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1.
PLoS One ; 15(7): e0235030, 2020.
Article in English | MEDLINE | ID: covidwho-689509

ABSTRACT

The incidence of 2019 novel corona virus (SARS-CoV-2) has created a medical emergency throughout the world. Various efforts have been made to develop the vaccine or effective treatments against the disease. The discovery of crystal structure of SARS-CoV-2 main protease has made the in silico identification of its inhibitors possible. Based on its critical role in viral replication, the viral protease can prove to be a promising "target" for antiviral drug therapy. We have systematically screened an in-house library of 15,754 natural and synthetic compounds, established at International Center for Chemical and Biological Sciences, University of Karachi. The in silico search for potential viral protease inhibitors resulted in nine top ranked ligands (compounds 1-9) against SARS-CoV-2 main protease (PDB ID: 6LU7) based on docking scores, and predictive binding energies. The in silico studies were updated via carrying out the docking, and predictive binding energy estimation, with a recently reported crystal structure of main protease (PDB ID: 6Y2F) at a better resolution i.e., 1.95 Å. Compound 2 (molecular bank code AAA396) was found to have highest negative binding energy of -71.63 kcal/mol for 6LU7. While compound 3 (molecular bank code AAD146) exhibited highest negative binding energy of -81.92 kcal/mol for 6Y2F. The stability of the compounds- in complex with viral protease was analyzed by Molecular Dynamics simulation studies, and was found to be stable over the course of 20 ns simulation time. Compound 2, and 3 were predicted to be the significant inhibitors of SARS-CoV-2 3CL hydrolase (Mpro) among the nine short listed compounds.


Subject(s)
Molecular Docking Simulation , Molecular Dynamics Simulation , Protease Inhibitors/chemistry , Viral Nonstructural Proteins/antagonists & inhibitors , Betacoronavirus/drug effects , Coronavirus Infections , Cysteine Endopeptidases , Drug Discovery , Humans , Ligands , Pandemics , Pneumonia, Viral , Protease Inhibitors/pharmacology , Protein Structure, Tertiary
2.
J Proteome Res ; 19(4): 1351-1360, 2020 04 03.
Article in English | MEDLINE | ID: covidwho-688546

ABSTRACT

As the infection of 2019-nCoV coronavirus is quickly developing into a global pneumonia epidemic, the careful analysis of its transmission and cellular mechanisms is sorely needed. In this Communication, we first analyzed two recent studies that concluded that snakes are the intermediate hosts of 2019-nCoV and that the 2019-nCoV spike protein insertions share a unique similarity to HIV-1. However, the reimplementation of the analyses, built on larger scale data sets using state-of-the-art bioinformatics methods and databases, presents clear evidence that rebuts these conclusions. Next, using metagenomic samples from Manis javanica, we assembled a draft genome of the 2019-nCoV-like coronavirus, which shows 73% coverage and 91% sequence identity to the 2019-nCoV genome. In particular, the alignments of the spike surface glycoprotein receptor binding domain revealed four times more variations in the bat coronavirus RaTG13 than in the Manis coronavirus compared with 2019-nCoV, suggesting the pangolin as a missing link in the transmission of 2019-nCoV from bats to human.


Subject(s)
Betacoronavirus/genetics , Coronavirus Infections/virology , Genome, Viral/genetics , Host-Pathogen Interactions , Models, Molecular , Pneumonia, Viral/virology , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Amino Acid Sequence , Animals , Betacoronavirus/classification , Eutheria/virology , HIV-1/genetics , Humans , Metagenome , Pandemics , Protein Structure, Tertiary , Sequence Alignment , Sequence Analysis, Protein , Snakes/virology
3.
Sci Rep ; 10(1): 10895, 2020 07 02.
Article in English | MEDLINE | ID: covidwho-629396

ABSTRACT

In the past two decades, 7 coronaviruses have infected the human population, with two major outbreaks caused by SARS-CoV and MERS-CoV in the year 2002 and 2012, respectively. Currently, the entire world is facing a pandemic of another coronavirus, SARS-CoV-2, with a high fatality rate. The spike glycoprotein of SARS-CoV-2 mediates entry of virus into the host cell and is one of the most important antigenic determinants, making it a potential candidate for a vaccine. In this study, we have computationally designed a multi-epitope vaccine using spike glycoprotein of SARS-CoV-2. The overall quality of the candidate vaccine was validated in silico and Molecular Dynamics Simulation confirmed the stability of the designed vaccine. Docking studies revealed stable interactions of the vaccine with Toll-Like Receptors and MHC Receptors. The in silico cloning and codon optimization supported the proficient expression of the designed vaccine in E. coli expression system. The efficiency of the candidate vaccine to trigger an effective immune response was assessed by an in silico immune simulation. The computational analyses suggest that the designed multi-epitope vaccine is structurally stable which can induce specific immune responses and thus, can be a potential vaccine candidate against SARS-CoV-2.


