Web Services for Molecular Docking Simulations

Applying the bioisosterism strategy to obtain lead compounds against SARS-CoV-2 cysteine proteases: An in-silico approach

SARS-CoV-2 cysteine proteases are essential nonstructural proteins due to their role in the formation of the virus multiple enzyme replication-transcription complex. As a result, those functional proteins are extremely relevant targets in the development of a new drug candidate to fight COVID-19. Based on this fact and guided by the bioisosterism strategy, the present work has selected 126 out of 1050 ligands from DrugBank website. Subsequently, 831 chemical analogs containing bioisosteres, some of which became structurally simplified, were created using the MB-Isoster software, and molecular docking simulations were performed using AutoDock Vina. Finally, a study of physicochemical properties, along with pharmacokinetic profiles, was carried out through SwissADME and ADMETlab 2.0 platforms. The promising results obtained with the molecules encoded as DB00549_BI_005, DB04868_BI_003, DB11984_BI_002, DB12364_BI_006 and DB12805_BI_004 must be confirmed by molecular dynamics studies, followed by in vitro and in vivo empirical tests that ratify the advocated in-silico results.

Evaluation of lipase access tunnels and analysis of substance transport in comparison with experimental data

Lipases (E.C. 3.1.1.3) have buried active sites and used access tunnels in the transport of substrates and products for biotransformation processes. Computational methods are used to predict the trajectory and energy profile of ligands through these tunnels, and they complement the experimental methodologies because they filter data, optimizing laboratory time and experimental costs. Access tunnels of Burkholderia cepacia lipase (BCL), Candida rugosa lipase (CRL), and porcine pancreas lipase (PPL) and the transport of fatty acids, alcohols and esters through the tunnels were evaluated using the online server CaverWeb V1.0, and server calculation results were compared with experimental data (productivity). BCL showed higher productivity with palmitic acid-C16:0 (4029.95 µmol/h mg); CRL obtained productivity for oleic acid-C18:1 (380.80 µmol/h mg), and PPL achieved productivity for lauric acid-C12:0 (71.27 µmol/h mg). The highest probability of transport for BCL is through the tunnels 1 and 2, for CRL through the tunnel 1, and for PPL through the tunnels 1, 2, 3 and 4. Thus, the best in silico result was the transport of the substrates palmitic acid and ethanol and product ethyl palmitate in tunnel 1 of BCL. This result corroborates with the best result for the productivity data (higher productivity for BCL with palmitic acid-4029.95 µmol/h mg). The combination of in silico evaluation and experimental data gave similar results, demonstrating that in silico approaches are a promising alternative for reducing screening tests and minimizing laboratory time in the bio-catalysis area by identifying the lipases with the greatest reaction potential, as in the case of this proposal.

Docking Paradigm in Drug Design

Docking is in demand for the rational computer aided structure based drug design. A review of docking methods and programs is presented. Different types of docking programs are described. They include docking of non-covalent small ligands, protein-protein docking, supercomputer docking, quantum docking, the new generation of docking programs and the application of docking for covalent inhibitors discovery. Taking into account the threat of COVID-19, we present here a short review of docking applications to the discovery of inhibitors of SARS-CoV and SARS-CoV-2 target proteins, including our own result of the search for inhibitors of SARS-CoV-2 main protease using docking and quantum chemical post-processing. The conclusion is made that docking is extremely important in the fight against COVID-19 during the process of development of antivirus drugs having a direct action on SARS-CoV-2 target proteins.

Compuestos Fitoquímicos Dirigidos al Bloqueo de la Polimerasa Viral del SARS-CoV-2 Causante del COVID-19: un Análisis Comparativo de Funciones de Puntuación para Acoplamientos con Interés Biomédico

La pandemia mundial del COVID-19 causada por el SARS-CoV-2 ha hecho necesario buscar alternativas de tratamiento. La OMS ha recomendado el fármaco aprobado por la FDA Remdesivir dirigido a la RNA polimerasa viral. Adicionalmente, se han evaluado computacionalmente compuestos naturales con propiedades antivirales. Sin embargo, estos estudios se centran en el uso de la función de puntuación del algoritmo AutoDock Vina (ADV) para predecir los candidatos. Aquí proponemos evaluar los fitoquímicos Piperina_ID_638024, EPGG_ID_65064, Curcumina_ID_969516, y Capsaicina_ID_1548943 frente a la RNA polimerasa del SARS-CoV-2 (PDB_ID_6NUR), usando Remdesivir_ID_121304016 como control, mediante análisis computacional, comparativo y multivariado de las funciones de puntuación ADV, PLANTS, MolDock, Rerank y DockT considerando la solubilidad de ligandos e hidrofobicidad de las cavidades implicadas en las interacciones, para aumentar la precisión en la predicción de los mejores acoplamientos de los compuestos naturales frente al COVID-19. Encontramos que 4/5 de las funciones de puntuación exceptuando ADV predijeron el acoplamiento termodinámicamente más favorable con Piperina, superando a Remdesivir. También observamos que las calificaciones de PLANTS, ADV y DockT se afectan por la solubilidad del ligando e hidrofobicidad de cavidades. Bajo las condiciones de este estudio concluimos que los algoritmos MolDock y Rerank son más adecuados para el cribado rápido y la reorganización de acoplamientos, cuando se trabaje con ligandos solubles (Rp = 0.70 para ambos), indistintamente de su polaridad, y dirigidos a cavidades hidrofóbicas de la RNA polimerasa del SARS-CoV-2 (Rp = 0.95 y Rp = 0.90, respectivamente), especialmente para los enfoques computacionales en el contexto de la investigación de fármacos frente al COVID-19.

Virtual screening web servers: designing chemical probes and drug candidates in the cyberspace

The interplay between life sciences and advancing technology drives a continuous cycle of chemical data growth; these data are most often stored in open or partially open databases. In parallel, many different types of algorithms are being developed to manipulate these chemical objects and associated bioactivity data. Virtual screening methods are among the most popular computational approaches in pharmaceutical research. Today, user-friendly web-based tools are available to help scientists perform virtual screening experiments. This article provides an overview of internet resources enabling and supporting chemical biology and early drug discovery with a main emphasis on web servers dedicated to virtual ligand screening and small-molecule docking. This survey first introduces some key concepts and then presents recent and easily accessible virtual screening and related target-fishing tools as well as briefly discusses case studies enabled by some of these web services. Notwithstanding further improvements, already available web-based tools not only contribute to the design of bioactive molecules and assist drug repositioning but also help to generate new ideas and explore different hypotheses in a timely fashion while contributing to teaching in the field of drug development.