Molecular and Biochemical Parasitology 76 (1996) 339-343 Short communication Cloning of an Fe-superoxide dismutase gene homologue from zyxwvutsrq Trypanosoma cruzil Nigel J. Temperton *, Shane R. Wilkinson, John M. Kelly Department of M edical Parasitology , London School of Hygiene and Tropical Medicine, Keppel Street, London W CIE 7HT, UK Received 8 November 1995; accepted 15 December 1995 Keywords: Trypanosoma cruzi; Iron superoxide dismutase; Oxidative stress Development of new chemotherapeutic agents against Chagas’ disease is a major WHO objective [I]. Drugs currently in use, such as nifurtimox, often have serious side effects and can fail to eradicate parasitemia [2]. The trypanocidal effects of nifurtimox are thought to be mediated through the generation of nitro-radicals which promote the formation of toxic oxygen metabolites within the parasite [3,4]. Oxidative stress resulting from the generation of the superoxide radical has also been implicated as a mechanism of action of gentian violet, an agent employed to prevent transmission of Chagas’ disease by blood transfu- sion [5,6]. Thus, identification and functional analysis of Try panosoma cruzi enzymes involved in antioxidant defence could be of importance in the context of improved chemotherapeutic ap- proaches. Trypanosomatids are thought to be devoid of catalase and glutathione peroxidase [7], and it has * Corresponding author. Tel.: f44 171 9272399; Fax: +44 171 6368739; E-mail: n.temperton@lshtm.ac.uk ’ Nucleotide sequence data reported in this paper are avail- able in the GenBank database with accession number U39401. been suggested that the trypanothione system plays a crucial role in maintaining an intracellular reducing environment. Protection against hydro- gen peroxide has been proposed to involve a trypanothione-dependent peroxidase [8- lo], al- though this activity has not been detected in zyxwvutsrqp T. cruzi [ll]. The presence of superoxide dismutase (SOD) has been detected in T. cruzi [12]. This enzyme is a central component in oxidative de- fence in most organisms and functions to remove excess superoxide radicals via dismutation to oxy- gen and hydrogen peroxide [13]. Three distinct SOD activities, Fe, Mn and Cu/Zn have been reported. The Fe-containing SOD, which is found in prokaryotes and some plants, appears to be the enzyme activity normally associated with the try- panosomatids [14]. As a first step towards identi- fying components of the oxidative defence system in T. cruzi, we report here the cloning and initial characterisation of an Fe-SOD gene homologue. The primers FeSOD 1 (S-GGGGAATTCT- CAAAGTTGTCGTTCCACG) and FeSOD2 (S- GGGGGATCCAAGCACCATCAGGGGTATG-I GACG) were used in a PCR reaction (96°C for 45 s, 47°C for 1 min, 72°C for 1 min. with 35 cycles) 0166-6851/96/$15.00 0 1996 Elsevier Science Ireland Ltd. All rights reserved SSDI 0166-6851(95)02553-P