Subject(s)
Betacoronavirus/immunology , Coronavirus Infections/prevention & control , Epitopes, B-Lymphocyte/immunology , Epitopes, T-Lymphocyte/immunology , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , Spike Glycoprotein, Coronavirus/immunology , Viral Vaccines/immunology , Antibody Affinity/immunology , Betacoronavirus/chemistry , Betacoronavirus/genetics , Coronavirus Infections/virology , Histocompatibility Antigens/immunology , Humans , Molecular Docking Simulation , Molecular Dynamics Simulation , Peptidyl-Dipeptidase A/metabolism , Phylogeny , Pneumonia, Viral/virology , Protein Structure, Tertiary , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/metabolism , Toll-Like Receptor 2/immunology , Toll-Like Receptor 2/metabolism , Toll-Like Receptor 4/immunology , Toll-Like Receptor 4/metabolism , Viral Vaccines/metabolism
4.
Nature ; 582(7811): 289-293, 2020 06.
Article in English | MEDLINE | ID: covidwho-608904

ABSTRACT

A new coronavirus, known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is the aetiological agent responsible for the 2019-2020 viral pneumonia outbreak of coronavirus disease 2019 (COVID-19)1-4. Currently, there are no targeted therapeutic agents for the treatment of this disease, and effective treatment options remain very limited. Here we describe the results of a programme that aimed to rapidly discover lead compounds for clinical use, by combining structure-assisted drug design, virtual drug screening and high-throughput screening. This programme focused on identifying drug leads that target main protease (Mpro) of SARS-CoV-2: Mpro is a key enzyme of coronaviruses and has a pivotal role in mediating viral replication and transcription, making it an attractive drug target for SARS-CoV-25,6. We identified a mechanism-based inhibitor (N3) by computer-aided drug design, and then determined the crystal structure of Mpro of SARS-CoV-2 in complex with this compound. Through a combination of structure-based virtual and high-throughput screening, we assayed more than 10,000 compounds-including approved drugs, drug candidates in clinical trials and other pharmacologically active compounds-as inhibitors of Mpro. Six of these compounds inhibited Mpro, showing half-maximal inhibitory concentration values that ranged from 0.67 to 21.4 µM. One of these compounds (ebselen) also exhibited promising antiviral activity in cell-based assays. Our results demonstrate the efficacy of our screening strategy, which can lead to the rapid discovery of drug leads with clinical potential in response to new infectious diseases for which no specific drugs or vaccines are available.


Subject(s)
Betacoronavirus/chemistry , Cysteine Endopeptidases/chemistry , Drug Discovery/methods , Models, Molecular , Protease Inhibitors/chemistry , Viral Nonstructural Proteins/antagonists & inhibitors , Viral Nonstructural Proteins/chemistry , Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Betacoronavirus/drug effects , Cells, Cultured/virology , Coronavirus Infections/enzymology , Coronavirus Infections/virology , Drug Design , Drug Evaluation, Preclinical , Humans , Pandemics , Pneumonia, Viral/enzymology , Pneumonia, Viral/virology , Protease Inhibitors/pharmacology , Protein Structure, Tertiary
5.
Sci Rep ; 10(1): 9294, 2020 06 09.
Article in English | MEDLINE | ID: covidwho-592060

ABSTRACT

As of today, there is no antiviral for the treatment of the SARS-CoV-2 infection, and the development of a vaccine might take several months or even years. The structural superposition of the hepatitis C virus polymerase bound to sofosbuvir, a nucleoside analog antiviral approved for hepatitis C virus infections, with the SARS-CoV polymerase shows that the residues that bind to the drug are present in the latter. Moreover, a multiple alignment of several SARS-CoV-2, SARS and MERS-related coronaviruses polymerases shows that these residues are conserved in all these viruses, opening the possibility to use sofosbuvir against these highly infectious pathogens.


Subject(s)
Antiviral Agents/chemistry , Betacoronavirus/enzymology , Coronavirus Infections/virology , Pandemics/prevention & control , Pneumonia, Viral/virology , RNA Replicase/chemistry , Sofosbuvir/chemistry , Viral Nonstructural Proteins/chemistry , Antiviral Agents/therapeutic use , Base Sequence , Catalytic Domain , Computer Simulation , Coronavirus Infections/drug therapy , Humans , Middle East Respiratory Syndrome Coronavirus/enzymology , Pneumonia, Viral/drug therapy , Protein Binding , Protein Structure, Tertiary , RNA Replicase/genetics , SARS Virus/enzymology , Severe Acute Respiratory Syndrome/drug therapy , Severe Acute Respiratory Syndrome/virology , Sofosbuvir/therapeutic use , Viral Nonstructural Proteins/genetics
6.
J Phys Chem Lett ; 11(12): 4785-4790, 2020 Jun 18.
Article in English | MEDLINE | ID: covidwho-548363

