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1.
Epidemiol Infect ; 150: e128, 2022 06 20.
Article in English | MEDLINE | ID: covidwho-1900390

ABSTRACT

During the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) intracellular life-cycle, two large polyproteins, pp1a and pp1ab, are produced. Processing of these by viral cysteine proteases, the papain-like protease (PLpro) and the chymotrypsin-like 3C-like protease (3CL-pro) release non-structural proteins necessary for the establishment of the viral replication and transcription complex (RTC), crucial for viral replication. Hence, these proteases are considered prime targets against which anti-coronavirus disease 2019 (COVID-19) drugs could be developed. Here, we describe the expression of a highly soluble and functionally active recombinant 3CL-pro using Escherichia coli BL21 cells. We show that the enzyme functions in a dimeric form and exhibits an unexpected inhibitory profile because its activity is potently blocked by serine rather than cysteine protease inhibitors. In addition, we assessed the ability of our 3CL-pro to function as a carrier for the receptor binding domain (RBD) of the Spike protein. The co-expressed chimeric protein, 3CLpro-RBD, did not exhibit 3CL-pro activity, but its enhanced solubility made purification easier and improved RBD antigenicity when tested against serum from vaccinated individuals in ELISAs. Chimeric proteins containing the 3CL-pro could represent an innovative approach to developing new COVID-19 vaccines.


Subject(s)
COVID-19 , SARS-CoV-2 , Antiviral Agents/pharmacology , COVID-19 Vaccines , Coronavirus 3C Proteases , Cysteine Endopeptidases/chemistry , Cysteine Endopeptidases/genetics , Cysteine Endopeptidases/metabolism , Humans , Peptide Hydrolases , SARS-CoV-2/genetics
2.
Virol Sin ; 37(3): 437-444, 2022 Jun.
Article in English | MEDLINE | ID: covidwho-1815255

ABSTRACT

The coronavirus 3C-like (3CL) protease, a cysteine protease, plays an important role in viral infection and immune escape. However, there is still a lack of effective tools for determining the cleavage sites of the 3CL protease. This study systematically investigated the diversity of the cleavage sites of the coronavirus 3CL protease on the viral polyprotein, and found that the cleavage motif were highly conserved for viruses in the genera of Alphacoronavirus, Betacoronavirus and Gammacoronavirus. Strong residue preferences were observed at the neighboring positions of the cleavage sites. A random forest (RF) model was built to predict the cleavage sites of the coronavirus 3CL protease based on the representation of residues in cleavage motifs by amino acid indexes, and the model achieved an AUC of 0.96 in cross-validations. The RF model was further tested on an independent test dataset which were composed of cleavage sites on 99 proteins from multiple coronavirus hosts. It achieved an AUC of 0.95 and predicted correctly 80% of the cleavage sites. Then, 1,352 human proteins were predicted to be cleaved by the 3CL protease by the RF model. These proteins were enriched in several GO terms related to the cytoskeleton, such as the microtubule, actin and tubulin. Finally, a webserver named 3CLP was built to predict the cleavage sites of the coronavirus 3CL protease based on the RF model. Overall, the study provides an effective tool for identifying cleavage sites of the 3CL protease and provides insights into the molecular mechanism underlying the pathogenicity of coronaviruses.


Subject(s)
Coronavirus Infections , Coronavirus , Algorithms , Coronavirus/metabolism , Cysteine Endopeptidases/chemistry , Cysteine Endopeptidases/genetics , Cysteine Endopeptidases/metabolism , Humans , Machine Learning , Peptide Hydrolases/metabolism , Protease Inhibitors , Viral Proteins/metabolism
3.
Signal Transduct Target Ther ; 5(1): 221, 2020 10 06.
Article in English | MEDLINE | ID: covidwho-1387195
4.
Sheng Wu Gong Cheng Xue Bao ; 37(4): 1334-1345, 2021 Apr 25.
Article in Chinese | MEDLINE | ID: covidwho-1209675

ABSTRACT

The main protease (Mpro) of SARS-CoV-2 is a highly conserved and mutation-resistant coronaviral enzyme, which plays a pivotal role in viral replication, making it an ideal target for the development of novel broad-spectrum anti-coronaviral drugs. In this study, a codon-optimized Mpro gene was cloned into pET-21a and pET-28a expression vectors. The recombinant plasmids were transformed into E. coli Rosetta(DE3) competent cells and the expression conditions were optimized. The highly expressed recombinant proteins, Mpro and Mpro-28, were purified by HisTrapTM chelating column and its proteolytic activity was determined by a fluorescence resonance energy transfer (FRET) assay. The FRET assay showed that Mpro exhibits a desirable proteolytic activity (25 000 U/mg), with Km and kcat values of 11.68 µmol/L and 0.037/s, respectively. The specific activity of Mpro is 25 times that of Mpro-28, a fusion protein carrying a polyhistidine tag at the N and C termini, indicating additional residues at the N terminus of Mpro, but not at the C terminus, are detrimental to its proteolytic activity. The preparation of active SARS-CoV-2 Mpro through codon-optimization strategy might facilitate the development of the rapid screening assays for the discovery of broad-spectrum anti-coronaviral drugs targeting Mpro.


