Primary structures of Sm31/32 diagnostic proteins of Schistosoma mansoni and their identification as proteases

Expression and partial characterization of a cathepsin B-like enzyme (Sm31) and a proposed ‘haemoglobinase’ (Sm32) from Schistosoma mansoni

“…We had considered it most likely that Sm31 is a h , , 1 . I Study of two Schistosoma mansoni proteins, Sm3l and Sm32 (Barrett et al, 1984), human lysosomal cathepsin B (Chan et al, 1986), S. mansoni Sm31 (Klinkert et al, 1989), chicken calpain (Ohno et al, 1984), Streptococcus pyogenes proteinase (Tai et al, 1976) and S. mansoni Sm32 (Klinkert et al, 1989;El Meanawy et al, 1990), Clostridium histolyticum clostripain (Gilles et al, 1983) and poliovirus 3C proteinase (Argos et al, 1984) are aligned so as to achieve maximal identity ( Figure 6). Cysteine-proteinase-related enzymes found in bacteria are represented by the proteinase of S. pyogenes and clostripain from C. histolyticum.…”

“…Taking advantage of the immunogenic nature of this enzyme, we used human and mouse infection sera to screen a cDNA library prepared from adult Schistosoma mansoni RNA. This led to the isolation of a full-length cDNA clone encoding a 31 kDa protein (Sm3 1), and nucleotide and deduced amino acid sequences confirmed Sm31 as the schistosome counterpart of mammalian lysosomal cathepsin B (Klinkert et al, 1989). During the course of these studies, we isolated a second cDNA sequence encoding a closely migrating protein with an apparent molecular mass of 32 kDa (Sm32).…”

Laboratory diagnosis of Schistosomiasis in areas of low transmission: a review of a line of research

“…The identification and cloning of molecules of diagnostic value as the cathepsin B (Sm31) and the asparraginil endopeptidase legumain (Sm32) (Klinkert et al 1989, Noya et al 1995, allowed their production by genetic engineering (El-Sayed et al 1998) and chemical synthesis . Of them, the peptides of the Sm31 have shown higher antigenicity.…”

Proteomic analysis of adult S. mansoni gut contents

“…Cystatins are tight binding inhibitors of the papain family of cysteine proteases [19] and may inhibit the gut cysteine proteases cathepsins B and L to regulate their activities. Also intriguing was the identification of the catalytically inactive form of the asparaginyl endopeptidase SmAE (legumain or Sm32 [20,21]) in which the active site cysteine is replaced by an asparagine. Apart from this substitution, the other residues constituting enzyme's binding pocket are intact and it is therefore possible that inactive SmAE might compete with the active enzyme for substrates, thus providing post-translational regulation.…”