ABSTRACT

The severe acute respiratory syndrome coronavirus (SARS-CoV-2) pandemic is setting the global health crisis of our time, causing a devastating societal and economic burden. An idiosyncratic trait of coronaviruses is the presence of spike glycoproteins on the viral envelope, which mediate the virus binding to specific host receptor, enabling its entry into the human cells. In spite of the high sequence identity of SARS-CoV-2 with its closely related SARS-CoV emerged in 2002, the atomic-level determinants underlining the molecular recognition of SARS-CoV-2 to the angiotensin-converting enzyme 2 (ACE2) receptor and, thus, the rapid virus spread into human body, remain unresolved. Here, multi-microsecond-long molecular dynamics simulations enabled us to unprecedentedly dissect the key molecular traits liable of the higher affinity/specificity of SARS-CoV-2 toward ACE2 as compared to SARS-CoV. This supplies a minute per-residue contact map underlining its stunningly high infectivity. Harnessing this knowledge is pivotal for urgently developing effective medical countermeasures to face the ongoing global health crisis.


Subject(s)
Betacoronavirus/metabolism , Glycoproteins/metabolism , Molecular Dynamics Simulation , Viral Proteins/metabolism , Amino Acid Motifs , Coronavirus Infections/pathology , Coronavirus Infections/virology , Glycoproteins/chemistry , Humans , Hydrogen Bonding , Pandemics , Peptidyl-Dipeptidase A/chemistry , Peptidyl-Dipeptidase A/metabolism , Pneumonia, Viral/pathology , Pneumonia, Viral/virology , Protein Binding , Protein Structure, Quaternary , Protein Structure, Tertiary , Quantum Theory , SARS Virus/metabolism , Viral Proteins/chemistry , Virus Attachment
7.
Int J Mol Sci ; 21(11)2020 May 27.
Article in English | MEDLINE | ID: covidwho-382045

ABSTRACT

Since the outbreak of the COVID-19 pandemic in December 2019 and its rapid spread worldwide, the scientific community has been under pressure to react and make progress in the development of an effective treatment against the virus responsible for the disease. Here, we implement an original virtual screening (VS) protocol for repositioning approved drugs in order to predict which of them could inhibit the main protease of the virus (M-pro), a key target for antiviral drugs given its essential role in the virus' replication. Two different libraries of approved drugs were docked against the structure of M-pro using Glide, FRED and AutoDock Vina, and only the equivalent high affinity binding modes predicted simultaneously by the three docking programs were considered to correspond to bioactive poses. In this way, we took advantage of the three sampling algorithms to generate hypothetic binding modes without relying on a single scoring function to rank the results. Seven possible SARS-CoV-2 M-pro inhibitors were predicted using this approach: Perampanel, Carprofen, Celecoxib, Alprazolam, Trovafloxacin, Sarafloxacin and ethyl biscoumacetate. Carprofen and Celecoxib have been selected by the COVID Moonshot initiative for in vitro testing; they show 3.97 and 11.90% M-pro inhibition at 50 µM, respectively.


Subject(s)
Betacoronavirus/enzymology , Protease Inhibitors/chemistry , Subtilisins/antagonists & inhibitors , Viral Proteins/antagonists & inhibitors , Antiviral Agents/chemistry , Antiviral Agents/metabolism , Binding Sites , Carbazoles/chemistry , Carbazoles/metabolism , Celecoxib/chemistry , Celecoxib/metabolism , Coronavirus Infections/pathology , Coronavirus Infections/virology , Drug Repositioning , Humans , Molecular Docking Simulation , Mutation, Missense , Pandemics , Pneumonia, Viral/pathology , Pneumonia, Viral/virology , Protease Inhibitors/metabolism , Protein Structure, Tertiary , Subtilisins/genetics , Subtilisins/metabolism , Viral Proteins/genetics , Viral Proteins/metabolism
8.
Int J Infect Dis ; 96: 459-460, 2020 Jul.
Article in English | MEDLINE | ID: covidwho-361379

ABSTRACT

The increasing number of deaths due to the COVID-19 pandemic has raised serious global concerns. Increased testing capacity and ample intensive care availability could explain lower mortality in some countries compared to others. Nevertheless, it is also plausible that the SARS-CoV-2 mutations giving rise to different phylogenetic clades are responsible for the apparent death rate disparities around the world. Current research literature linking the genetic make-up of SARS-CoV-2 with fatalities is lacking. Here, we suggest that this disparity in fatality rates may be attributed to SARS-CoV-2 evolving mutations and urge the international community to begin addressing the phylogenetic clade classification of SARS-CoV-2 in relation to clinical outcomes.


