title: Molecular cloning and characterisation of a putative aspartate proteinase associated with a gut membrane protein complex from adult Haemonchus contortus.
abstract: A cDNA was isolated from an adult Haemonchus contortus cDNA expression library the deduced amino acid sequence of which showed significant homology to mammalian pepsinogen sequences. The library was screened with antisera raised against Haemonchus galactose-containing glycoprotein complex, a gut membrane protein complex with aspartyl proteinase activity which has shown considerable potential as a protective antigen. The amino acid sequence obtained corresponded very closely in part to the N-terminal amino acid sequences of two polypetides within the complex. The enzyme was shown to be almost exclusively expressed by the blood-feeding parasite stages. The cDNA was expressed in E. coli, and antibody produced to the recombinant protein bound to the luminal surface of the gut in the adult parasite. The proteinase may play a central role in digesting the blood meal and is considered a potential sub-unit vaccine candidate.
authors.affiliation: Moredun Research Institute, Edinburgh, UK.
authors.forename: D
authors.initials: D
authors.lastname: Longbottom
authors.forename: D L
authors.initials: DL
authors.lastname: Redmond
authors.forename: M
authors.initials: M
authors.lastname: Russell
authors.forename: S
authors.initials: S
authors.lastname: Liddell
authors.forename: W D
authors.initials: WD
authors.lastname: Smith
authors.forename: D P
authors.initials: DP
authors.lastname: Knox
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000909:Antibodies, Helminth; D016282:Aspartic Acid Endopeptidases / Q000235:genetics* / Q000276:immunology; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D018509:DNA, Helminth / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D006189:Haemonchus / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development; D015801:Helminth Proteins / Q000235:genetics / Q000276:immunology; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000276:immunology; D008969:Molecular Sequence Data; D010435:Pepsinogens / Q000235:genetics; D017386:Sequence Homology, Amino Acid
chemical_list: D000909:Antibodies, Helminth; D018076:DNA, Complementary; D018509:DNA, Helminth; D015801:Helminth Proteins; D008565:Membrane Proteins; D010435:Pepsinogens; D016282:Aspartic Acid Endopeptidases