Subject(s)
COVID-19 , SARS-CoV-2 , Codon/genetics , Cysteine Endopeptidases/genetics , Escherichia coli/genetics , Humans , Peptide Hydrolases , Viral Nonstructural Proteins/genetics
5.
Virus Res ; 288: 198102, 2020 10 15.
Article in English | MEDLINE | ID: covidwho-1003124

ABSTRACT

Coronavirus disease 2019 (COVID-19) is an infectious disease, caused by a newly emerged highly pathogenic virus called novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Targeting the main protease (Mpro, 3CLpro) of SARS-CoV-2 is an appealing approach for drug development because this enzyme plays a significant role in the viral replication and transcription. The available crystal structures of SARS-CoV-2 Mpro determined in the presence of different ligands and inhibitor-like compounds provide a platform for the quick development of selective inhibitors of SARS-CoV-2 Mpro. In this study, we utilized the structural information of co-crystallized SARS-CoV-2 Mpro for the structure-guided drug discovery of high-affinity inhibitors from the PubChem database. The screened compounds were selected on the basis of their physicochemical properties, drug-likeliness, and strength of affinity to the SARS-CoV-2 Mpro. Finally, we have identified 6-Deaminosinefungin (PubChem ID: 10428963) and UNII-O9H5KY11SV (PubChem ID: 71481120) as potential inhibitors of SARS-CoV-2 Mpro which may be further exploited in drug development to address SARS-CoV-2 pathogenesis. Both compounds are structural analogs of known antivirals, having considerable protease inhibitory potential with improved pharmacological properties. All-atom molecular dynamics simulations suggested SARS-CoV-2 Mpro in complex with these compounds is stable during the simulation period with minimal structural changes. This work provides enough evidence for further implementation of the identified compounds in the development of effective therapeutics of COVID-19.


Subject(s)
Aminoglycosides/chemistry , Antiviral Agents/chemistry , Betacoronavirus/chemistry , Protease Inhibitors/chemistry , Pyrrolidines/chemistry , Viral Nonstructural Proteins/antagonists & inhibitors , Aminoglycosides/metabolism , Antiviral Agents/metabolism , Betacoronavirus/enzymology , COVID-19 , Catalytic Domain , Coronavirus 3C Proteases , Coronavirus Infections/drug therapy , Cysteine Endopeptidases/chemistry , Cysteine Endopeptidases/genetics , Cysteine Endopeptidases/metabolism , Drug Discovery , Gene Expression , Humans , Molecular Docking Simulation , Molecular Dynamics Simulation , Pandemics , Pneumonia, Viral/drug therapy , Protease Inhibitors/metabolism , Protein Binding , Protein Conformation, alpha-Helical , Protein Conformation, beta-Strand , Protein Interaction Domains and Motifs , Pyrrolidines/metabolism , SARS-CoV-2 , Substrate Specificity , Sulfonic Acids , Thermodynamics , User-Computer Interface , Viral Nonstructural Proteins/chemistry , Viral Nonstructural Proteins/genetics , Viral Nonstructural Proteins/metabolism
6.
Nat Commun ; 11(1): 5877, 2020 11 18.
Article in English | MEDLINE | ID: covidwho-933685

ABSTRACT

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the pathogen that causes the disease COVID-19, produces replicase polyproteins 1a and 1ab that contain, respectively, 11 or 16 nonstructural proteins (nsp). Nsp5 is the main protease (Mpro) responsible for cleavage at eleven positions along these polyproteins, including at its own N- and C-terminal boundaries, representing essential processing events for subsequent viral assembly and maturation. We have determined X-ray crystallographic structures of this cysteine protease in its wild-type free active site state at 1.8 Å resolution, in its acyl-enzyme intermediate state with the native C-terminal autocleavage sequence at 1.95 Å resolution and in its product bound state at 2.0 Å resolution by employing an active site mutation (C145A). We characterize the stereochemical features of the acyl-enzyme intermediate including critical hydrogen bonding distances underlying catalysis in the Cys/His dyad and oxyanion hole. We also identify a highly ordered water molecule in a position compatible for a role as the deacylating nucleophile in the catalytic mechanism and characterize the binding groove conformational changes and dimerization interface that occur upon formation of the acyl-enzyme. Collectively, these crystallographic snapshots provide valuable mechanistic and structural insights for future antiviral therapeutic development including revised molecular docking strategies based on Mpro inhibition.


Subject(s)
Betacoronavirus/enzymology , Cysteine Endopeptidases/chemistry , Viral Nonstructural Proteins/chemistry , Betacoronavirus/chemistry , Binding Sites , Catalytic Domain , Coronavirus 3C Proteases , Crystallography, X-Ray , Cysteine Endopeptidases/genetics , Cysteine Endopeptidases/metabolism , Dimerization , Humans , Models, Molecular , Mutation , Protease Inhibitors/metabolism , Protein Conformation , SARS-CoV-2 , Substrate Specificity , Viral Nonstructural Proteins/antagonists & inhibitors , Viral Nonstructural Proteins/genetics , Viral Nonstructural Proteins/metabolism
7.
J Chem Inf Model ; 60(10): 5080-5102, 2020 10 26.
Article in English | MEDLINE | ID: covidwho-889114

