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1.
Appl Biochem Biotechnol ; 194(1): 291-301, 2022 Jan.
Article in English | MEDLINE | ID: covidwho-1748423

ABSTRACT

Corona virus pandemic outbreak also known as COVID-19 has created an imbalance in this world. Scientists have adopted the use of natural or alternative medicines which are consumed mostly as dietary supplements to boost the immune system as herbal remedies. India is famous for traditional medicinal formulations which includes 'Trikadu'-a combination of three acrids, namely Zingiber officinale, Piper nigrum and Piper longum which have antioxidant properties that boost our immune system hence acting as a strong preventive measure. In this study, AutoDock 4.0 was used to study interaction between the phytocompounds of Trikadu with RNA-dependent polymerase protein and enveloped protein of the SARS-CoV-2 virus. Analysis of the results showed that coumarin, coumaperine and bisdemethoxycurcumin showed strong bonding interactions with both the proteins. We can conclude that Trikadu has the potential molecules; hence, it can be incorporated in the diet to boost the immune system as a preventive measure against the virus.


Subject(s)
COVID-19/drug therapy , COVID-19/immunology , Phytotherapy , Plant Preparations/therapeutic use , SARS-CoV-2 , Antioxidants/isolation & purification , Antioxidants/therapeutic use , COVID-19/virology , Computer Simulation , Coronavirus RNA-Dependent RNA Polymerase/chemistry , Coronavirus RNA-Dependent RNA Polymerase/drug effects , Dietary Supplements , Ginger/chemistry , Humans , Immune System/drug effects , India , Ligands , Medicine, Traditional , Molecular Docking Simulation , Phytochemicals/chemistry , Phytochemicals/therapeutic use , Piper/chemistry , Piper nigrum/chemistry , Plant Preparations/isolation & purification , Plants, Medicinal/chemistry , SARS-CoV-2/chemistry , SARS-CoV-2/drug effects , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/drug effects
2.
Virology ; 567: 1-14, 2022 02.
Article in English | MEDLINE | ID: covidwho-1628759

ABSTRACT

The coronavirus nucleocapsid (N) protein comprises two RNA-binding domains connected by a central spacer, which contains a serine- and arginine-rich (SR) region. The SR region engages the largest subunit of the viral replicase-transcriptase, nonstructural protein 3 (nsp3), in an interaction that is essential for efficient initiation of infection by genomic RNA. We carried out an extensive genetic analysis of the SR region of the N protein of mouse hepatitis virus in order to more precisely define its role in RNA synthesis. We further examined the N-nsp3 interaction through construction of nsp3 mutants and by creation of an interspecies N protein chimera. Our results indicate a role for the central spacer as an interaction hub of the N molecule that is partially regulated by phosphorylation. These findings are discussed in relation to the recent discovery that nsp3 forms a molecular pore in the double-membrane vesicles that sequester the coronavirus replicase-transcriptase.


Subject(s)
Coronavirus Nucleocapsid Proteins/metabolism , Intracellular Membranes/metabolism , Viral Replicase Complex Proteins/metabolism , Amino Acid Motifs , Animals , Cell Line , Coronavirus Nucleocapsid Proteins/chemistry , Coronavirus Nucleocapsid Proteins/genetics , Coronavirus RNA-Dependent RNA Polymerase/chemistry , Coronavirus RNA-Dependent RNA Polymerase/genetics , Coronavirus RNA-Dependent RNA Polymerase/metabolism , Mice , Murine hepatitis virus , Mutation , Protein Binding , Protein Domains , RNA, Viral/biosynthesis , Viral Replicase Complex Proteins/chemistry , Viral Replicase Complex Proteins/genetics , Viral Replication Compartments/metabolism
3.
Int J Mol Sci ; 23(1)2022 Jan 04.
Article in English | MEDLINE | ID: covidwho-1613825

ABSTRACT

(1R,5S)-1-Hydroxy-3,6-dioxa-bicyclo[3.2.1]octan-2-one, available by an efficient catalytic pyrolysis of cellulose, has been applied as a chiral building block in the synthesis of seven new nucleoside analogues, with structural modifications on the nucleobase moiety and on the carboxyl- derived unit. The inverted configuration by Mitsunobu reaction used in their synthesis was verified by 2D-NOESY correlations, supported by the optimized structure employing the DFT methods. An in silico screening of these compounds as inhibitors of SARS-CoV-2 RNA-dependent RNA polymerase has been carried out in comparison with both remdesivir, a mono-phosphoramidate prodrug recently approved for COVID-19 treatment, and its ribonucleoside metabolite GS-441524. Drug-likeness prediction and data by docking calculation indicated compound 6 [=(3S,5S)-methyl 5-(hydroxymethyl)-3-(6-(4-methylpiperazin-1-yl)-9H-purin-9-yl)tetrahydrofuran-3-carboxylate] as the best candidate. Furthermore, molecular dynamics simulation showed a stable interaction of structure 6 in RNA-dependent RNA polymerase (RdRp) complex and a lower average atomic fluctuation than GS-441524, suggesting a well accommodation in the RdRp binding pocket.


