Project description:The continual spread of novel coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), posing a severe threat to the health worldwide. The main protease (Mpro, alias 3CLpro) of SARS-CoV-2 is a crucial enzyme for the maturation of viral particles and is a very attractive target for designing drugs to treat COVID-19. Here, we propose a multiple conformation-based virtual screening strategy to discover inhibitors that can target SARS-CoV-2 Mpro. Based on this strategy, nine Mpro structures and a protein mimetics library with 8960 commercially available compounds were prepared to carry out ensemble docking for the first time. Five of the nine structures are apo forms presented in different conformations, whereas the other four structures are holo forms complexed with different ligands. The surface plasmon resonance assay revealed that 6 out of 49 compounds had the ability to bind to SARS-CoV-2 Mpro. The fluorescence resonance energy transfer experiment showed that the biochemical half-maximal inhibitory concentration (IC50) values of the six compounds could hamper Mpro activities ranged from 0.69 ± 0.05 to 2.05 ± 0.92 μM. Evaluation of antiviral activity using the cell-based assay indicated that two compounds (Z1244904919 and Z1759961356) could strongly inhibit the cytopathic effect and reduce replication of the living virus in Vero E6 cells with the half-maximal effective concentrations (EC50) of 4.98 ± 1.83 and 8.52 ± 0.92 μM, respectively. The mechanism of the action for the two inhibitors were further elucidated at the molecular level by molecular dynamics simulation and subsequent binding free energy analysis. As a result, the discovered noncovalent reversible inhibitors with novel scaffolds are promising antiviral drug candidates, which may be used to develop the treatment of COVID-19.
Project description:Two years after its emergence, SARS-CoV-2 still represents a serious and global threat to human health. Antiviral drug development usually takes a long time and, to increase the chances of success, chemical variability of hit compounds represents a valuable source for the discovery of new antivirals. In this work, we applied a platform of variably oriented virtual screening campaigns to seek for novel chemical scaffolds for SARS-CoV-2 main protease (Mpro) inhibitors. The study on the resulting 30 best hits led to the identification of a series of structurally unrelated Mpro inhibitors. Some of them exhibited antiviral activity in the low micromolar range against SARS-CoV-2 and other human coronaviruses (HCoVs) in different cell lines. Time-of-addition experiments demonstrated an antiviral effect during the viral replication cycle at a time frame consistent with the inhibition of SARS-CoV-2 Mpro activity. As a proof-of-concept, to validate the pharmaceutical potential of the selected hits against SARS-CoV-2, we rationally optimized one of the hit compounds and obtained two potent SARS-CoV-2 inhibitors with increased activity against Mpro both in vitro and in a cellular context, as well as against SARS-CoV-2 replication in infected cells. This study significantly contributes to the expansion of the chemical variability of SARS-CoV-2 Mpro inhibitors and provides new scaffolds to be exploited for pan-coronavirus antiviral drug development.
Project description:Recent outbreak of COVID-19 pandemic caused by severe acute respiratory syndrome-Coronavirus-2 (SARS-CoV-2) has raised serious global concern for public health. The viral main 3-chymotrypsin-like cysteine protease (Mpro), known to control coronavirus replication and essential for viral life cycle, has been established as an essential drug discovery target for SARS-CoV-2. Herein, we employed computationally screening of Druglib database containing FDA approved drugs against active pocket of SARS-CoV-2 Mpro using MTiopen screen web server, yields a total of 1051 FDA approved drugs with docking energy >-7 kcal/mol. The top 10 screened potential compounds against SARS-CoV-2 Mpro were then studied by re-docking, binding affinity, intermolecular interaction, and complex stability via 100 ns all atoms molecular dynamics (MD) simulation followed by post-simulation analysis, including end point binding free energy, essential dynamics, and residual correlation analysis against native crystal structure ligand N3 inhibitor. Based on comparative molecular simulation and interaction profiling of the screened drugs with SARS-CoV-2 Mpro revealed R428 (-10.5 kcal/mol), Teniposide (-9.8 kcal/mol), VS-5584 (-9.4 kcal/mol), and Setileuton (-8.5 kcal/mol) with stronger stability and affinity than other drugs and N3 inhibitor; and hence, these drugs are advocated for further validation using in vitro enzyme inhibition and in vivo studies against SARS-CoV-2 infection.Communicated by Ramaswamy H. Sarma.
Project description:The COVID-19 pandemic has drastically impacted global economies and public health. Although vaccine development has been successful, it was not sufficient against more infectious mutant strains including the Delta variant indicating a need for alternative treatment strategies such as small molecular compound development. In this work, a series of SARS-CoV-2 main protease (Mpro) inhibitors were designed and tested based on the active compound from high-throughput diverse compound library screens. The most efficacious compound (16b-3) displayed potent SARS-CoV-2 Mpro inhibition with an IC50 value of 116 nM and selectivity against SARS-CoV-2 Mpro when compared to PLpro and RdRp. This new class of compounds could be used as potential leads for further optimization in anti COVID-19 drug discovery.