Subject(s)
Betacoronavirus/genetics , Coronavirus Infections/genetics , Coronavirus Infections/mortality , Pneumonia, Viral/genetics , Pneumonia, Viral/mortality , Spike Glycoprotein, Coronavirus/genetics , Betacoronavirus/chemistry , Humans , Models, Molecular , Mutation , Pandemics , Phylogeny , Protein Structure, Tertiary , Spike Glycoprotein, Coronavirus/chemistry
9.
Virus Res ; 285: 198022, 2020 08.
Article in English | MEDLINE | ID: covidwho-276868

ABSTRACT

The recent outbreak of the deadly COVID-19 disease, being caused by the novel coronavirus (SARS-CoV-2), has put the world on red alert as it keeps spreading and recording more fatalities. Research efforts are being carried out to curtail the disease from spreading as it has been declared as of global health emergency. Hence, there is an exigent need to identify and design drugs that are capable of curing the infection and hinder its continual spread across the globe. Herein, a computer-aided drug design tool known as the virtual screening method was used to screen a database of 44 million compounds to find compounds that have the potential to inhibit the surface glycoprotein responsible for virus entry and binding. The consensus scoring approach selected three compounds with promising physicochemical properties and favorable molecular interactions with the target protein. These selected compounds can undergo lead optimization to be further developed as drugs that can be used in treating the COVID-19 disease.


Subject(s)
Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Betacoronavirus/drug effects , Coronavirus Infections/drug therapy , Drug Design , Pneumonia, Viral/drug therapy , Spike Glycoprotein, Coronavirus/antagonists & inhibitors , Antiviral Agents/metabolism , Antiviral Agents/toxicity , Betacoronavirus/physiology , Drug Evaluation, Preclinical/methods , Humans , Ligands , Machine Learning , Models, Molecular , Molecular Docking Simulation , Pandemics , Protein Binding , Protein Structure, Tertiary , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/metabolism , Virus Internalization/drug effects
10.
Biochem Biophys Res Commun ; 527(3): 702-708, 2020 06 30.
Article in English | MEDLINE | ID: covidwho-260248

ABSTRACT

The spread of COVID-19 caused by the SARS-CoV-2 outbreak has been growing since its first identification in December 2019. The publishing of the first SARS-CoV-2 genome made a valuable source of data to study the details about its phylogeny, evolution, and interaction with the host. Protein-protein binding assays have confirmed that Angiotensin-converting enzyme 2 (ACE2) is more likely to be the cell receptor through which the virus invades the host cell. In the present work, we provide an insight into the interaction of the viral spike Receptor Binding Domain (RBD) from different coronavirus isolates with host ACE2 protein. By calculating the binding energy score between RBD and ACE2, we highlighted the putative jump in the affinity from a progenitor form of SARS-CoV-2 to the current virus responsible for COVID-19 outbreak. Our result was consistent with previously reported phylogenetic analysis and corroborates the opinion that the interface segment of the spike protein RBD might be acquired by SARS-CoV-2 via a complex evolutionary process rather than a progressive accumulation of mutations. We also highlighted the relevance of Q493 and P499 amino acid residues of SARS-CoV-2 RBD for binding to human ACE2 and maintaining the stability of the interface. Moreover, we show from the structural analysis that it is unlikely for the interface residues to be the result of genetic engineering. Finally, we studied the impact of eight different variants located at the interaction surface of ACE2, on the complex formation with SARS-CoV-2 RBD. We found that none of them is likely to disrupt the interaction with the viral RBD of SARS-CoV-2.


Subject(s)
Betacoronavirus/chemistry , Peptidyl-Dipeptidase A/chemistry , Spike Glycoprotein, Coronavirus/chemistry , Amino Acid Sequence , Binding Sites , Coronavirus Infections , Humans , Molecular Docking Simulation , Pandemics , Phylogeny , Pneumonia, Viral , Protein Domains , Protein Structure, Tertiary
11.
J Phys Chem Lett ; 11(11): 4413-4420, 2020 Jun 04.
Article in English | MEDLINE | ID: covidwho-258961

ABSTRACT

Currently, the new coronavirus disease 2019 (COVID-19) is a global pandemic without any well-calibrated treatment. To inactivate the SARS-CoV-2 virus that causes COVID-19, the main protease (Mpro) that performs key biological functions in the virus has been the focus of extensive studies. With the fast-response experimental efforts, the crystal structures of Mpro of the SARS-CoV-2 virus have just become available recently. Herein, we theoretically investigated the mechanism of binding between the Mpro's pocket and various marketed drug molecules being tested in clinics to fight COVID-19 that show promising outcomes. By combining the existing experimental results with our computational ones, we revealed an important ligand binding mechanism of the Mpro, demonstrating that the binding stability of a ligand inside the Mpro pocket can be significantly improved if part of the ligand occupies its so-called "anchor" site. Along with the highly potent drugs and/or molecules (such as nelfinavir) revealed in this study, the newly discovered binding mechanism paves the way for further optimizations and designs of Mpro's inhibitors with a high binding affinity.