ABSTRACT

A new coronavirus (SARS-CoV-2) is a global threat to world health and economy. Its dimeric main protease (Mpro), which is required for the proteolytic cleavage of viral precursor proteins, is a good candidate for drug development owing to its conservation and the absence of a human homolog. Improving our understanding of Mpro behavior can accelerate the discovery of effective therapies to reduce mortality. All-atom molecular dynamics (MD) simulations (100 ns) of 50 mutant Mpro dimers obtained from filtered sequences from the GISAID database were analyzed using root-mean-square deviation, root-mean-square fluctuation, Rg, averaged betweenness centrality, and geometry calculations. The results showed that SARS-CoV-2 Mpro essentially behaves in a similar manner to its SAR-CoV homolog. However, we report the following new findings from the variants: (1) Residues GLY15, VAL157, and PRO184 have mutated more than once in SARS CoV-2; (2) the D48E variant has lead to a novel "TSEEMLN"" loop at the binding pocket; (3) inactive apo Mpro does not show signs of dissociation in 100 ns MD; (4) a non-canonical pose for PHE140 widens the substrate binding surface; (5) dual allosteric pockets coinciding with various stabilizing and functional components of the substrate binding pocket were found to display correlated compaction dynamics; (6) high betweenness centrality values for residues 17 and 128 in all Mpro samples suggest their high importance in dimer stability-one such consequence has been observed for the M17I mutation whereby one of the N-fingers was highly unstable. (7) Independent coarse-grained Monte Carlo simulations suggest a relationship between the rigidity/mutability and enzymatic function. Our entire approach combining database preparation, variant retrieval, homology modeling, dynamic residue network (DRN), relevant conformation retrieval from 1-D kernel density estimates from reaction coordinates to other existing approaches of structural analysis, and data visualization within the coronaviral Mpro is also novel and is applicable to other coronaviral proteins.


Subject(s)
Betacoronavirus/genetics , Coronavirus Infections/virology , Cysteine Endopeptidases/genetics , Pneumonia, Viral/virology , Point Mutation , Viral Nonstructural Proteins/genetics , Betacoronavirus/chemistry , Binding Sites , COVID-19 , Coronavirus 3C Proteases , Coronavirus Infections/epidemiology , Cysteine Endopeptidases/chemistry , Humans , Molecular Dynamics Simulation , Mutation , Pandemics , Pneumonia, Viral/epidemiology , Protein Conformation , Protein Multimerization , SARS-CoV-2 , Viral Nonstructural Proteins/chemistry
8.
Sci Adv ; 6(42)2020 10.
Article in English | MEDLINE | ID: covidwho-873433

ABSTRACT

Viral papain-like cysteine protease (PLpro, NSP3) is essential for SARS-CoV-2 replication and represents a promising target for the development of antiviral drugs. Here, we used a combinatorial substrate library and performed comprehensive activity profiling of SARS-CoV-2 PLpro. On the scaffold of the best hits from positional scanning, we designed optimal fluorogenic substrates and irreversible inhibitors with a high degree of selectivity for SARS PLpro. We determined crystal structures of two of these inhibitors in complex with SARS-CoV-2 PLpro that reveals their inhibitory mechanisms and provides a molecular basis for the observed substrate specificity profiles. Last, we demonstrate that SARS-CoV-2 PLpro harbors deISGylating activity similar to SARSCoV-1 PLpro but its ability to hydrolyze K48-linked Ub chains is diminished, which our sequence and structure analysis provides a basis for. Together, this work has revealed the molecular rules governing PLpro substrate specificity and provides a framework for development of inhibitors with potential therapeutic value or drug repurposing.


Subject(s)
Betacoronavirus/enzymology , Drug Design , Protease Inhibitors/chemistry , Viral Nonstructural Proteins/antagonists & inhibitors , Amino Acid Sequence , Betacoronavirus/isolation & purification , Binding Sites , COVID-19 , Catalytic Domain , Coronavirus 3C Proteases , Coronavirus Infections/pathology , Coronavirus Infections/virology , Crystallography, X-Ray , Cysteine Endopeptidases/genetics , Cysteine Endopeptidases/metabolism , Humans , Kinetics , Molecular Dynamics Simulation , Oligopeptides/chemistry , Oligopeptides/metabolism , Pandemics , Pneumonia, Viral/pathology , Pneumonia, Viral/virology , Protease Inhibitors/metabolism , Recombinant Proteins/biosynthesis , Recombinant Proteins/chemistry , Recombinant Proteins/isolation & purification , SARS-CoV-2 , Substrate Specificity , Ubiquitins/metabolism , Viral Nonstructural Proteins/genetics , Viral Nonstructural Proteins/metabolism
9.
Biochem J ; 477(5): 1009-1019, 2020 03 13.
Article in English | MEDLINE | ID: covidwho-827308

ABSTRACT

Severe acute respiratory syndrome coronavirus is the causative agent of a respiratory disease with a high case fatality rate. During the formation of the coronaviral replication/transcription complex, essential steps include processing of the conserved polyprotein nsp7-10 region by the main protease Mpro and subsequent complex formation of the released nsp's. Here, we analyzed processing of the coronavirus nsp7-10 region using native mass spectrometry showing consumption of substrate, rise and fall of intermediate products and complexation. Importantly, there is a clear order of cleavage efficiencies, which is influenced by the polyprotein tertiary structure. Furthermore, the predominant product is an nsp7+8(2 : 2) hetero-tetramer with nsp8 scaffold. In conclusion, native MS, opposed to other methods, can expose the processing dynamics of viral polyproteins and the landscape of protein interactions in one set of experiments. Thereby, new insights into protein interactions, essential for generation of viral progeny, were provided, with relevance for development of antivirals.