Project description:Since the outbreak of COVID-19, the pandemic caused by SARS-CoV-2 infection is still spreading at an alarming rate and has caused huge loss of life and economic damage worldwide. Although more than one year has passed, effective treatments for COVID-19 and other pathogenic coronaviruses have not yet been developed. Therefore, the development of SARS-CoV-2 inhibitors is an urgent priority. Given that the Mpro sequences of SARS-CoV-2 and SARS-CoV-1 are 100% identical in the catalytic domain for protein cleavage, the viral main protease (Mpro) is one of the most extensive drug targets in all the drug targets being investigated for SARS-CoV-2. To provide scientific researchers with timely anti-SARS-CoV drug development information for Mpro, we focus on the past and current drug design and development strategies for MPro in this review. We believe that this review will provide meaningful guidance for the design and development of innovative drugs against COVID-19 and other pathogenic coronaviruses in the future.
Project description:The main protease (Mpro) of SARS-CoV-2 is central to viral maturation and is a promising drug target, but little is known about structural aspects of how it binds to its 11 natural cleavage sites. We used biophysical and crystallographic data and an array of biomolecular simulation techniques, including automated docking, molecular dynamics (MD) and interactive MD in virtual reality, QM/MM, and linear-scaling DFT, to investigate the molecular features underlying recognition of the natural Mpro substrates. We extensively analysed the subsite interactions of modelled 11-residue cleavage site peptides, crystallographic ligands, and docked COVID Moonshot-designed covalent inhibitors. Our modelling studies reveal remarkable consistency in the hydrogen bonding patterns of the natural Mpro substrates, particularly on the N-terminal side of the scissile bond. They highlight the critical role of interactions beyond the immediate active site in recognition and catalysis, in particular plasticity at the S2 site. Building on our initial Mpro-substrate models, we used predictive saturation variation scanning (PreSaVS) to design peptides with improved affinity. Non-denaturing mass spectrometry and other biophysical analyses confirm these new and effective 'peptibitors' inhibit Mpro competitively. Our combined results provide new insights and highlight opportunities for the development of Mpro inhibitors as anti-COVID-19 drugs.
Project description:We report a fast-track computationally driven discovery of new SARS-CoV-2 main protease (Mpro) inhibitors whose potency ranges from mM for the initial non-covalent ligands to sub-μM for the final covalent compound (IC50 = 830 ± 50 nM). The project extensively relied on high-resolution all-atom molecular dynamics simulations and absolute binding free energy calculations performed using the polarizable AMOEBA force field. The study is complemented by extensive adaptive sampling simulations that are used to rationalize the different ligand binding poses through the explicit reconstruction of the ligand-protein conformation space. Machine learning predictions are also performed to predict selected compound properties. While simulations extensively use high performance computing to strongly reduce the time-to-solution, they were systematically coupled to nuclear magnetic resonance experiments to drive synthesis and for in vitro characterization of compounds. Such a study highlights the power of in silico strategies that rely on structure-based approaches for drug design and allows the protein conformational multiplicity problem to be addressed. The proposed fluorinated tetrahydroquinolines open routes for further optimization of Mpro inhibitors towards low nM affinities.
Project description:The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has forced the development of direct-acting antiviral drugs due to the coronavirus disease 2019 (COVID-19) pandemic. The main protease of SARS-CoV-2 is a crucial enzyme that breaks down polyproteins synthesized from the viral RNA, making it a validated target for the development of SARS-CoV-2 therapeutics. New chemical phenotypes are frequently discovered in natural goods. In the current study, we used a fluorogenic assay to test a variety of natural products for their ability to inhibit SARS-CoV-2 Mpro. Several compounds were discovered to inhibit Mpro at low micromolar concentrations. It was possible to crystallize robinetin together with SARS-CoV-2 Mpro, and the X-ray structure revealed covalent interaction with the protease's catalytic Cys145 site. Selected potent molecules also exhibited antiviral properties without cytotoxicity. Some of these powerful inhibitors might be utilized as lead compounds for future COVID-19 research.
Project description:The ongoing coronavirus disease 19 caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become fatal for the world with affected population crossing over 25 million in more than 217 countries, consequently declared a global pandemic by the World Health Organization. Unfortunately, neither specific prophylactic or therapeutic drugs nor vaccines are available. To address the unmet medical needs, we explored a strategy identifying new compounds targeting the main protease (Mpro) of SARS-CoV-2. Targeting the SARS-CoV-2 Mpro crystal structure (PDB ID: 6LU7) a combination of in silico screening, molecular docking, and dynamic approaches, a set of 5000 compounds of the ZINC database were screened. As a result, we identified and ranked the top 20 compounds based on the scores of ligand-interaction, their drug-likeness properties, and their predicted antiviral efficacies. The prominent drug-like and potent inhibitory compounds are 2-[2-(2-aminoacetyl) aminoacetyl] amino-3-(4-hydroxyphenyl)-propanamide (ZINC000004762511), 6'-fluoroaristeromycin (ZINC000001483267) and cyclo (L-histidyl-L-histidyl) (ZINC000005116916) scaffolds. Further in vitro and in vivo validations are required to demonstrate anti-SARS-CoV-2 activities.