title: Purification of a 44 kilodalton protease which mediates the ecdysis of infective Haemonchus contortus larvae.
abstract: We have characterized and purified a parasite protease which mediates the ecdysis of Haemonchus contortus, and at least several other ruminant trichostrongyles. The protease, with an apparent approximate molecular weight of 44,000, is a zinc metalloprotein which hydrolyzes several large protein substrates in in vitro assays. In vivo and in biological assays on isolated second molt cuticles this protease hydrolyzes a specific circular region of the second stage cuticle which results in removal of a cuticular cap, providing a rapid and synchronous method for the escape of infective larvae during the transition from free-living to parasitic environments.
authors.affiliation: United States Department of Agriculture, Livestock and Poultry Sciences Institute, Beltsville, MD 20705.
authors.forename: H R
authors.initials: HR
authors.lastname: Gamble
authors.forename: J P
authors.initials: JP
authors.lastname: Purcell
authors.forename: R H
authors.initials: RH
authors.lastname: Fetterer
mesh_terms: D000818:Animals; D001391:Azo Compounds / Q000378:metabolism; D002499:Centrifugation, Density Gradient; D002851:Chromatography, High Pressure Liquid; D003094:Collagen / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D006189:Haemonchus / Q000201:enzymology* / Q000254:growth & development; D007814:Larva / Q000201:enzymology / Q000254:growth & development; D008666:Metalloendopeptidases / Q000302:isolation & purification / Q000378:metabolism; D008970:Molecular Weight; D010447:Peptide Hydrolases / Q000302:isolation & purification* / Q000378:metabolism; D014251:Trichostrongyloidea / Q000201:enzymology*
chemical_list: D001391:Azo Compounds; C028470:Azocoll; D003094:Collagen; D010447:Peptide Hydrolases; D008666:Metalloendopeptidases