Biochemical analysis of a potential drug target in the human protozoal pathogen Trichomonas vaginalis
Trichomonas vaginalis carries out unique mode of carbohydrate decarboxylation by an intracellular compartment, hydrogenosome. It was suggested that enzymes exclusively associated with hydrogenosome were responsible for activating metronidazole. This provoked researchers to target hydrogensosomal enzymes such as pyruvate: ferredoxin oxioreductase and ferredoxin, to treat trichomoniasis caused by T. vaginalis. Recent studies have shown alternative pathways responsible for activating metronidazole without the involvement of hydrogenosomal enzymes. This pathway requires the participation of thioredoxin and thioredoxin reductase. These enzymes are essential for T.vaginalis' survival as it is responsible for maintaining cell's redox system, as well as many other cellular processes. Targeting thioredoxin and thioredoxin reductase could be a novel drug target to treat metronidazole-resistant T. vaginalis. In this study, recombinant T. vaginalis TrxR and T. vaginalis Trx were produced to test its activity against known TrxR inhibitor, auranofin, using DTNB assay. Cell lysates of metronidazole susceptible and metronidazole resistant lines were also tested to see its activity against auranofin. Auranofin derivatives that were effective on E. histolytica recombinant TrxR were also tested to compare their effects on T. vaginalis recombinant TrxR. The results showed that auranofin effectively inhibits recombinant TvTrxR. Aurnofin derivatives were also shown to have different effects on inhibiting the activity of recombinant TvTrxR. It is known that auranofin also targets mammalian TrxR. With the degree of different inhibitions observed between auranofin derivatives, it opened the possibility of developing an auranofin derivative that can specifically targets thioredoxin reductase of parasitic protozoan, T. vaginalis.
Molecular biology, Pharmacology, Biochemistry, Pure sciences, Biological sciences, Health and environmental sciences, Biology
Networked Digital Library of Theses and Dissertations