Acta Tropica 100 (2006) 88–95 Characterization of ecto-phosphatase activities of Trypanosoma cruzi: A comparative study between Colombiana and Y strains P.M.L. Dutra a , L.C. Couto b , A.H.C.S. Lopes b , J.R. Meyer-Fernandes c,∗ a Disciplina de Parasitologia, DPL, FCM, UERJ, Rua Prof. Manoel de Abreu 444, 5 ◦ andar, Vila Isabel, Rio de Janeiro, RJ 20550-170, Brazil b Instituto de Microbiologia Prof. Paulo de G´ oes, UFRJ, Ilha do Fund˜ ao, Rio de Janeiro, RJ 21941-590, Brazil c Instituto de Bioqu´ ımica M´ edica, UFRJ, Ilha do Fund˜ ao, Rio de Janeiro, 21941-590 RJ, Brazil Received 9 October 2005; received in revised form 18 April 2006; accepted 19 May 2006 Available online 23 October 2006 Abstract The etiological agent of Chagas disease, Trypanosoma cruzi, is consisted of two phylogenetic lineages. Using live epimastigotes, in this study we have characterized ecto-phosphatase activities of two strains of T. cruzi, one (Y strain) is a member of group T. cruzi I and the other (Colombiana) is a member of group T. cruzi II. About one-third of the total ecto-phosphatase activity from the Y strain was Mg 2+ -dependent, but no such activity was observed with Colombiana. The level of Mg 2+ -independent activity was dramatically different in the two strains, with Colombiana showing more than 15-fold higher activity. Experiments using classical inhibitors of acid phosphatases, as well as inhibitors of phosphotyrosine phosphatase, showed a decrease in these phosphatase activities, with different patterns of inhibition. The Mg 2+ -independent activities of the Colombiana and Y strains decreased inversely with pH, varying from 6.5 to 8.0. On the other hand, the Mg 2+ -dependent activity of the Y strain increased concomitantly with the increase in pH in the same range. © 2006 Elsevier B.V. All rights reserved. Keywords: Ecto-phosphatase activity; Trypanosoma cruzi; Colombiana strain; Y strain 1. Introduction Chagas disease is widespread throughout Latin Amer- ica where nearly 20 million people are infected by Try- panosoma cruzi and 90 million are at risk in endemic areas. A large fraction of these will die a premature death, usually of cardiac complications (Guhl et al., 2005). T. cruzi undergoes a complex life cycle, which allows the adaptation to both intermediate hosts (triatomine insects and mammals, including man). T. cruzi cell differentia- tion gives rise to four morphogenetic forms: epimastig- ∗ Corresponding author. Tel.: +55 21 2562 6781; fax: +55 21 2270 8647. E-mail address: meyer@bioqmed.ufrj.br (J.R. Meyer-Fernandes). ote, metacyclic trypomastigote, amastigote, and blood- stream trypomastigotes. This process is highly regulated and includes significant changes in morphology, bio- chemical and signal transduction pathways, gene expres- sion and structural alterations in the surface molecules of these parasites (De Souza, 2002). Therefore, studies related to the enzymes responsible for the phospho- rylation and dephosphorylation of proteins, which are present on the external surface of these parasites, are extremely important. Ecto-protein kinases have been identified in Leishma- nia major (Sacerdoti-Sierra and Jaffe, 1997) and ecto- phosphatase activities have been characterized in some members of the family Trypanosomatidae, such as Try- panosoma (Fernandes et al., 1997; Meyer-Fernandes et al., 1999) and Leishmania (Glew et al., 1982; Gottlieb 0001-706X/$ – see front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.actatropica.2006.05.014