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

March 01, 2016 By:
  • Cabrera G
  • Salazar V
  • Montesino R
  • Tambara Y
  • Struwe WB
  • Leon E
  • Harvey DJ
  • Lesur A
  • Rincon M
  • Domon B
  • Mendez M
  • Portela M
  • Gonzalez-Hernandez A
  • Triguero A
  • Duran R
  • Lundberg U
  • Vonasek E
  • Gonzalez LJ.

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 alpha(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 alpha(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.

2016 Mar. Glycobiology.26(3):230-50. Epub 2015 Nov 3.
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