title: Schistosomes express two forms of cathepsin D.
abstract: We report here a cDNA and its deduced amino acid sequence encoding a cathepsin D-like, aspartic protease expressed by adult stages of the human blood fluke Schistosoma mansoni. The cDNA encodes a short signal peptide, a pro-enzyme peptide of 37 amino acid residues, and a mature enzyme of 377 residues which has strong homology with mammalian cathepsins D. This aspartic protease, although 84% identical in amino acids of the mature enzyme region to the previously reported cathepsin D from the Asian schistosome S. japonicum, differs remarkably from the S. japonicum enzyme in having a carboxyl terminal extension of 43 amino acid residues. These cathepsins D of schistosomes may play pivotal roles in the degradation of hemoglobin obtained by the parasites from ingested host erythrocytes.
authors.affiliation: Queensland Institute of Medical Research, and Australian Centre for International and Tropical Health and Nutrition, Royal Brisbane Hospital, Herston.
authors.forename: J Y
authors.initials: JY
authors.lastname: Wong
authors.forename: S A
authors.initials: SA
authors.lastname: Harrop
authors.forename: S R
authors.initials: SR
authors.lastname: Day
authors.forename: P J
authors.initials: PJ
authors.lastname: Brindley
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015139:Blotting, Southern; D002402:Cathepsin D / Q000235:genetics*; D018076:DNA, Complementary / Q000235:genetics; D017238:Genes, Helminth; D006801:Humans; D008969:Molecular Sequence Data; D012550:Schistosoma mansoni / Q000201:enzymology*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D018076:DNA, Complementary; D002402:Cathepsin D