Subject(s)
Coronavirus Infections/drug therapy , Cysteine Endopeptidases/chemistry , Pneumonia, Viral/drug therapy , Protease Inhibitors/chemistry , Viral Nonstructural Proteins/chemistry , Betacoronavirus/isolation & purification , Binding Sites , Coronavirus Infections/pathology , Coronavirus Infections/virology , Cysteine Endopeptidases/metabolism , Drug Design , Humans , Ligands , Molecular Dynamics Simulation , Pandemics , Pneumonia, Viral/pathology , Pneumonia, Viral/virology , Protease Inhibitors/metabolism , Protein Structure, Tertiary , Viral Nonstructural Proteins/metabolism
12.
J Phys Chem Lett ; 11(11): 4430-4435, 2020 Jun 04.
Article in English | MEDLINE | ID: covidwho-233085

ABSTRACT

The pandemic outbreak of a new coronavirus (CoV), SARS-CoV-2, has captured the world's attention, demonstrating that CoVs represent a continuous global threat. As this is a highly contagious virus, it is imperative to understand RNA-dependent-RNA-polymerase (RdRp), the key component in virus replication. Although the SARS-CoV-2 genome shares 80% sequence identity with severe acute respiratory syndrome SARS-CoV, their RdRps and nucleotidyl-transferases (NiRAN) share 98.1% and 93.2% identity, respectively. Sequence alignment of six coronaviruses demonstrated higher identity among their RdRps (60.9%-98.1%) and lower identity among their Spike proteins (27%-77%). Thus, a 3D structural model of RdRp, NiRAN, non-structural protein 7 (nsp7), and nsp8 of SARS-CoV-2 was generated by modeling starting from the SARS counterpart structures. Furthermore, we demonstrate the binding poses of three viral RdRp inhibitors (Galidesivir, Favipiravir, and Penciclovir), which were recently reported to have clinical significance for SARS-CoV-2. The network of interactions established by these drug molecules affirms their efficacy to inhibit viral RNA replication and provides an insight into their structure-based rational optimization for SARS-CoV-2 inhibition.


Subject(s)
Betacoronavirus/enzymology , Nucleotidyltransferases/chemistry , RNA Replicase/chemistry , Adenine/analogs & derivatives , Adenine/chemistry , Adenine/metabolism , Amides/chemistry , Amides/metabolism , Antiviral Agents/chemistry , Antiviral Agents/metabolism , Betacoronavirus/isolation & purification , Binding Sites , Coronavirus Infections/epidemiology , Coronavirus Infections/pathology , Coronavirus Infections/virology , Humans , Molecular Docking Simulation , Nucleotidyltransferases/metabolism , Pandemics , Pneumonia, Viral/epidemiology , Pneumonia, Viral/pathology , Pneumonia, Viral/virology , Protein Structure, Tertiary , Pyrazines/chemistry , Pyrazines/metabolism , Pyrrolidines/chemistry , Pyrrolidines/metabolism , RNA Replicase/metabolism
13.
Science ; 369(6501): 330-333, 2020 07 17.
Article in English | MEDLINE | ID: covidwho-187772

ABSTRACT

The emergence of the betacoronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), represents a considerable threat to global human health. Vaccine development is focused on the principal target of the humoral immune response, the spike (S) glycoprotein, which mediates cell entry and membrane fusion. The SARS-CoV-2 S gene encodes 22 N-linked glycan sequons per protomer, which likely play a role in protein folding and immune evasion. Here, using a site-specific mass spectrometric approach, we reveal the glycan structures on a recombinant SARS-CoV-2 S immunogen. This analysis enables mapping of the glycan-processing states across the trimeric viral spike. We show how SARS-CoV-2 S glycans differ from typical host glycan processing, which may have implications in viral pathobiology and vaccine design.


Subject(s)
Betacoronavirus/chemistry , Polysaccharides/chemistry , Spike Glycoprotein, Coronavirus/chemistry , Binding Sites , Coronavirus Infections , Glycopeptides/chemistry , Glycopeptides/immunology , Glycosylation , Humans , Mass Spectrometry , Models, Molecular , Oligosaccharides/chemistry , Pandemics , Pneumonia, Viral , Protein Structure, Tertiary , Recombinant Proteins/chemistry , Recombinant Proteins/immunology , Spike Glycoprotein, Coronavirus/immunology
14.
Biochem Biophys Res Commun ; 527(3): 618-623, 2020 06 30.
Article in English | MEDLINE | ID: covidwho-155056

ABSTRACT

The nucleocapsid (N) protein is an important antigen for coronavirus, which participate in RNA package and virus particle release. In this study, we expressed the N protein of SARS-CoV-2 and characterized its biochemical properties. Static light scattering, size exclusive chromatography, and small-angle X-ray scattering (SAXS) showed that the purified N protein is largely a dimer in solution. CD spectra showed that it has a high percentage of disordered region at room temperature while it was best structured at 55 °C, suggesting its structural dynamics. Fluorescence polarization assay showed it has non-specific nucleic acid binding capability, which raised a concern in using it as a diagnostic marker. Immunoblot assays confirmed the presence of IgA, IgM and IgG antibodies against N antigen in COVID-19 infection patients' sera, proving the importance of this antigen in host immunity and diagnostics.


