Characterization of developmentally-regulated nucleases in promastigotes and amastigotes of Leishmania mexicana.
The parasitic protozoon Leishmania mexicana was examined for the presence of 3'-nucleotidase/nuclease using substrate SDS-PAGE. Two activities were detected: one with an apparent molecular mass of 40 kDa, and a doublet of 29/31 kDa. The two enzymes showed differences in their levels of expression in the two life-cycle stages of parasite examined: the 29/31 kDa doublet was detected at 60-fold higher levels in the pathogenic amastigote stage, but was also expressed by promastigotes, whereas the 40 kDa activity was only detected in promastigotes. Both were capable of hydrolysing a variety of substrates including 3'-AMP and poly(A). However, the 29/31 kDa form showed a broader, unique substrate specificity in that it was also capable of digesting double-stranded RNA and DNA.
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Department of Zoology, University of Glasgow, UK.
D000818:Animals; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D007894:Leishmania mexicana / Q000201:enzymology* / Q000254:growth & development; D051379:Mice; D008808:Mice, Inbred CBA; D008970:Molecular Weight; D009708:Nucleotidases / Q000302:isolation & purification* / Q000378:metabolism; D015800:Protozoan Proteins / Q000302:isolation & purification* / Q000378:metabolism; D013379:Substrate Specificity
D015800:Protozoan Proteins; D009708:Nucleotidases; C040470:3'-nucleotidase