Subject(s)
Antiviral Agents/chemical synthesis , Cellulose/chemistry , Coronavirus RNA-Dependent RNA Polymerase/antagonists & inhibitors , Nucleosides/chemical synthesis , SARS-CoV-2/enzymology , Adenosine/analogs & derivatives , Adenosine/chemistry , Adenosine/pharmacokinetics , Adenosine Monophosphate/analogs & derivatives , Adenosine Monophosphate/chemistry , Adenosine Monophosphate/pharmacokinetics , Alanine/analogs & derivatives , Alanine/chemistry , Alanine/pharmacokinetics , Antiviral Agents/chemistry , Antiviral Agents/pharmacokinetics , Computational Biology , Coronavirus RNA-Dependent RNA Polymerase/chemistry , Molecular Docking Simulation , Molecular Dynamics Simulation , Nucleosides/chemistry , Nucleosides/pharmacokinetics , Pyrolysis , SARS-CoV-2/drug effects
4.
J Comput Biol ; 28(12): 1228-1247, 2021 12.
Article in English | MEDLINE | ID: covidwho-1545879

ABSTRACT

The detrimental effect of coronavirus disease 2019 (COVID-19) pandemic has manifested itself as a global crisis. Currently, no specific treatment options are available for COVID-19, so therapeutic interventions to tackle the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection must be urgently established. Therefore, cohesive and multidimensional efforts are required to identify new therapies or investigate the efficacy of small molecules and existing drugs against SARS-CoV-2. Since the RNA-dependent RNA Polymerase (RdRP) of SARS-CoV-2 is a promising therapeutic target, this study addresses the identification of antiviral molecules that can specifically target SARS-CoV-2 RdRP. The computational approach of drug development was used to screen the antiviral molecules from two antiviral libraries (Life Chemicals [LC] and ASINEX) against RdRP. Here, we report six antiviral molecules (F3407-4105, F6523-2250, F6559-0746 from LC and BDG 33693278, BDG 33693315, LAS 34156196 from ASINEX), which show substantial interactions with key amino acid residues of the active site of SARS-CoV-2 RdRP and exhibit higher binding affinity (>7.5 kcalmol-1) than Galidesivir, an Food and Drug Administration-approved inhibitor of the same. Further, molecular dynamics simulation and Molecular Mechanics Poisson-Boltzmann Surface Area results confirmed that identified molecules with RdRP formed higher stable RdRP-inhibitor(s) complex than RdRP-Galidesvir complex. Our findings suggest that these molecules could be potential inhibitors of SARS-CoV-2 RdRP. However, further in vitro and preclinical experiments would be required to validate these potential inhibitors of SARS-CoV-2 protein.


Subject(s)
Antiviral Agents/pharmacology , COVID-19/drug therapy , Computational Chemistry/methods , Coronavirus RNA-Dependent RNA Polymerase/antagonists & inhibitors , Drug Discovery/methods , Drug Evaluation, Preclinical/methods , Pandemics , SARS-CoV-2/drug effects , Amino Acid Motifs , Amino Acid Sequence , Antiviral Agents/chemistry , Antiviral Agents/pharmacokinetics , Catalytic Domain/drug effects , Coronavirus RNA-Dependent RNA Polymerase/chemistry , Databases, Chemical , Molecular Docking Simulation , Molecular Dynamics Simulation , Molecular Structure , Protein Binding , Protein Conformation , SARS-CoV-2/enzymology , Sequence Alignment , Sequence Homology, Amino Acid , Small Molecule Libraries
5.
Infect Genet Evol ; 97: 105153, 2022 01.
Article in English | MEDLINE | ID: covidwho-1521407