Subject(s)
Betacoronavirus/chemistry , Nucleocapsid Proteins/chemistry , Antibodies, Viral/blood , Coronavirus Infections , Humans , Nucleic Acids , Pandemics , Pneumonia, Viral , Protein Binding , Protein Multimerization , Protein Structure, Tertiary , Scattering, Small Angle , X-Ray Diffraction
15.
J Med Virol ; 92(6): 618-631, 2020 06.
Article in English | MEDLINE | ID: covidwho-141989

ABSTRACT

Recently, a novel coronavirus (SARS-COV-2) emerged which is responsible for the recent outbreak in Wuhan, China. Genetically, it is closely related to SARS-CoV and MERS-CoV. The situation is getting worse and worse, therefore, there is an urgent need for designing a suitable peptide vaccine component against the SARS-COV-2. Here, we characterized spike glycoprotein to obtain immunogenic epitopes. Next, we chose 13 Major Histocompatibility Complex-(MHC) I and 3 MHC-II epitopes, having antigenic properties. These epitopes are usually linked to specific linkers to build vaccine components and molecularly dock on toll-like receptor-5 to get binding affinity. Therefore, to provide a fast immunogenic profile of these epitopes, we performed immunoinformatics analysis so that the rapid development of the vaccine might bring this disastrous situation to the end earlier.


Subject(s)
Betacoronavirus/immunology , Coronavirus Infections/prevention & control , Epitopes, B-Lymphocyte/chemistry , Epitopes, T-Lymphocyte/chemistry , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , Spike Glycoprotein, Coronavirus/chemistry , Toll-Like Receptor 5/chemistry , Viral Vaccines/chemistry , Amino Acid Sequence , Betacoronavirus/genetics , Betacoronavirus/pathogenicity , Binding Sites , Computational Biology/methods , Coronavirus Infections/immunology , Coronavirus Infections/virology , Epitopes/chemistry , Epitopes/genetics , Epitopes/immunology , Epitopes, B-Lymphocyte/genetics , Epitopes, B-Lymphocyte/immunology , Epitopes, T-Lymphocyte/genetics , Epitopes, T-Lymphocyte/immunology , Histocompatibility Antigens Class I/chemistry , Histocompatibility Antigens Class I/genetics , Histocompatibility Antigens Class I/immunology , Histocompatibility Antigens Class II/chemistry , Histocompatibility Antigens Class II/genetics , Histocompatibility Antigens Class II/immunology , Humans , Middle East Respiratory Syndrome Coronavirus/genetics , Middle East Respiratory Syndrome Coronavirus/immunology , Middle East Respiratory Syndrome Coronavirus/pathogenicity , Molecular Docking Simulation , Pneumonia, Viral/immunology , Pneumonia, Viral/virology , Protein Binding , Protein Interaction Domains and Motifs , Protein Structure, Tertiary , SARS Virus/genetics , SARS Virus/immunology , SARS Virus/pathogenicity , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Toll-Like Receptor 5/genetics , Toll-Like Receptor 5/immunology , Vaccines, Subunit , Viral Vaccines/immunology
16.
Science ; 368(6497): 1331-1335, 2020 06 19.
Article in English | MEDLINE | ID: covidwho-108792

ABSTRACT

SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) is the etiological agent responsible for the global COVID-19 (coronavirus disease 2019) outbreak. The main protease of SARS-CoV-2, Mpro, is a key enzyme that plays a pivotal role in mediating viral replication and transcription. We designed and synthesized two lead compounds (11a and 11b) targeting Mpro Both exhibited excellent inhibitory activity and potent anti-SARS-CoV-2 infection activity. The x-ray crystal structures of SARS-CoV-2 Mpro in complex with 11a or 11b, both determined at a resolution of 1.5 angstroms, showed that the aldehyde groups of 11a and 11b are covalently bound to cysteine 145 of Mpro Both compounds showed good pharmacokinetic properties in vivo, and 11a also exhibited low toxicity, which suggests that these compounds are promising drug candidates.


