title: Purification of a cathepsin L-like proteinase secreted by adult Fasciola hepatica.
abstract: A cysteine proteinase released in vitro by Fasciola hepatica was purified to homogeneity by Sephacryl S-200 gel filtration chromatography followed by QAE-Sephadex chromatography. The purified enzyme resolves as a single band with an apparent molecular size of 27 kDa on reducing SDS-polyacrylamide gel electrophoresis; however, under non-reducing conditions it migrates as multiple bands, each with enzymatic activity, in the apparent molecular size range 60-90 kDa. The sequence of the first 20 N-terminal amino acids of the enzyme shows considerable homology with cathepsin L-like proteinases. Immunolocalisation studies revealed that the cathepsin L-like proteinase is concentrated within vesicles in the gut epithelial cells of liver fluke.
authors.affiliation: Medical Biology Centre, Queens University Belfast, Northern Ireland, UK.
authors.forename: A M
authors.initials: AM
authors.lastname: Smith
authors.forename: A J
authors.initials: AJ
authors.lastname: Dowd
authors.forename: S
authors.initials: S
authors.lastname: McGonigle
authors.forename: P S
authors.initials: PS
authors.lastname: Keegan
authors.forename: G
authors.initials: G
authors.lastname: Brennan
authors.forename: A
authors.initials: A
authors.lastname: Trudgett
authors.forename: J P
authors.initials: JP
authors.lastname: Dalton
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D056668:Cathepsin L; D002403:Cathepsins / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D002417:Cattle; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D003546:Cysteine Endopeptidases / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D010450:Endopeptidases; D004792:Enzyme Precursors / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D005210:Fasciola hepatica / Q000201:enzymology* / Q000235:genetics; D006801:Humans; D015151:Immunoblotting; D007150:Immunohistochemistry; D008969:Molecular Sequence Data; D051381:Rats; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity
chemical_list: D004792:Enzyme Precursors; D002403:Cathepsins; D010450:Endopeptidases; D003546:Cysteine Endopeptidases; C534281:CTSL protein, human; D056668:Cathepsin L; C534280:Ctsl protein, rat