ABSTRACTSchistosomiasis affects over 200 million people worldwide, with over 200,000 deaths annually. Currently, praziquantel is the only drug available against schistosomiasis. We report here thatSchistosoma mansonifarnesyl diphosphate synthase (SmFPPS) and geranylgeranyl diphosphate synthase (SmGGPPS) are potential drug targets for the treatment of schistosomiasis. We expressed active, recombinantSmFPPS andSmGGPPS for subsequent kinetic characterization and testing against a variety of bisphosphonate inhibitors. RecombinantSmFPPS was found to be a soluble 44.2-kDa protein, whileSmGGPPS was a soluble 38.3-kDa protein. Characterization of the substrate utilization of the two enzymes indicates that they have overlapping substrate specificities. AgainstSmFPPS, several bisphosphonates had 50% inhibitory concentrations (IC50s) in the low micromolar to nanomolar range; these inhibitors had significantly less activity againstSmGGPPS. Several lipophilic bisphosphonates were active againstex vivoadult worms, with worm death occurring over 4 to 6 days. These results indicate that FPPS and GGPPS could be of interest in the context of the emerging resistance to praziquantel in schistosomiasis therapy.
Characterization of G-Quadruplex Motifs in espB, espK, and cyp51 Genes of Mycobacterium tuberculosis as Potential Drug Targets