ABSTRACT

Amid the ongoing COVID-19 pandemic, it has become increasingly important to monitor the mutations that arise in the SARS-CoV-2 virus, to prepare public health strategies and guide the further development of vaccines and therapeutics. The spike (S) protein and the proteins comprising the RNA-Dependent RNA Polymerase (RdRP) are key vaccine and drug targets, respectively, making mutation surveillance of these proteins of great importance. Full protein sequences were downloaded from the GISAID database, aligned, and the variants identified. 437,006 unique viral genomes were analyzed. Polymorphisms in the protein sequence were investigated and examined longitudinally to identify sequence and strain variants appearing between January 5th, 2020 and January 16th, 2021. A structural analysis was also performed to investigate mutations in the receptor binding domain and the N-terminal domain of the spike protein. Within the spike protein, there were 766 unique mutations observed in the N-terminal domain and 360 in the receptor binding domain. Four residues that directly contact ACE2 were mutated in more than 100 sequences, including positions K417, Y453, S494, and N501. Within the furin cleavage site of the spike protein, a high degree of conservation was observed, but the P681H mutation was observed in 10.47% of sequences analyzed. Within the RNA dependent RNA polymerase complex proteins, 327 unique mutations were observed in Nsp8, 166 unique mutations were observed in Nsp7, and 1157 unique mutations were observed in Nsp12. Only 4 sequences analyzed contained mutations in the 9 residues that directly interact with the therapeutic Remdesivir, suggesting limited mutations in drug interacting residues. The identification of new variants emphasizes the need for further study on the effects of the mutations and the implications of increased prevalence, particularly for vaccine or therapeutic efficacy.


Subject(s)
COVID-19/epidemiology , Coronavirus RNA-Dependent RNA Polymerase/chemistry , Genome, Viral , Mutation , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/chemistry , Viral Nonstructural Proteins/chemistry , Adenosine Monophosphate/analogs & derivatives , Adenosine Monophosphate/chemistry , Adenosine Monophosphate/pharmacology , Africa/epidemiology , Alanine/analogs & derivatives , Alanine/chemistry , Alanine/pharmacology , Amino Acid Substitution , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Asia/epidemiology , Binding Sites , COVID-19/drug therapy , COVID-19/virology , Coronavirus RNA-Dependent RNA Polymerase/genetics , Coronavirus RNA-Dependent RNA Polymerase/metabolism , Databases, Factual , Epidemiological Monitoring , Europe/epidemiology , Evolution, Molecular , Furin/genetics , Furin/metabolism , Gene Expression , Humans , Molecular Docking Simulation , Protein Binding , Protein Conformation, alpha-Helical , Protein Conformation, beta-Strand , Protein Interaction Domains and Motifs , SARS-CoV-2/classification , SARS-CoV-2/pathogenicity , Spike Glycoprotein, Coronavirus/antagonists & inhibitors , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism , United States/epidemiology , Viral Nonstructural Proteins/genetics , Viral Nonstructural Proteins/metabolism
6.
Biologicals ; 75: 29-36, 2022 Jan.
Article in English | MEDLINE | ID: covidwho-1517058

ABSTRACT

The RNA dependent RNA polymerase (RdRp) plays crucial role in virus life cycle by replicating the viral genome. The SARS-CoV-2 is an RNA virus that rapidly spread worldwide and acquired mutations. This study was carried out to identify mutations in RdRp as the SARS-CoV-2 spread in India. We compared 50217 RdRp sequences reported from India with the first reported RdRp sequence from Wuhan, China to identify 223 mutations acquired among Indian isolates. Our protein modelling study revealed that several mutants can potentially alter stability and flexibility of RdRp. We predicted the potential B cell epitopes contributed by RdRp and identified thirty-six linear continuous and twenty-five discontinuous epitopes. Among 223 RdRp mutants, 44% of them localises in the B cell epitopes region. Altogether, this study highlights the need to identify and characterize the variations in RdRp to understand the impact of these mutations on SARS-CoV-2.


Subject(s)
COVID-19/immunology , Coronavirus RNA-Dependent RNA Polymerase/genetics , Coronavirus RNA-Dependent RNA Polymerase/immunology , Epitopes, B-Lymphocyte/chemistry , Epitopes, B-Lymphocyte/immunology , Mutation , SARS-CoV-2/enzymology , COVID-19/virology , Coronavirus RNA-Dependent RNA Polymerase/chemistry , Enzyme Stability/genetics , Humans , India , SARS-CoV-2/genetics , SARS-CoV-2/immunology
7.
Sci Rep ; 11(1): 18851, 2021 09 22.
Article in English | MEDLINE | ID: covidwho-1434149

ABSTRACT

In this pandemic SARS-CoV-2 crisis, any attempt to contain and eliminate the virus will also stop its spread and consequently decrease the risk of severe illness and death. While ozone treatment has been suggested as an effective disinfection process, no precise mechanism of action has been previously reported. This study aimed to further investigate the effect of ozone treatment on SARS-CoV-2. Therefore, virus collected from nasopharyngeal and oropharyngeal swab and sputum samples from symptomatic patients was exposed to ozone for different exposure times. The virus morphology and structure were monitored and analyzed through Atomic Force Microscopy (AFM), Transmission Electron Microscopy (TEM), Atomic Absorption Spectroscopy (AAS), and ATR-FTIR. The obtained results showed that ozone treatment not only unsettles the virus morphology but also alters the virus proteins' structure and conformation through amino acid disturbance and Zn ion release from the virus non-structural proteins. These results could provide a clearer pathway for virus elimination and therapeutics preparation.


