Molecular Cloning and Expression of Iranian Leishmania major Pteridine Reductase 1

Background: Leishmaniasis is an endemic disease in 88 countries. Reports on Leishmania drug resistance are growing in number. The mechanism of unresponsiveness against glucantime in Iranian cutaneous leishmaniasis has not yet been characterized. To begin the first step in finding an anti-Leishmania chemotherapy, we prepared recombinant L. major PTR1 enzyme and characterized its activity by enzymatic assay. Methods: Leishmania promastigote DNA was extracted and the ptrl gene amplified using specific primers. The PCR product was cloned in pQE30 expression vector, transformed into E.coli and expressed. The recombinant protein was purified, its enzymatic activity was assayed and anti-PTRl antibody prepared in rabbit. Results: The PCR product of ptrl gene was sequenced and deposited in GenBank. The amino acid sequence of Iranian L. major PTR1 was compared with other Leishmania PTR1 and showed some identities and diversities. Purified protein was reacted by anti PTR1 antibody in gel diffusion and western blot assy. Enzyme activity of purified recombinant PTR1 was 38 nmol/min per 0.4 mg of protein and it showed pteridine reduction by PTR1 Conclusion: We cloned and expressed Iranian L. major ptrl gene and assayed its enzymatic activity. This enzyme will be used for further investigation about Leishmania antifolate therapy that is effective against PTR1