An NMR Biochemical Assay for Fragment-Based Drug Discovery: Evaluation of an Inhibitor Activity on Spermidine Synthase of Trypanosoma cruzi

Although NMR in fragment-based drug discovery is utilized almost exclusively to evaluate physical binding between molecules, it should be also a powerful tool for biochemical assay, evaluating inhibitory effect of compounds on enzymatic activity. Time-dependent spectral change in real-time monitoring or inhibitor concentration-dependent spectral change after constant-time reaction was processed by factor analysis, by which reaction rate or IC₅₀ value was obtained. Applications to spermidine synthase of Trypanosoma cruzi, which causes Chagas disease, are described

NMR Biochemical Assay for Oxidosqualene Cyclase: Evaluation of Inhibitor Activities on <i>Trypanosoma cruzi</i> and Human Enzymes

Oxidosqualene cyclase (OSC), a membrane-associated protein, is a key enzyme of sterol biosynthesis. Here we report a novel assay for OSC, involving reaction in aqueous solution, NMR quantification in organic solvent, and factor analysis of spectra. We evaluated one known and three novel inhibitors on OSC of <i>Trypanosoma cruzi</i>, a parasite causative of Chagas disease, and compared their effects on human OSC for selectivity. Among them, one novel inhibitor showed a significant parasiticidal activity

NMR Biochemical Assay for Oxidosqualene Cyclase: Evaluation of Inhibitor Activities on <i>Trypanosoma cruzi</i> and Human Enzymes

Oxidosqualene cyclase (OSC), a membrane-associated protein, is a key enzyme of sterol biosynthesis. Here we report a novel assay for OSC, involving reaction in aqueous solution, NMR quantification in organic solvent, and factor analysis of spectra. We evaluated one known and three novel inhibitors on OSC of <i>Trypanosoma cruzi</i>, a parasite causative of Chagas disease, and compared their effects on human OSC for selectivity. Among them, one novel inhibitor showed a significant parasiticidal activity