title: Ss40: the zinc endopeptidase secreted by infective larvae of Strongyloides stercoralis.
abstract: Infective larvae of a pathogenic nematode of humans, Strongyloides stercoralis, release a potent zinc endopeptidase activity which has a broad substrate specificity for constituents of extracellular dermal matrix, including elastin. Specific inhibitors of zinc endopeptidases prevent the penetration of mammalian skin by S. stercoralis larvae. We now report the molecular size and isoelectric point of the S. stercoralis zinc endopeptidase at 40 kDa, pI 5 by zymogram analysis. The activity was not influenced by incubation with beta-mercaptoethanol at 22 degrees C, but was inactivated by incubation at 100 degrees C for 2 min. The enzyme, which we term Ss40, is immunogenic and stimulates humoral IgG antibodies during infection of humans; the activity was immunoprecipitable from ES with pooled infection sera. In addition, a HPLC-enriched Ss40 preparation stimulated the release of histamine from peripheral blood leukocytes of S. stercoralis-infected persons, suggesting that Ss40 is allergenic in humans.
authors.affiliation: Laboratory of Parasitic Diseases, National Institute of Allergy & Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892.
authors.forename: P J
authors.initials: PJ
authors.lastname: Brindley
authors.forename: A A
authors.initials: AA
authors.lastname: Gam
authors.forename: J H
authors.initials: JH
authors.lastname: McKerrow
authors.forename: F A
authors.initials: FA
authors.lastname: Neva
mesh_terms: D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood*; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D010450:Endopeptidases / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D006636:Histamine Release; D006801:Humans; D007814:Larva / Q000201:enzymology / Q000276:immunology; D008623:Mercaptoethanol / Q000494:pharmacology; D011233:Precipitin Tests; D017171:Strongyloides stercoralis / Q000201:enzymology* / Q000276:immunology
chemical_list: D000909:Antibodies, Helminth; D008623:Mercaptoethanol; D010450:Endopeptidases