Subject(s)
RNA-Binding Proteins/genetics , Sequence Alignment/methods , Viral Nonstructural Proteins/genetics , Viral Regulatory and Accessory Proteins/genetics , Coronavirus 3C Proteases , Coronavirus Infections/genetics , Coronavirus RNA-Dependent RNA Polymerase , Cysteine Endopeptidases/chemistry , Cysteine Endopeptidases/genetics , Fluorescence Resonance Energy Transfer , Protein Structure, Secondary , RNA-Binding Proteins/chemistry , Viral Nonstructural Proteins/chemistry , Viral Regulatory and Accessory Proteins/chemistry , Virus Replication/physiology
10.
Acta Crystallogr F Struct Biol Commun ; 76(Pt 10): 483-487, 2020 Oct 01.
Article in English | MEDLINE | ID: covidwho-817571

ABSTRACT

The replication of SARS-CoV-2 produces two large polyproteins, pp1a and pp1ab, that are inactive until cleavage by the viral chymotrypsin-like cysteine protease enzyme (3CL Mpro) into a series of smaller functional proteins. At the heart of 3CL Mpro is an unusual catalytic dyad formed by the side chains of His41 and Cys145 and a coordinated water molecule. The catalytic mechanism by which the enzyme operates is still unknown, as crucial information on the protonation states within the active site is unclear. To experimentally determine the protonation states of the catalytic site and of the other residues in the substrate-binding cavity, and to visualize the hydrogen-bonding networks throughout the enzyme, room-temperature neutron and X-ray data were collected from a large H/D-exchanged crystal of ligand-free (apo) 3CL Mpro.


Subject(s)
Betacoronavirus/enzymology , Coronavirus Infections/virology , Cysteine Endopeptidases/chemistry , Pneumonia, Viral/virology , Viral Nonstructural Proteins/chemistry , Betacoronavirus/chemistry , Betacoronavirus/genetics , COVID-19 , Catalytic Domain , Coronavirus 3C Proteases , Crystallography, X-Ray , Cysteine Endopeptidases/genetics , Humans , Models, Molecular , Neutron Diffraction , Pandemics , Protein Conformation , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , SARS-CoV-2 , Temperature , Viral Nonstructural Proteins/genetics
11.
PLoS One ; 15(9): e0238344, 2020.
Article in English | MEDLINE | ID: covidwho-742540

ABSTRACT

A novel severe acute respiratory syndrome-related coronavirus-2 (SARS-CoV-2) causing COVID-19 pandemic in humans, recently emerged and has exported in more than 200 countries as a result of rapid spread. In this study, we have made an attempt to investigate the SARS-CoV-2 genome reported from 13 different countries, identification of mutations in major coronavirus proteins of these different SARS-CoV-2 genomes and compared with SARS-CoV. These thirteen complete genome sequences of SARS-CoV-2 showed high identity (>99%) to each other, while they shared 82% identity with SARS-CoV. Here, we performed a very systematic mutational analysis of SARS-CoV-2 genomes from different geographical locations, which enabled us to identify numerous unique features of this viral genome. This includes several important country-specific unique mutations in the major proteins of SARS-CoV-2 namely, replicase polyprotein, spike glycoprotein, envelope protein and nucleocapsid protein. Indian strain showed mutation in spike glycoprotein at R408I and in replicase polyprotein at I671T, P2144S and A2798V,. While the spike protein of Spain & South Korea carried F797C and S221W mutation, respectively. Likewise, several important country specific mutations were analyzed. The effect of mutations of these major proteins were also investigated using various in silico approaches. Main protease (Mpro), the therapeutic target protein of SARS with maximum reported inhibitors, was thoroughly investigated and the effect of mutation on the binding affinity and structural dynamics of Mpro was studied. It was found that the R60C mutation in Mpro affects the protein dynamics, thereby, affecting the binding of inhibitor within its active site. The implications of mutation on structural characteristics were determined. The information provided in this manuscript holds great potential in further scientific research towards the design of potential vaccine candidates/small molecular inhibitor against COVID19.


Subject(s)
Betacoronavirus/genetics , Cysteine Endopeptidases/genetics , Genome, Viral , Mutation , Nucleocapsid Proteins/genetics , Spike Glycoprotein, Coronavirus/genetics , Viral Envelope Proteins/genetics , Viral Nonstructural Proteins/genetics , Betacoronavirus/classification , Coronavirus 3C Proteases , Coronavirus Envelope Proteins , Coronavirus Nucleocapsid Proteins , Cysteine Endopeptidases/chemistry , Genetic Variation , Molecular Dynamics Simulation , Nucleocapsid Proteins/chemistry , Phosphoproteins , Phylogeny , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/chemistry , Viral Envelope Proteins/chemistry , Viral Nonstructural Proteins/chemistry
12.
Molecules ; 25(17)2020 Aug 28.
Article in English | MEDLINE | ID: covidwho-740497

ABSTRACT

A pandemic caused by the novel coronavirus (SARS-CoV-2 or COVID-19) began in December 2019 in Wuhan, China, and the number of newly reported cases continues to increase. More than 19.7 million cases have been reported globally and about 728,000 have died as of this writing (10 August 2020). Recently, it has been confirmed that the SARS-CoV-2 main protease (Mpro) enzyme is responsible not only for viral reproduction but also impedes host immune responses. The Mpro provides a highly favorable pharmacological target for the discovery and design of inhibitors. Currently, no specific therapies are available, and investigations into the treatment of COVID-19 are lacking. Therefore, herein, we analyzed the bioactive phytocompounds isolated by gas chromatography-mass spectroscopy (GC-MS) from Tinospora crispa as potential COVID-19 Mpro inhibitors, using molecular docking study. Our analyses unveiled that the top nine hits might serve as potential anti-SARS-CoV-2 lead molecules, with three of them exerting biological activity and warranting further optimization and drug development to combat COVID-19.