Subject(s)
COVID-19/drug therapy , Ozone/pharmacology , SARS-CoV-2/chemistry , SARS-CoV-2/drug effects , Coronavirus Papain-Like Proteases/chemistry , Coronavirus Papain-Like Proteases/metabolism , Coronavirus RNA-Dependent RNA Polymerase/chemistry , Coronavirus RNA-Dependent RNA Polymerase/metabolism , Humans , Microscopy, Electron, Transmission , Protein Structure, Secondary/drug effects , Protein Structure, Tertiary/drug effects , SARS-CoV-2/ultrastructure , Time Factors , Viral Envelope/chemistry , Viral Envelope/drug effects , Viral Regulatory and Accessory Proteins/chemistry , Viral Regulatory and Accessory Proteins/metabolism , Zinc/chemistry , Zinc/metabolism
8.
PLoS Comput Biol ; 17(9): e1009384, 2021 09.
Article in English | MEDLINE | ID: covidwho-1405333

ABSTRACT

Apart from the canonical fingers, palm and thumb domains, the RNA dependent RNA polymerases (RdRp) from the viral order Nidovirales possess two additional domains. Of these, the function of the Nidovirus RdRp associated nucleotidyl transferase domain (NiRAN) remains unanswered. The elucidation of the 3D structure of RdRp from the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), provided the first ever insights into the domain organisation and possible functional characteristics of the NiRAN domain. Using in silico tools, we predict that the NiRAN domain assumes a kinase or phosphotransferase like fold and binds nucleoside triphosphates at its proposed active site. Additionally, using molecular docking we have predicted the binding of three widely used kinase inhibitors and five well characterized anti-microbial compounds at the NiRAN domain active site along with their drug-likeliness. For the first time ever, using basic biochemical tools, this study shows the presence of a kinase like activity exhibited by the SARS-CoV-2 RdRp. Interestingly, a well-known kinase inhibitor- Sorafenib showed a significant inhibition and dampened viral load in SARS-CoV-2 infected cells. In line with the current global COVID-19 pandemic urgency and the emergence of newer strains with significantly higher infectivity, this study provides a new anti-SARS-CoV-2 drug target and potential lead compounds for drug repurposing against SARS-CoV-2.


Subject(s)
Antiviral Agents/pharmacology , Coronavirus RNA-Dependent RNA Polymerase/antagonists & inhibitors , Protein Domains , SARS-CoV-2/drug effects , Catalytic Domain , Computer Simulation , Coronavirus RNA-Dependent RNA Polymerase/chemistry , Coronavirus RNA-Dependent RNA Polymerase/metabolism , Humans
9.
Mol Med ; 27(1): 105, 2021 09 09.
Article in English | MEDLINE | ID: covidwho-1403209

ABSTRACT

BACKGROUND: Vaccination programs have been launched worldwide to halt the spread of COVID-19. However, the identification of existing, safe compounds with combined treatment and prophylactic properties would be beneficial to individuals who are waiting to be vaccinated, particularly in less economically developed countries, where vaccine availability may be initially limited. METHODS: We used a data-driven approach, combining results from the screening of a large transcriptomic database (L1000) and molecular docking analyses, with in vitro tests using a lung organoid model of SARS-CoV-2 entry, to identify drugs with putative multimodal properties against COVID-19. RESULTS: Out of thousands of FDA-approved drugs considered, we observed that atorvastatin was the most promising candidate, as its effects negatively correlated with the transcriptional changes associated with infection. Atorvastatin was further predicted to bind to SARS-CoV-2's main protease and RNA-dependent RNA polymerase, and was shown to inhibit viral entry in our lung organoid model. CONCLUSIONS: Small clinical studies reported that general statin use, and specifically, atorvastatin use, are associated with protective effects against COVID-19. Our study corroborrates these findings and supports the investigation of atorvastatin in larger clinical studies. Ultimately, our framework demonstrates one promising way to fast-track the identification of compounds for COVID-19, which could similarly be applied when tackling future pandemics.