Subject(s)
Antiviral Agents/chemistry , Betacoronavirus/enzymology , Drug Design , Viral Nonstructural Proteins/antagonists & inhibitors , Animals , Antiviral Agents/pharmacology , Betacoronavirus/drug effects , Catalytic Domain , Chlorocebus aethiops , Coronavirus Infections/drug therapy , Cysteine Endopeptidases , Dogs , Drug Evaluation, Preclinical , Female , Humans , Male , Mice , Molecular Structure , Pandemics , Pneumonia, Viral/drug therapy , Protein Structure, Tertiary , Rats, Sprague-Dawley , Toxicity Tests , Vero Cells
17.
Int J Antimicrob Agents ; 55(5): 105960, 2020 May.
Article in English | MEDLINE | ID: covidwho-65372

ABSTRACT

The recent emergence of the novel pathogenic SARS-coronavirus 2 (SARS-CoV-2) is responsible for a worldwide pandemic. Given the global health emergency, drug repositioning is the most reliable option to design an efficient therapy for infected patients without delay. The first step of the viral replication cycle [i.e. attachment to the surface of respiratory cells, mediated by the spike (S) viral protein] offers several potential therapeutic targets. The S protein uses the angiotension-converting enzyme-2 (ACE-2) receptor for entry, but also sialic acids linked to host cell surface gangliosides. Using a combination of structural and molecular modelling approaches, this study showed that chloroquine (CLQ), one of the drugs currently under investigation for SARS-CoV-2 treatment, binds sialic acids and gangliosides with high affinity. A new type of ganglioside-binding domain at the tip of the N-terminal domain of the SARS-CoV-2 S protein was identified. This domain (111-158), which is fully conserved among clinical isolates worldwide, may improve attachment of the virus to lipid rafts and facilitate contact with the ACE-2 receptor. This study showed that, in the presence of CLQ [or its more active derivative, hydroxychloroquine (CLQ-OH)], the viral S protein is no longer able to bind gangliosides. The identification of this new mechanism of action of CLQ and CLQ-OH supports the use of these repositioned drugs to cure patients infected with SARS-CoV-2. The in-silico approaches used in this study might also be used to assess the efficiency of a broad range of repositioned and/or innovative drug candidates before clinical evaluation.


Subject(s)
Betacoronavirus/drug effects , Chloroquine/pharmacology , Coronavirus Infections/drug therapy , Hydroxychloroquine/pharmacology , Pneumonia, Viral/drug therapy , Amino Acid Sequence , Betacoronavirus/chemistry , Chloroquine/chemistry , Chloroquine/therapeutic use , Humans , Hydroxychloroquine/chemistry , Hydroxychloroquine/therapeutic use , Models, Molecular , Molecular Targeted Therapy , Pandemics , Protein Structure, Quaternary , Protein Structure, Tertiary , Sequence Analysis, Protein , Spike Glycoprotein, Coronavirus/chemistry
18.
Biochemistry ; 59(18): 1769-1779, 2020 05 12.
Article in English | MEDLINE | ID: covidwho-59683

ABSTRACT

Since the emergence of a novel coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first reported from Wuhan, China, neither a specific vaccine nor an antiviral drug against SARS-CoV-2 has become available. However, a combination of two HIV-1 protease inhibitors, lopinavir and ritonavir, has been found to be effective against SARS-CoV, and both drugs could bind well to the SARS-CoV 3C-like protease (SARS-CoV 3CLpro). In this work, molecular complexation between each inhibitor and SARS-CoV-2 3CLpro was studied using all-atom molecular dynamics simulations, free energy calculations, and pair interaction energy analyses based on MM/PB(GB)SA and FMO-MP2/PCM/6-31G* methods. Both anti-HIV drugs interacted well with the residues at the active site of SARS-CoV-2 3CLpro. Ritonavir showed a somewhat higher number atomic contacts, a somewhat higher binding efficiency, and a somewhat higher number of key binding residues compared to lopinavir, which correspond with the slightly lower water accessibility at the 3CLpro active site. In addition, only ritonavir could interact with the oxyanion hole residues N142 and G143 via the formation of two hydrogen bonds. The interactions in terms of electrostatics, dispersion, and charge transfer played an important role in the drug binding. The obtained results demonstrated how repurposed anti-HIV drugs could be used to combat COVID-19.


Subject(s)
Antiviral Agents/pharmacology , Coronavirus Infections/drug therapy , Enzyme Inhibitors/pharmacology , Lopinavir/chemistry , Lopinavir/pharmacology , Pneumonia, Viral/drug therapy , Ritonavir/chemistry , Ritonavir/pharmacology , Antiviral Agents/therapeutic use , Betacoronavirus/drug effects , Betacoronavirus/enzymology , Catalytic Domain , Coronavirus Infections/enzymology , Coronavirus Infections/virology , Cysteine Endopeptidases/chemistry , Cysteine Endopeptidases/metabolism , Drug Repositioning , Enzyme Inhibitors/therapeutic use , Humans , Lopinavir/therapeutic use , Molecular Dynamics Simulation , Pandemics , Pneumonia, Viral/enzymology , Pneumonia, Viral/virology , Protein Binding , Protein Structure, Tertiary , Ritonavir/therapeutic use , Viral Nonstructural Proteins/chemistry , Viral Nonstructural Proteins/metabolism
19.
Nature ; 582(7811): 289-293, 2020 06.
Article in English | MEDLINE | ID: covidwho-47105

