Send to

Choose Destination
See comment in PubMed Commons below
Mol Biochem Parasitol. 2008 Aug;160(2):129-37. doi: 10.1016/j.molbiopara.2008.05.001. Epub 2008 May 8.

Identification and characterization of a cathepsin L-like cysteine protease from Gnathostoma spinigerum.

Author information

Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.


Gnathostoma spinigerum is a causative agent of human gnathostomiasis, a common parasitic disease involving skin and visceral organs, especially the central nervous system. In this study, we identified a cDNA encoding a cathepsin L-like cysteine protease (GsCL1) from the lambdaZAP cDNA library of G. spinigerum advanced third-stage larva (aL3) and characterized the biochemical properties of the recombinant enzyme. The cloned cDNA of 1484bp encoded 398 amino acids which contained a typical signal peptide sequence (23 amino acids), a pro-domain (156 amino acids), and a mature domain (219 amino acids) with an approximate molecular weight of 24kDa. The deduced amino acid sequence of GsCL1 gene showed 53-64% identity to cathepsin L proteases of various organisms including a cathepsin L family member (cpl-1) of Caenorhabditis elegans. Recombinant proGsCL1 expressed in Pichia pastoris showed typical biochemical characteristics of cysteine proteases. The expressed enzyme displayed optimal protease activity toward Z-Phe-Arg-AMC substrate at pH 6.0 but not toward Z-Arg-Arg-AMC. The activity was sensitive to cysteine protease inhibitors E-64 and K11777. The preference for large hydrophilic and aromatic residues in the P2 position (I, L, F, W, U, V) was typical of cathepsin L proteases. Mouse anti-GST-proGsCL1 serum showed reactivity with 35-, 38- and 45-kDa proteins in the aL3 extracts. These proteins were shown to localize inside the intestinal cells of aL3.

[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons


    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Support Center