| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1397423 | European Journal of Medicinal Chemistry | 2012 | 7 Pages |
In this study the recombinant enzyme nucleoside hydrolase of Leishmania donovani (rLdNH) was expressed in Escherichia coli in connection with maltose binding protein (MBP). The rLdNH–MBP showed efficient a significant in vitro activity with inosine as substrate. From the coupled reaction with xanthine oxidase (XO) it was possible to determine the kinetic constants of rLdNH–MBP as KM (434 ± 109 μM) and Vmax (0.20 ± 0.02 μM). In addition, two nucleoside analogs (compounds 1 and 2) were tested as prototypes of rLdNH inhibitors. These compounds presented high affinity for the enzyme with Ki values of 1.6 ± 0.2 and 17.0 ± 2.1 μM, respectively, as well as 271 and 26 folds higher than the affinity constant found for inosine. We also determined the type of enzyme inhibition, using double-reciprocal plot for these two compounds and the results confirmed a competitive inhibition. Additional docking studies showed the binding manner of compounds 1 and 2 inside the active site of LdNH revealing the essential residues for an effective inhibition. These results confirm that compounds 1 and 2 are strong rLdNH–MBP inhibitors.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Obtained Leishmania donovani nucleoside hydrolase–maltose binding protein (LdNH–MBP). ► LdNH–MBP was showed to be a soluble, active and stable enzyme tested by NMR. ► Two quinolone nucleoside analogs were tested in vitro as inhibitors of LdNH–MBP. ► Compound 1 showed significant enzymatic activity decrease with Ki 1.6 ± 0.2 μM. ► These nucleosides analogs are new potential drugs for treatment of leishmaniasis.