Subject(s)
Antiviral Agents/chemistry , Betacoronavirus/chemistry , Phytochemicals/chemistry , Protease Inhibitors/chemistry , Tinospora/chemistry , Viral Nonstructural Proteins/antagonists & inhibitors , Antiviral Agents/classification , Antiviral Agents/isolation & purification , Antiviral Agents/pharmacology , Betacoronavirus/drug effects , Betacoronavirus/enzymology , COVID-19 , Catalytic Domain , Coronavirus 3C Proteases , Coronavirus Infections/drug therapy , Cysteine Endopeptidases/chemistry , Cysteine Endopeptidases/genetics , Cysteine Endopeptidases/metabolism , Drug Discovery , Gas Chromatography-Mass Spectrometry , Gene Expression , Humans , Kinetics , Molecular Docking Simulation , Pandemics , Phytochemicals/classification , Phytochemicals/isolation & purification , Phytochemicals/pharmacology , Pneumonia, Viral/drug therapy , Protease Inhibitors/classification , Protease Inhibitors/isolation & purification , Protease Inhibitors/pharmacology , Protein Binding , Protein Interaction Domains and Motifs , Protein Structure, Secondary , SARS-CoV-2 , Substrate Specificity , Thermodynamics , Viral Nonstructural Proteins/chemistry , Viral Nonstructural Proteins/genetics , Viral Nonstructural Proteins/metabolism
13.
Molecules ; 25(17)2020 Aug 27.
Article in English | MEDLINE | ID: covidwho-737517

ABSTRACT

Three types of new coronaviruses (CoVs) have been identified recently as the causative viruses for the severe pneumonia-like respiratory illnesses, severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), and corona-virus disease 2019 (COVID-19). Neither therapeutic agents nor vaccines have been developed to date, which is a major drawback in controlling the present global pandemic of COVID-19 caused by SARS coronavirus 2 (SARS-CoV-2) and has resulted in more than 20,439,814 cases and 744,385 deaths. Each of the 3C-like (3CL) proteases of the three CoVs is essential for the proliferation of the CoVs, and an inhibitor of the 3CL protease (3CLpro) is thought to be an ideal therapeutic agent against SARS, MERS, or COVID-19. Among these, SARS-CoV is the first corona-virus isolated and has been studied in detail since the first pandemic in 2003. This article briefly reviews a series of studies on SARS-CoV, focusing on the development of inhibitors for the SARS-CoV 3CLpro based on molecular interactions with the 3CL protease. Our recent approach, based on the structure-based rational design of a novel scaffold for SARS-CoV 3CLpro inhibitor, is also included. The achievements summarized in this short review would be useful for the design of a variety of novel inhibitors for corona-viruses, including SARS-CoV-2.


Subject(s)
Antiviral Agents/chemistry , Betacoronavirus/chemistry , Middle East Respiratory Syndrome Coronavirus/pathogenicity , Protease Inhibitors/chemistry , SARS Virus/pathogenicity , Viral Nonstructural Proteins/antagonists & inhibitors , Antiviral Agents/classification , Antiviral Agents/therapeutic use , Betacoronavirus/drug effects , Betacoronavirus/enzymology , COVID-19 , Catalytic Domain , Coronavirus 3C Proteases , Coronavirus Infections/drug therapy , Crystallography, X-Ray , Cysteine Endopeptidases/chemistry , Cysteine Endopeptidases/genetics , Cysteine Endopeptidases/metabolism , Humans , Kinetics , Middle East Respiratory Syndrome Coronavirus/genetics , Middle East Respiratory Syndrome Coronavirus/metabolism , Molecular Docking Simulation , Pandemics , Pneumonia, Viral/drug therapy , Protease Inhibitors/classification , Protease Inhibitors/therapeutic use , Protein Binding , Protein Conformation, alpha-Helical , Protein Conformation, beta-Strand , Protein Interaction Domains and Motifs , SARS Virus/genetics , SARS Virus/metabolism , SARS-CoV-2 , Severe Acute Respiratory Syndrome/drug therapy , Substrate Specificity , Thermodynamics , Viral Nonstructural Proteins/chemistry , Viral Nonstructural Proteins/genetics , Viral Nonstructural Proteins/metabolism
14.
Molecules ; 25(17)2020 Aug 23.
Article in English | MEDLINE | ID: covidwho-727434

ABSTRACT

The SARS-CoV-2 outbreak caused an unprecedented global public health threat, having a high transmission rate with currently no drugs or vaccines approved. An alternative powerful additional approach to counteract COVID-19 is in silico drug repurposing. The SARS-CoV-2 main protease is essential for viral replication and an attractive drug target. In this study, we used the virtual screening protocol with both long-range and short-range interactions to select candidate SARS-CoV-2 main protease inhibitors. First, the Informational spectrum method applied for small molecules was used for searching the Drugbank database and further followed by molecular docking. After in silico screening of drug space, we identified 57 drugs as potential SARS-CoV-2 main protease inhibitors that we propose for further experimental testing.


Subject(s)
Antiviral Agents/chemistry , Betacoronavirus/drug effects , Cysteine Endopeptidases/chemistry , Mezlocillin/chemistry , Protease Inhibitors/chemistry , Raltegravir Potassium/chemistry , Viral Nonstructural Proteins/chemistry , Allosteric Site , Antiviral Agents/pharmacology , Betacoronavirus/enzymology , Betacoronavirus/pathogenicity , COVID-19 , Catalytic Domain , Coronavirus 3C Proteases , Coronavirus Infections/drug therapy , Coronavirus Infections/enzymology , Coronavirus Infections/virology , Cysteine Endopeptidases/genetics , Cysteine Endopeptidases/metabolism , Drug Repositioning , Gene Expression , High-Throughput Screening Assays , Humans , Mezlocillin/pharmacology , Molecular Docking Simulation , Pandemics , Pneumonia, Viral/drug therapy , Pneumonia, Viral/enzymology , Pneumonia, Viral/virology , Protease Inhibitors/pharmacology , Protein Binding , Protein Conformation, alpha-Helical , Protein Conformation, beta-Strand , Protein Interaction Domains and Motifs , Raltegravir Potassium/pharmacology , SARS-CoV-2 , Thermodynamics , Viral Nonstructural Proteins/antagonists & inhibitors , Viral Nonstructural Proteins/genetics , Viral Nonstructural Proteins/metabolism , Virus Replication/drug effects
15.
mBio ; 11(4)2020 08 20.
Article in English | MEDLINE | ID: covidwho-724620

