The Ld Cht1 gene encodes the secretory chitinase of the human pathogen Leishmania donovani

Leishmania donovani promastigotes were shown to release chitinase activity during their growth in vitro. A PCR-based strategy identified a single copy ORF capable of encoding the L. donovani chitinase (Ld Cht1, 1374 bp). Ld Cht1 was shown to be actively transcribed by L. donovani promastigotes using reverse transcription and PCR amplification. The deduced aa sequence of Id Cht1 showed high conservation to known chitinases including the putative active and two substrate binding sites. Antiserum generated against four peptides derived from its deduced aa sequence immunoprecipitated; an approx. 50-kDa in vitro transcription/translation product of Ld Cht1. Further, this antiserum also immunoprecipitated both the native L. donovani 50-kDa Cht1 protein and the native chitinase activity synthesized and released by these parasites. Cumulatively, these data demonstrated that Ld Chtl encoded the chitinase of this important human pathogen. (C) 1998 Elsevier Science B.V.