Pharmacophore modeling, docking and molecular dynamics to identify Leishmania major farnesyl pyrophosphate synthase inhibitors.

Leishmaniasis is caused by protozoa of the genus Leishmania spp. and is considered the second most important protozoa in the world due to the number of cases and mortality. Despite its importance in terms of public health, the treatment of patients is limited and has mostly low levels of efficacy and safety. Farnesyl pyrophosphate synthase (FPPS) acts in the early stages of isoprenoid synthesis, and is important for maintaining the integrity of the lipid bilayer of the parasite that causes the disease. The aim of this work was to identify one potential inhibitor of the FPPS of Leishmania major through virtual screening by pharmacophore modeling and docking. A total of 85,000 compounds from a natural products database (ZINC15) was submitted for virtual hierarchical screening, and the top ranked molecule in both methods was analyzed by intermolecular interaction profile and 20 ns molecular dynamics simulations. These results showed a promising compound from natural products that mimic the major interactions present in the substrate/inhibitor.

Identification of new promising Plasmodium falciparum superoxide dismutase allosteric inhibitors through hierarchical pharmacophore-based virtual screening and molecular dynamics.

Malaria is the world's most widespread protozoan infection, being responsible for more than 445,000 annual deaths. Among the malaria parasites, Plasmodium falciparum is the most prevalent and lethal. In this context, the search for new antimalarial drugs is urgently needed. P. falciparum superoxide dismutase (PfSOD) is an important enzyme involved in the defense mechanism against oxidative stress. The goal of this study was to identify through hierarchical screening on pharmacophore models and molecular dynamics (MD), promising allosteric PfSOD inhibitors that do not show structural requirements for human inhibition. MD simulations of 1000 ps were performed on PfSOD using GROMACS 5.1.2. For this, the AMBER99SB-ILDN force field was adapted to describe the metal-containing system. The simulations indicated stability in the developed system. Therefore, a covariance matrix was generated, in which it was possible to identify residues with correlated and anticorrelated movements with the active site. These results were associated with the results found in the predictor of allosteric sites, AlloSitePro, which affirmed the ability of these residues to delimit an allosteric site. Then, after successive filtering of the Sigma-Aldrich® compounds database for HsSOD1 and PfSOD pharmacophores, 152 compounds were selected, also obeying Lipinski's rule of 5. Further filtering of those compounds based on molecular docking results, toxicity essays, availability, and price filtering led to the selection of a best compound, which was then submitted to MD simulations of 20,000 ps on the allosteric site. The study concludes that the ZINC00626080 compound could be assayed against SODs. Graphical Abstract Plasmodium falciparum superoxide dismutase.

Structure-based drug design studies of UDP-N-acetylglucosamine pyrophosphosrylase, a key enzyme for the control of witches' broom disease.

BACKGROUND: The witches' broom disease is a plague caused by Moniliophthora perniciosa in the Theobroma cacao, which has been reducing the cocoa production since 1989. This issue motivated a genome project that has showing several new molecular targets, which can be developed inhibitors in order to control the plague. Among the molecular targets obtained, the UDP-N-acetylglucosamine pyrophosphorylase (UNAcP) is a key enzyme to construct the fungal cell wall. The inhibition of this enzyme results in the fungal cell death. RESULTS: The results show that the molecular recognition of the enzyme with the substrates occurs mainly by hydrogen bonds between ligands and Arg116, Arg383, Gly381, and Lys408 amino acids; and few hydrophobic interactions with Tyr382 and Lys123 residues. CONCLUSIONS: Among the compounds analyzed, the NAG5 showed the best binding energy (-95.2 kcal/mol). The next steps for the control of witches' broom plague involve the synthesis and biological evaluation of these compounds, which are in progress.