Subject(s)
Antiviral Agents/pharmacology , Atorvastatin/pharmacology , COVID-19/drug therapy , Lung/drug effects , Organoids/drug effects , SARS-CoV-2/drug effects , Antiviral Agents/chemistry , Atorvastatin/chemistry , COVID-19/prevention & control , Cell Line , Coronavirus 3C Proteases/chemistry , Coronavirus RNA-Dependent RNA Polymerase/chemistry , Doxycycline/pharmacology , Drug Approval , Drug Repositioning , Gene Expression Regulation/drug effects , Humans , Lung/virology , Models, Biological , Molecular Docking Simulation , Organoids/virology , Raloxifene Hydrochloride/chemistry , Raloxifene Hydrochloride/pharmacology , SARS-CoV-2/physiology , Spike Glycoprotein, Coronavirus/genetics , Trifluoperazine/chemistry , Trifluoperazine/pharmacology , United States , United States Food and Drug Administration , Vesiculovirus/genetics , Virus Internalization/drug effects
10.
Int J Mol Sci ; 22(6)2021 Mar 15.
Article in English | MEDLINE | ID: covidwho-1389394

ABSTRACT

SARS-CoV-2 currently lacks effective first-line drug treatment. We present promising data from in silico docking studies of new Methisazone compounds (modified with calcium, Ca; iron, Fe; magnesium, Mg; manganese, Mn; or zinc, Zn) designed to bind more strongly to key proteins involved in replication of SARS-CoV-2. In this in silico molecular docking study, we investigated the inhibiting role of Methisazone and the modified drugs against SARS-CoV-2 proteins: ribonucleic acid (RNA)-dependent RNA polymerase (RdRp), spike protein, papain-like protease (PlPr), and main protease (MPro). We found that the highest binding interactions were found with the spike protein (6VYB), with the highest overall binding being observed with Mn-bound Methisazone at -8.3 kcal/mol, followed by Zn and Ca at -8.0 kcal/mol, and Fe and Mg at -7.9 kcal/mol. We also found that the metal-modified Methisazone had higher affinity for PlPr and MPro. In addition, we identified multiple binding pockets that could be singly or multiply occupied on all proteins tested. The best binding energy was with Mn-Methisazone versus spike protein, and the largest cumulative increases in binding energies were found with PlPr. We suggest that further studies are warranted to identify whether these compounds may be effective for treatment and/or prophylaxis.


Subject(s)
Antiviral Agents/chemistry , Metals/chemistry , Methisazone/chemistry , Molecular Docking Simulation , SARS-CoV-2/chemistry , Antiviral Agents/metabolism , COVID-19/drug therapy , Calcium/chemistry , Calcium/metabolism , Coronavirus 3C Proteases/chemistry , Coronavirus 3C Proteases/metabolism , Coronavirus Papain-Like Proteases/chemistry , Coronavirus Papain-Like Proteases/metabolism , Coronavirus RNA-Dependent RNA Polymerase/chemistry , Coronavirus RNA-Dependent RNA Polymerase/metabolism , Drug Design , Humans , Iron/chemistry , Iron/metabolism , Magnesium/chemistry , Magnesium/metabolism , Manganese/chemistry , Manganese/metabolism , Metals/metabolism , Methisazone/metabolism , Models, Molecular , Molecular Dynamics Simulation , Protein Binding , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/metabolism , Zinc/chemistry , Zinc/metabolism
11.
Cell ; 184(1): 184-193.e10, 2021 01 07.
Article in English | MEDLINE | ID: covidwho-1385213

ABSTRACT

Transcription of SARS-CoV-2 mRNA requires sequential reactions facilitated by the replication and transcription complex (RTC). Here, we present a structural snapshot of SARS-CoV-2 RTC as it transitions toward cap structure synthesis. We determine the atomic cryo-EM structure of an extended RTC assembled by nsp7-nsp82-nsp12-nsp132-RNA and a single RNA-binding protein, nsp9. Nsp9 binds tightly to nsp12 (RdRp) NiRAN, allowing nsp9 N terminus inserting into the catalytic center of nsp12 NiRAN, which then inhibits activity. We also show that nsp12 NiRAN possesses guanylyltransferase activity, catalyzing the formation of cap core structure (GpppA). The orientation of nsp13 that anchors the 5' extension of template RNA shows a remarkable conformational shift, resulting in zinc finger 3 of its ZBD inserting into a minor groove of paired template-primer RNA. These results reason an intermediate state of RTC toward mRNA synthesis, pave a way to understand the RTC architecture, and provide a target for antiviral development.


