Characterization of Leishmania chagasi DNA Topoisomerase II: a Potential Chemotherapeutic Target

Abstract

DNA topoisomerase II (topo II), an enzyme essential for cellular replication, is an eminent target for antimicrobial therapy against Leishmania chagasi, the major cause of visceral leishmaniasis in Latin America. The complete L. chagasi (Lch) TOP2 gene, encoding L. chagasi topo II, was isolated from genomic DNA using the polymerase chain reaction. The LchTOP2 gene revealed an open reading frame (ORF) of 3,711 base pairs predicting a protein with 1,236 amino acids and an estimated molecular weight of 140 kDA. The L. chagasi topo II sequence had high identity with the L. donovani topo II (98.8%) and L. infantum topo II (98.7%), followed by Crithidia fasciculata topo II (84.4%), Trypanosoma cruzi topo II (67.6%) and Trypanosoma brucei topo II (66.6%). Lch topo II had low identity with the human homologs htopo II alpha (26.3%) and htopo II beta (26.4%). Differences between L. chagasi TOP2 and human TOP2 genes suggest that leishmanial topo II is a potential target for the development of new antileishmanial agents.

Trypanosomatids topoisomerase re-visited. New structural findings and role in drug discovery

“…Only one mtTop II, localized primarily to the antipodal sites of the kinetoplast ( Melendy et al, 1988 ), is predicted after the analysis of the genome sequence of several trypanosomatids ( Strauss and Wang, 1990; Fragoso and Goldenberg, 1992; Das et al, 2001; Hanke et al, 2003; De Sousa et al, 2003 ). In addition, two other Top II enzymes, which are encoded by the tandemly-linked single-copy genes Top II α and Top II β, were found in the chromosome 11 of T. brucei ( Kulikowicz and Shapiro, 2006 ).…”

“…Top IIA activity has been purified from several trypanosomatids and some of the corresponding coding genes have been cloned from Crithidia fasciculata ( Shlomai and Zadok, 1983; Melendy et al, 1988; Melendy and Ray, 1989; Pasion et al, 1992; Hines and Ray, 1997 ), T. brucei ( Strauss and Wang, 1990; Wang and Englund, 2001; Kulikowicz and Shapiro, 2006 ), T. cruzi ( Douc-Rasy et al, 1986; Fragoso et al, 1998 ), Trypanosoma equiperdum ( Shapiro, 1994 ), L. donovani ( Chakraborty and Majumder, 1987, 1991; Das et al, 2001 ), Leishmania chagasi ( De Sousa et al, 2003 ) and L. infantum ( Hanke et al, 2003 ).…”