ABSTRACT

A new coronavirus, known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is the aetiological agent responsible for the 2019-2020 viral pneumonia outbreak of coronavirus disease 2019 (COVID-19)1-4. Currently, there are no targeted therapeutic agents for the treatment of this disease, and effective treatment options remain very limited. Here we describe the results of a programme that aimed to rapidly discover lead compounds for clinical use, by combining structure-assisted drug design, virtual drug screening and high-throughput screening. This programme focused on identifying drug leads that target main protease (Mpro) of SARS-CoV-2: Mpro is a key enzyme of coronaviruses and has a pivotal role in mediating viral replication and transcription, making it an attractive drug target for SARS-CoV-25,6. We identified a mechanism-based inhibitor (N3) by computer-aided drug design, and then determined the crystal structure of Mpro of SARS-CoV-2 in complex with this compound. Through a combination of structure-based virtual and high-throughput screening, we assayed more than 10,000 compounds-including approved drugs, drug candidates in clinical trials and other pharmacologically active compounds-as inhibitors of Mpro. Six of these compounds inhibited Mpro, showing half-maximal inhibitory concentration values that ranged from 0.67 to 21.4 µM. One of these compounds (ebselen) also exhibited promising antiviral activity in cell-based assays. Our results demonstrate the efficacy of our screening strategy, which can lead to the rapid discovery of drug leads with clinical potential in response to new infectious diseases for which no specific drugs or vaccines are available.


Subject(s)
Betacoronavirus/chemistry , Cysteine Endopeptidases/chemistry , Drug Discovery/methods , Models, Molecular , Protease Inhibitors/chemistry , Viral Nonstructural Proteins/antagonists & inhibitors , Viral Nonstructural Proteins/chemistry , Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Betacoronavirus/drug effects , Cells, Cultured/virology , Coronavirus Infections/enzymology , Coronavirus Infections/virology , Drug Design , Drug Evaluation, Preclinical , Humans , Pandemics , Pneumonia, Viral/enzymology , Pneumonia, Viral/virology , Protease Inhibitors/pharmacology , Protein Structure, Tertiary
20.
Indian J Med Res ; 151(2 & 3): 200-209, 2020.
Article in English | MEDLINE | ID: covidwho-32582

ABSTRACT

Background & objectives: Since December 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has globally affected 195 countries. In India, suspected cases were screened for SARS-CoV-2 as per the advisory of the Ministry of Health and Family Welfare. The objective of this study was to characterize SARS-CoV-2 sequences from three identified positive cases as on February 29, 2020. Methods: Throat swab/nasal swab specimens for a total of 881 suspected cases were screened by E gene and confirmed by RdRp (1), RdRp (2) and N gene real-time reverse transcription-polymerase chain reactions and next-generation sequencing. Phylogenetic analysis, molecular characterization and prediction of B- and T-cell epitopes for Indian SARS-CoV-2 sequences were undertaken. Results: Three cases with a travel history from Wuhan, China, were confirmed positive for SARS-CoV-2. Almost complete (29,851 nucleotides) genomes of case 1, case 3 and a fragmented genome for case 2 were obtained. The sequences of Indian SARS-CoV-2 though not identical showed high (~99.98%) identity with Wuhan seafood market pneumonia virus (accession number: NC 045512). Phylogenetic analysis showed that the Indian sequences belonged to different clusters. Predicted linear B-cell epitopes were found to be concentrated in the S1 domain of spike protein, and a conformational epitope was identified in the receptor-binding domain. The predicted T-cell epitopes showed broad human leucocyte antigen allele coverage of A and B supertypes predominant in the Indian population. Interpretation & conclusions: The two SARS-CoV-2 sequences obtained from India represent two different introductions into the country. The genetic heterogeneity is as noted globally. The identified B- and T-cell epitopes may be considered suitable for future experiments towards the design of vaccines and diagnostics. Continuous monitoring and analysis of the sequences of new cases from India and the other affected countries would be vital to understand the genetic evolution and rates of substitution of the SARS-CoV-2.


Subject(s)
Betacoronavirus/genetics , Genome, Viral , Coronavirus Infections , Epitopes, B-Lymphocyte/genetics , Epitopes, T-Lymphocyte/genetics , Humans , India , Models, Molecular , Pandemics , Phylogeny , Pneumonia, Viral , Protein Structure, Tertiary , RNA, Viral/genetics , Reverse Transcriptase Polymerase Chain Reaction , Spike Glycoprotein, Coronavirus/genetics
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