Subject(s)
Coronavirus RNA-Dependent RNA Polymerase/chemistry , Cryoelectron Microscopy , RNA, Messenger/chemistry , RNA, Viral/chemistry , SARS-CoV-2/chemistry , Viral Replicase Complex Proteins/chemistry , Amino Acid Sequence , Coronavirus/chemistry , Coronavirus/classification , Coronavirus/enzymology , Coronavirus RNA-Dependent RNA Polymerase/metabolism , Methyltransferases/metabolism , Models, Molecular , RNA Helicases/metabolism , RNA-Binding Proteins/chemistry , RNA-Binding Proteins/metabolism , SARS-CoV-2/enzymology , Sequence Alignment , Transcription, Genetic , Viral Nonstructural Proteins/chemistry , Viral Nonstructural Proteins/metabolism , Virus Replication
12.
Molecules ; 26(13)2021 Jun 28.
Article in English | MEDLINE | ID: covidwho-1383893

ABSTRACT

The work is devoted to the study of the complementarity of the electronic structures of the ligands and SARS-CoV-2 RNA-dependent RNA polymerase. The research methodology was based on determining of 3D maps of electron densities of complexes using an original quantum free-orbital AlteQ approach. We observed a positive relationship between the parameters of the electronic structure of the enzyme and ligands. A complementarity factor of the enzyme-ligand complexes has been proposed. The console applications of the AlteQ complementarity assessment for Windows and Linux (alteq_map_enzyme_ligand_4_win.exe and alteq_map_enzyme_ligand_4_linux) are available for free at the ChemoSophia webpage.


Subject(s)
Coronavirus RNA-Dependent RNA Polymerase/chemistry , Electrons , SARS-CoV-2/enzymology , Algorithms , Amides/chemistry , Antiviral Agents/chemistry , Ligands , Molecular Structure , Protein Binding , Pyrazines/chemistry , Ribonucleosides/chemistry
13.
Cell Rep ; 36(9): 109650, 2021 08 31.
Article in English | MEDLINE | ID: covidwho-1363915

ABSTRACT

Coronaviruses have evolved elaborate multisubunit machines to replicate and transcribe their genomes. Central to these machines are the RNA-dependent RNA polymerase subunit (nsp12) and its intimately associated cofactors (nsp7 and nsp8). We use a high-throughput magnetic-tweezers approach to develop a mechanochemical description of this core polymerase. The core polymerase exists in at least three catalytically distinct conformations, one being kinetically consistent with incorporation of incorrect nucleotides. We provide evidence that the RNA-dependent RNA polymerase (RdRp) uses a thermal ratchet instead of a power stroke to transition from the pre- to post-translocated state. Ultra-stable magnetic tweezers enable the direct observation of coronavirus polymerase deep and long-lived backtracking that is strongly stimulated by secondary structures in the template. The framework we present here elucidates one of the most important structure-dynamics-function relationships in human health today and will form the grounds for understanding the regulation of this complex.


Subject(s)
COVID-19/virology , Coronavirus RNA-Dependent RNA Polymerase/physiology , Nucleotides/metabolism , RNA, Viral/biosynthesis , SARS-CoV-2/physiology , Coronavirus RNA-Dependent RNA Polymerase/chemistry , High-Throughput Screening Assays , Humans , Models, Molecular , Molecular Conformation , Nucleotides/chemistry , RNA, Viral/chemistry , Single Molecule Imaging , Viral Nonstructural Proteins/chemistry , Viral Nonstructural Proteins/physiology
14.
FEBS Lett ; 595(17): 2248-2256, 2021 09.
Article in English | MEDLINE | ID: covidwho-1326724

ABSTRACT

The endoplasmic reticulum transmembrane protein vesicle-associated membrane protein-associated protein (VAP) plays a central role in the formation and function of membrane contact sites (MCS) through its interactions with proteins. The major sperm protein (MSP) domain of VAP binds to a variety of sequences which are referred to as FFAT-like motifs. In this study, we investigated the interactions of eight peptides containing FFAT-like motifs with the VAP-A MSP domain (VAP-AMSP ) by solution NMR. Six of eight peptides are specifically bound to VAP-A. Furthermore, we found that the RNA-dependent RNA polymerase of severe acute respiratory syndrome coronavirus 2 has an FFAT-like motif which specifically binds to VAP-AMSP as well as other FFAT-like motifs. Our results will contribute to the discovery of new VAP interactors.


