, Montesino, Raquel, Támbara, Yanet, Struwe, Weston B, Leon, Evelyn, Harvey, David J, Lesur, Antoine, Rincón, Mónica, Domon, Bruno, Méndez, Milagros, Portela, Madelón, González-Hernández, Annia, Triguero, Ada, Durán, Rosario, Lundberg, Ulf, Vonasek, Eva, González, Luis Javier
• Format: Journal Article
• Language: English
• Published: England Oxford University Press (OUP) 01.03.2016
• Subjects: Animals; Glycosylation; Life Sciences; Moths; Moths - enzymology; Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase; Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase - chemistry; Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase - metabolism; Polysaccharides; Polysaccharides - chemistry; Polysaccharides - metabolism; Serine Proteases; Serine Proteases - chemistry; Serine Proteases - metabolism; Sulfates; Sulfates - chemistry; Sulfates - metabolism; sulfated N-glycans; Hylesia metabus; insects; lepidopterism; serine protease
• ISSN: 0959-6658; 1460-2423
• DOI: 10.1093/glycob/cwv096

Contact with the urticating setae from the abdomen of adult females of the neo-tropical moth Hylesia metabus gives rise to an urticating dermatitis, characterized by intense pruritus, generalized malaise and occasionally ocular lesions (lepidopterism). The setae contain a pro-inflammatory glycosylated protease homologous to other S1A serine proteases of insects. Deglycosylation with PNGase F in the presence of a buffer prepared with 40% H2 (18)O allowed the assignment of an N-glycosylation site. Five main paucimannosidic N-glycans were identified, three of which were exclusively α(1-6)-fucosylated at the proximal GlcNAc. A considerable portion of these N-glycans are anionic species sulfated on either the 4- or the 6-position of the α(1-6)-mannose residue of the core. The application of chemically and enzymatically modified variants of the toxin in an animal model in guinea pigs showed that the pro-inflammatory and immunological reactions, e.g. disseminated fibrin deposition and activation of neutrophils, are due to the presence of sulfate-linked groups and not on disulfide bonds, as demonstrated by the reduction and S-alkylation of the toxin. On the other hand, the hemorrhagic vascular lesions observed are attributed to the proteolytic activity of the toxin. Thus, N-glycan sulfation may constitute a defense mechanism against predators.