ABSTRACT

We assessed various newly generated compounds that target the main protease (Mpro) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and various previously known compounds reportedly active against SARS-CoV-2, employing RNA quantitative PCR (RNA-qPCR), cytopathicity assays, and immunocytochemistry. Here, we show that two indole-chloropyridinyl-ester derivatives, GRL-0820 and GRL-0920, exerted potent activity against SARS-CoV-2 in cell-based assays performed using VeroE6 cells and TMPRSS2-overexpressing VeroE6 cells. While GRL-0820 and the nucleotide analog remdesivir blocked SARS-CoV-2 infection, viral breakthrough occurred. No significant anti-SARS-CoV-2 activity was found for several compounds reportedly active against SARS-CoV-2 such as lopinavir, nelfinavir, nitazoxanide, favipiravir, and hydroxychroloquine. In contrast, GRL-0920 exerted potent activity against SARS-CoV-2 (50% effective concentration [EC50] = 2.8 µM) and dramatically reduced the infectivity, replication, and cytopathic effect of SARS-CoV-2 without significant toxicity as examined with immunocytochemistry. Structural modeling shows that indole and chloropyridinyl of the derivatives interact with two catalytic dyad residues of Mpro, Cys145 and His41, resulting in covalent bonding, which was verified using high-performance liquid chromatography-mass spectrometry (HPLC/MS), suggesting that the indole moiety is critical for the anti-SARS-CoV-2 activity of the derivatives. GRL-0920 might serve as a potential therapeutic for coronavirus disease 2019 (COVID-19) and might be optimized to generate more-potent anti-SARS-CoV-2 compounds.IMPORTANCE Targeting the main protease (Mpro) of SARS-CoV-2, we identified two indole-chloropyridinyl-ester derivatives, GRL-0820 and GRL-0920, active against SARS-CoV-2, employing RNA-qPCR and immunocytochemistry and show that the two compounds exerted potent activity against SARS-CoV-2. While GRL-0820 and remdesivir blocked SARS-CoV-2 infection, viral breakthrough occurred as examined with immunocytochemistry. In contrast, GRL-0920 completely blocked the infectivity and cytopathic effect of SARS-CoV-2 without significant toxicity. Structural modeling showed that indole and chloropyridinyl of the derivatives interacted with two catalytic dyad residues of Mpro, Cys145 and His41, resulting in covalent bonding, which was verified using HPLC/MS. The present data should shed light on the development of therapeutics for COVID-19, and optimization of GRL-0920 based on the present data is essential to develop more-potent anti-SARS-CoV-2 compounds for treating COVID-19.


Subject(s)
Antiviral Agents/pharmacology , Betacoronavirus/drug effects , Coronavirus Infections/drug therapy , Indoles/pharmacology , Pneumonia, Viral/drug therapy , Amino Acid Sequence , Animals , Betacoronavirus/enzymology , COVID-19 , Chlorocebus aethiops , Chloroquine/pharmacology , Coronavirus 3C Proteases , Coronavirus Infections/virology , Cysteine Endopeptidases/chemistry , Cysteine Endopeptidases/genetics , Cysteine Endopeptidases/metabolism , Indoles/chemistry , Indoles/therapeutic use , Models, Molecular , Pandemics , Pneumonia, Viral/virology , SARS-CoV-2 , Vero Cells , Viral Nonstructural Proteins/antagonists & inhibitors , Viral Nonstructural Proteins/chemistry , Viral Nonstructural Proteins/genetics , Viral Nonstructural Proteins/metabolism
16.
Antimicrob Agents Chemother ; 64(9)2020 08 20.
Article in English | MEDLINE | ID: covidwho-646490

ABSTRACT

The coronavirus (CoV) disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome CoV-2 (SARS-CoV-2) is a health threat worldwide. Viral main protease (Mpro, also called 3C-like protease [3CLpro]) is a therapeutic target for drug discovery. Herein, we report that GC376, a broad-spectrum inhibitor targeting Mpro in the picornavirus-like supercluster, is a potent inhibitor for the Mpro encoded by SARS-CoV-2, with a half-maximum inhibitory concentration (IC50) of 26.4 ± 1.1 nM. In this study, we also show that GC376 inhibits SARS-CoV-2 replication with a half-maximum effective concentration (EC50) of 0.91 ± 0.03 µM. Only a small portion of SARS-CoV-2 Mpro was covalently modified in the excess of GC376 as evaluated by mass spectrometry analysis, indicating that improved inhibitors are needed. Subsequently, molecular docking analysis revealed that the recognition and binding groups of GC376 within the active site of SARS-CoV-2 Mpro provide important new information for the optimization of GC376. Given that sufficient safety and efficacy data are available for GC376 as an investigational veterinary drug, expedited development of GC376, or its optimized analogues, for treatment of SARS-CoV-2 infection in human is recommended.


