Editor: Albert Descoteaux
Kinetic characterization and gene expression of adenosine deaminase in intact trophozoites of Trichomonas vaginalis
Article first published online: 26 APR 2011
© 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved
FEMS Microbiology Letters
Volume 319, Issue 2, pages 115–124, June 2011
How to Cite
Weizenmann, M., Frasson, A. P., de Barros, M. P., Vieira, P. d. B., Rosemberg, D. B., De Carli, G. A., Bogo, M. R., Bonan, C. D. and Tasca, T. (2011), Kinetic characterization and gene expression of adenosine deaminase in intact trophozoites of Trichomonas vaginalis. FEMS Microbiology Letters, 319: 115–124. doi: 10.1111/j.1574-6968.2011.02283.x
- Issue published online: 17 MAY 2011
- Article first published online: 26 APR 2011
- Accepted manuscript online: 8 APR 2011 10:37AM EST
- Received 19 February 2011; accepted 11 March 2011., Final version published online 26 April 2011.
- Trichomonas vaginalis;
- adenosine deaminase;
- intact trophozoites;
Trichomonas vaginalis is a parasite that resides in the human urogenital tract and causes trichomonosis, the most prevalent nonviral sexually transmitted disease. Nucleoside triphosphate diphosphohydrolase (NTPDase), which hydrolyzes extracellular di- and triphosphate nucleotides, and ecto-5′-nucleotidase, which hydrolyzes AMP, have been characterized in T. vaginalis. The aim of this study was to characterize the adenosine deaminase (ADA) activity in intact trophozoites of T. vaginalis. A strong inhibition in adenosine deamination was observed in the presence of calcium and magnesium, which was prevented by EDTA. The apparent KM value for adenosine was 1.13 ± 0.07 mM. The calculated Vmax was 2.61 ± 0.054 nmol NH3 min−1 mg−1 protein. Adenosine deamination was inhibited in the presence of erythro-9-(2-hydroxy-3-nonyl)adenine. Semi-quantitative reverse transcriptase-PCR experiments were performed and both ADA-related genes ada(125) and ada(231) mRNA were expressed, although ada(231) in higher quantity when compared with the ada(125) : α-tubulin ratio. Furthermore, a phylogenetic analysis showed that the T. vaginalis sequences formed a clade with Entamoeba histolytica and Dictyostelium discoideum sequences, and it strongly suggests homologous functions in the T. vaginalis genome. The presence of ADA activity in T. vaginalis may be important to modulate the adenosine/inosine levels during infection and, consequently, to maintain the anti-inflammatory properties through different nucleoside-signalling mechanisms.