Subject(s)
Coronavirus RNA-Dependent RNA Polymerase/chemistry , Peptides/chemistry , SARS-CoV-2/enzymology , Vesicular Transport Proteins/chemistry , Amino Acid Motifs , Coronavirus RNA-Dependent RNA Polymerase/metabolism , Humans , Nuclear Magnetic Resonance, Biomolecular , Peptides/metabolism , Protein Binding , SARS-CoV-2/metabolism , Vesicular Transport Proteins/metabolism
15.
Biochem Biophys Res Commun ; 571: 26-31, 2021 09 24.
Article in English | MEDLINE | ID: covidwho-1312941

ABSTRACT

The pandemic of SARS-CoV-2 has necessitated expedited research efforts towards finding potential antiviral targets and drug development measures. While new drug discovery is time consuming, drug repurposing has been a promising area for elaborate virtual screening and identification of existing FDA approved drugs that could possibly be used for targeting against functions of various proteins of SARS-CoV-2 virus. RNA dependent RNA polymerase (RdRp) is an important enzyme for the virus that mediates replication of the viral RNA. Inhibition of RdRp could inhibit viral RNA replication and thus new virus particle production. Here, we screened non-nucleoside antivirals and found three out of them to be strongest in binding to RdRp out of which two retained binding even using molecular dynamic simulations. We propose these two drugs as potential RdRp inhibitors which need further in-depth testing.


Subject(s)
Antiviral Agents/pharmacology , COVID-19/drug therapy , Coronavirus RNA-Dependent RNA Polymerase/antagonists & inhibitors , SARS-CoV-2/drug effects , SARS-CoV-2/enzymology , Amides/pharmacology , Antiviral Agents/chemistry , Benzimidazoles/pharmacology , COVID-19/virology , Carbamates/pharmacology , Catalytic Domain , Computer Simulation , Coronavirus RNA-Dependent RNA Polymerase/chemistry , Cyclopropanes/pharmacology , Drug Evaluation, Preclinical , Drug Repositioning , Fluorenes/pharmacology , Humans , Lactams, Macrocyclic/pharmacology , Molecular Docking Simulation , Molecular Dynamics Simulation , Pandemics , Proline/analogs & derivatives , Proline/pharmacology , Protein Conformation , Quinoxalines/pharmacology , Sulfonamides/pharmacology
16.
Sci Signal ; 14(690)2021 07 06.
Article in English | MEDLINE | ID: covidwho-1299215

ABSTRACT

Inorganic polyphosphates (polyPs) are linear polymers composed of repeated phosphate (PO4 3-) units linked together by multiple high-energy phosphoanhydride bonds. In addition to being a source of energy, polyPs have cytoprotective and antiviral activities. Here, we investigated the antiviral activities of long-chain polyPs against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In molecular docking analyses, polyPs interacted with several conserved amino acid residues in angiotensin-converting enzyme 2 (ACE2), the host receptor that facilitates virus entry, and in viral RNA-dependent RNA polymerase (RdRp). ELISA and limited proteolysis assays using nano- LC-MS/MS mapped polyP120 binding to ACE2, and site-directed mutagenesis confirmed interactions between ACE2 and SARS-CoV-2 RdRp and identified the specific amino acid residues involved. PolyP120 enhanced the proteasomal degradation of both ACE2 and RdRp, thus impairing replication of the British B.1.1.7 SARS-CoV-2 variant. We thus tested polyPs for functional interactions with the virus in SARS-CoV-2-infected Vero E6 and Caco2 cells and in primary human nasal epithelial cells. Delivery of a nebulized form of polyP120 reduced the amounts of viral positive-sense genomic and subgenomic RNAs, of RNA transcripts encoding proinflammatory cytokines, and of viral structural proteins, thereby presenting SARS-CoV-2 infection in cells in vitro.


Subject(s)
Antiviral Agents/pharmacology , COVID-19/drug therapy , Polyphosphates/pharmacology , SARS-CoV-2/drug effects , Administration, Inhalation , Amino Acid Sequence , Angiotensin-Converting Enzyme 2/chemistry , Angiotensin-Converting Enzyme 2/metabolism , Animals , Antiviral Agents/administration & dosage , Antiviral Agents/chemistry , COVID-19/metabolism , COVID-19/virology , Caco-2 Cells , Chlorocebus aethiops , Coronavirus RNA-Dependent RNA Polymerase/chemistry , Coronavirus RNA-Dependent RNA Polymerase/genetics , Coronavirus RNA-Dependent RNA Polymerase/metabolism , Cytokines/metabolism , HEK293 Cells , Host Microbial Interactions/drug effects , Host Microbial Interactions/genetics , Host Microbial Interactions/physiology , Humans , In Vitro Techniques , Models, Biological , Molecular Docking Simulation , Nebulizers and Vaporizers , Polyphosphates/administration & dosage , Polyphosphates/chemistry , Proteasome Endopeptidase Complex/metabolism , Protein Interaction Domains and Motifs , Proteolysis/drug effects , RNA, Viral/genetics , RNA, Viral/metabolism , SARS-CoV-2/genetics , SARS-CoV-2/physiology , Sequence Homology, Amino Acid , Signal Transduction/drug effects , Vero Cells , Virus Replication/drug effects
17.
Sci Rep ; 11(1): 13705, 2021 07 01.
Article in English | MEDLINE | ID: covidwho-1294480