Subject(s)
Antiviral Agents/chemistry , Betacoronavirus/drug effects , Cysteine Endopeptidases/chemistry , Protease Inhibitors/chemistry , Pyrrolidines/chemistry , Viral Nonstructural Proteins/chemistry , Amino Acid Motifs , Animals , Antiviral Agents/pharmacology , Betacoronavirus/pathogenicity , Catalytic Domain , Chlorocebus aethiops , Coronavirus 3C Proteases , Cysteine Endopeptidases/genetics , Cysteine Endopeptidases/metabolism , Gene Expression , Molecular Docking Simulation , Protease Inhibitors/pharmacology , Protein Binding , Protein Conformation, alpha-Helical , Protein Conformation, beta-Strand , Protein Interaction Domains and Motifs , Pyrrolidines/pharmacology , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , SARS-CoV-2 , Sulfonic Acids , Thermodynamics , Vero Cells , Viral Nonstructural Proteins/antagonists & inhibitors , Viral Nonstructural Proteins/genetics , Viral Nonstructural Proteins/metabolism , Virus Replication/drug effects
17.
Biophys Chem ; 264: 106425, 2020 09.
Article in English | MEDLINE | ID: covidwho-634721

ABSTRACT

The novel SARS-CoV-2 is the etiological agent causing the Coronavirus disease 2019 (COVID-19), which continues to become an inevitable pandemic outbreak. Over a short span of time, the structures of therapeutic target proteins for SARS-CoV-2 were identified based on the homology modelled structure of similar SARS-CoV transmission of 2003. Since the onset of the disease, the research community has been looking for a potential drug lead. Out of all the known resolved structures related to SARS-CoV, Main protease (Mpro) is considered an attractive anti-viral drug target on the grounds of its role in viral replication and probable non-interactive competency to bind to any viral host protein. To the best of our knowledge, till date only one compound has been identified and tested in-vivo as a potent inhibitor of Mpro protein, addressed as N3 (PubChem Compound CID: 6323191) and is known to bind irreversibly to Mpro suppressing its activity. Using computational approach, we intend to identify a probable natural fungal metabolite to interact and inhibit Mpro. After screening various small molecules for molecular docking and dynamics simulation, we propose Pyranonigrin A, a secondary fungal metabolite to possess potent inhibitory potential against the Main protease (Mpro) expressed in SARS-CoV-2 virus.


Subject(s)
Antiviral Agents/chemistry , Betacoronavirus/enzymology , Protease Inhibitors/chemistry , Pyrones/chemistry , Pyrroles/chemistry , Viral Nonstructural Proteins/antagonists & inhibitors , Betacoronavirus/pathogenicity , Binding Sites , Coronavirus 3C Proteases , Crystallography, X-Ray , Cysteine Endopeptidases/chemistry , Cysteine Endopeptidases/genetics , Cysteine Endopeptidases/metabolism , Drug Discovery , Gene Expression , Hydrogen Bonding , Molecular Docking Simulation , Molecular Dynamics Simulation , Protein Binding , Protein Conformation, alpha-Helical , Protein Conformation, beta-Strand , Protein Interaction Domains and Motifs , SARS-CoV-2 , Sequence Homology, Amino Acid , Thermodynamics , Viral Nonstructural Proteins/chemistry , Viral Nonstructural Proteins/genetics , Viral Nonstructural Proteins/metabolism
18.
Genes (Basel) ; 11(6)2020 06 09.
Article in English | MEDLINE | ID: covidwho-591861

ABSTRACT

The severe respiratory disease COVID-19 was initially reported in Wuhan, China, in December 2019, and spread into many provinces from Wuhan. The corresponding pathogen was soon identified as a novel coronavirus named SARS-CoV-2 (formerly, 2019-nCoV). As of 2 May, 2020, over 3 million COVID-19 cases had been confirmed, and 235,290 deaths had been reported globally, and the numbers are still increasing. It is important to understand the phylogenetic relationship between SARS-CoV-2 and known coronaviruses, and to identify its hosts for preventing the next round of emergency outbreak. In this study, we employ an effective alignment-free approach, the Natural Vector method, to analyze the phylogeny and classify the coronaviruses based on genomic and protein data. Our results show that SARS-CoV-2 is closely related to, but distinct from the SARS-CoV branch. By analyzing the genetic distances from the SARS-CoV-2 strain to the coronaviruses residing in animal hosts, we establish that the most possible transmission path originates from bats to pangolins to humans.


Subject(s)
Betacoronavirus/genetics , Coronavirus Infections/transmission , Coronavirus/genetics , Models, Biological , Pneumonia, Viral/transmission , Animals , Betacoronavirus/classification , COVID-19 , Chiroptera/virology , Coronavirus/classification , Coronavirus 3C Proteases , Coronavirus Infections/virology , Cysteine Endopeptidases/chemistry , Cysteine Endopeptidases/genetics , Disease Outbreaks , Disease Reservoirs , Humans , Mammals/classification , Mammals/virology , Pandemics , Phylogeny , Pneumonia, Viral/virology , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Viral Nonstructural Proteins/chemistry , Viral Nonstructural Proteins/genetics
19.
Interdiscip Sci ; 12(3): 368-376, 2020 Sep.
Article in English | MEDLINE | ID: covidwho-459220

ABSTRACT

A novel coronavirus, called 2019-nCoV, was recently found in Wuhan, Hubei Province of China, and now is spreading across China and other parts of the world. Although there are some drugs to treat 2019-nCoV, there is no proper scientific evidence about its activity on the virus. It is of high significance to develop a drug that can combat the virus effectively to save valuable human lives. It usually takes a much longer time to develop a drug using traditional methods. For 2019-nCoV, it is now better to rely on some alternative methods such as deep learning to develop drugs that can combat such a disease effectively since 2019-nCoV is highly homologous to SARS-CoV. In the present work, we first collected virus RNA sequences of 18 patients reported to have 2019-nCoV from the public domain database, translated the RNA into protein sequences, and performed multiple sequence alignment. After a careful literature survey and sequence analysis, 3C-like protease is considered to be a major therapeutic target and we built a protein 3D model of 3C-like protease using homology modeling. Relying on the structural model, we used a pipeline to perform large scale virtual screening by using a deep learning based method to accurately rank/identify protein-ligand interacting pairs developed recently in our group. Our model identified potential drugs for 2019-nCoV 3C-like protease by performing drug screening against four chemical compound databases (Chimdiv, Targetmol-Approved_Drug_Library, Targetmol-Natural_Compound_Library, and Targetmol-Bioactive_Compound_Library) and a database of tripeptides. Through this paper, we provided the list of possible chemical ligands (Meglumine, Vidarabine, Adenosine, D-Sorbitol, D-Mannitol, Sodium_gluconate, Ganciclovir and Chlorobutanol) and peptide drugs (combination of isoleucine, lysine and proline) from the databases to guide the experimental scientists and validate the molecules which can combat the virus in a shorter time.


Subject(s)
Antiviral Agents/pharmacology , Betacoronavirus/drug effects , Coronavirus Infections/drug therapy , Coronavirus Infections/virology , Deep Learning , Drug Evaluation, Preclinical/methods , Pneumonia, Viral/drug therapy , Pneumonia, Viral/virology , Viral Nonstructural Proteins/antagonists & inhibitors , Amino Acid Sequence , Antiviral Agents/chemistry , Betacoronavirus/genetics , COVID-19 , Catalytic Domain , Coronavirus 3C Proteases , Coronavirus Infections/epidemiology , Cysteine Endopeptidases/chemistry , Cysteine Endopeptidases/genetics , Databases, Nucleic Acid , Databases, Pharmaceutical , Drug Design , Drug Evaluation, Preclinical/statistics & numerical data , Humans , Ligands , Models, Molecular , Molecular Dynamics Simulation , Oligopeptides/chemistry , Oligopeptides/pharmacology , Pandemics , Pneumonia, Viral/epidemiology , SARS-CoV-2 , Sequence Alignment , Structural Homology, Protein , User-Computer Interface , Viral Nonstructural Proteins/chemistry , Viral Nonstructural Proteins/genetics
20.
Molecules ; 25(11)2020 May 29.
Article in English | MEDLINE | ID: covidwho-436971

ABSTRACT

The coronavirus disease, COVID-19, caused by the novel coronavirus SARS-CoV-2, which first emerged in Wuhan, China and was made known to the World in December 2019 turned into a pandemic causing more than 126,124 deaths worldwide up to April 16th, 2020. It has 79.5% sequence identity with SARS-CoV-1 and the same strategy for host cell invasion through the ACE-2 surface protein. Since the development of novel drugs is a long-lasting process, researchers look for effective substances among drugs already approved or developed for other purposes. The 3D structure of the SARS-CoV-2 main protease was compared with the 3D structures of seven proteases, which are drug targets, and docking analysis to the SARS-CoV-2 protease structure of thirty four approved and on-trial protease inhibitors was performed. Increased 3D structural similarity between the SARS-CoV-2 main protease, the HCV protease and α-thrombin was found. According to docking analysis the most promising results were found for HCV protease, DPP-4, α-thrombin and coagulation Factor Xa known inhibitors, with several of them exhibiting estimated free binding energy lower than -8.00 kcal/mol and better prediction results than reference compounds. Since some of the compounds are well-tolerated drugs, the promising in silico results may warrant further evaluation for viral anticipation. DPP-4 inhibitors with anti-viral action may be more useful for infected patients with diabetes, while anti-coagulant treatment is proposed in severe SARS-CoV-2 induced pneumonia.


Subject(s)
Anticoagulants/chemistry , Antiviral Agents/chemistry , Betacoronavirus/drug effects , Dipeptidyl-Peptidase IV Inhibitors/chemistry , Protease Inhibitors/chemistry , Viral Nonstructural Proteins/antagonists & inhibitors , Amino Acid Sequence , Anticoagulants/pharmacology , Antiviral Agents/pharmacology , Betacoronavirus/chemistry , Betacoronavirus/enzymology , Betacoronavirus/genetics , Binding Sites , COVID-19 , Coronavirus 3C Proteases , Coronavirus Infections/drug therapy , Cysteine Endopeptidases/chemistry , Cysteine Endopeptidases/genetics , Cysteine Endopeptidases/metabolism , Dipeptidyl Peptidase 4/chemistry , Dipeptidyl Peptidase 4/genetics , Dipeptidyl Peptidase 4/metabolism , Dipeptidyl-Peptidase IV Inhibitors/pharmacology , Factor Xa/chemistry , Factor Xa/genetics , Factor Xa/metabolism , Hepacivirus/chemistry , Hepacivirus/enzymology , Hepacivirus/genetics , Humans , Molecular Docking Simulation , Pandemics , Pneumonia, Viral/drug therapy , Protease Inhibitors/pharmacology , Protein Binding , Protein Conformation , Protein Interaction Domains and Motifs , SARS-CoV-2 , Sequence Alignment , Structural Homology, Protein , Substrate Specificity , Thermodynamics , Thrombin/antagonists & inhibitors , Thrombin/chemistry , Thrombin/genetics , Thrombin/metabolism , Viral Nonstructural Proteins/chemistry , Viral Nonstructural Proteins/genetics , Viral Nonstructural Proteins/metabolism
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