ABSTRACT

The D614G mutation in the Spike protein of the SARS-CoV-2 has effectively replaced the early pandemic-causing variant. Using pseudotyped lentivectors, we confirmed that the aspartate replacement by glycine in position 614 is markedly more infectious. Molecular modelling suggests that the G614 mutation facilitates transition towards an open state of the Spike protein. To explain the epidemiological success of D614G, we analysed the evolution of 27,086 high-quality SARS-CoV-2 genome sequences from GISAID. We observed striking coevolution of D614G with the P323L mutation in the viral polymerase. Importantly, the exclusive presence of G614 or L323 did not become epidemiologically relevant. In contrast, the combination of the two mutations gave rise to a viral G/L variant that has all but replaced the initial D/P variant. Our results suggest that the P323L mutation, located in the interface domain of the RNA-dependent RNA polymerase, is a necessary alteration that led to the epidemiological success of the present variant of SARS-CoV-2. However, we did not observe a significant correlation between reported COVID-19 mortality in different countries and the prevalence of the Wuhan versus G/L variant. Nevertheless, when comparing the speed of emergence and the ultimate predominance in individual countries, it is clear that the G/L variant displays major epidemiological supremacy over the original variant.


Subject(s)
COVID-19/virology , Coronavirus RNA-Dependent RNA Polymerase/genetics , Point Mutation , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics , COVID-19/epidemiology , Coronavirus RNA-Dependent RNA Polymerase/chemistry , Humans , Models, Molecular , Protein Conformation , SARS-CoV-2/chemistry , Spike Glycoprotein, Coronavirus/chemistry
18.
Pharmacol Rep ; 73(6): 1754-1764, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1283833

ABSTRACT

BACKGROUND: SARS-CoV-2 is a newly emerged human coronavirus that severely affected human health and the economy. The viral RNA-dependent RNA polymerase (RdRp) is a crucial protein target to stop virus replication. The adenosine derivative, remdesivir, was authorized for emergency use 10 months ago by the United States FDA against COVID-19 despite its doubtful efficacy against SARS-CoV-2. METHODS: A dozen modifications based on remdesivir are tested against SARS-CoV-2 RdRp using combined molecular docking and dynamics simulation in this work. RESULTS: The results reveal a better binding affinity of 11 modifications compared to remdesivir. Compounds 8, 9, 10, and 11 show the best binding affinities against SARS-CoV-2 RdRp conformations gathered during 100 ns of the Molecular Dynamics Simulation (MDS) run (- 8.13 ± 0.45 kcal/mol, - 8.09 ± 0.67 kcal/mol, - 8.09 ± 0.64 kcal/mol, and - 8.07 ± 0.73 kcal/mol, respectively). CONCLUSIONS: The present study suggests these four compounds as potential SARS-CoV-2 RdRp inhibitors, which need to be validated experimentally.


Subject(s)
Adenosine Monophosphate/analogs & derivatives , Adenosine/analogs & derivatives , Alanine/analogs & derivatives , Antiviral Agents/chemistry , Coronavirus RNA-Dependent RNA Polymerase/antagonists & inhibitors , Drug Design , Adenosine Monophosphate/chemistry , Alanine/chemistry , Binding Sites , COVID-19 , Computer Simulation , Coronavirus RNA-Dependent RNA Polymerase/chemistry , Humans , Molecular Docking Simulation , Molecular Dynamics Simulation , Molecular Structure , SARS-CoV-2/pathogenicity
19.
J Am Soc Mass Spectrom ; 32(7): 1618-1630, 2021 Jul 07.
Article in English | MEDLINE | ID: covidwho-1267989

ABSTRACT

Coronavirus (CoV) nonstructural proteins (nsps) assemble to form the replication-transcription complex (RTC) responsible for viral RNA synthesis. nsp7 and nsp8 are important cofactors of the RTC, as they interact and regulate the activity of RNA-dependent RNA polymerase and other nsps. To date, no structure of the full-length SARS-CoV-2 nsp7:nsp8 complex has been published. The current understanding of this complex is based on structures from truncated constructs, with missing electron densities, or from related CoV species where SARS-CoV-2 nsp7 and nsp8 share upward of 90% sequence identity. Despite available structures solved using crystallography and cryo-EM representing detailed static snapshots of the nsp7:nsp8 complex, it is evident that the complex has a high degree of structural plasticity. However, relatively little is known about the conformational dynamics of the individual proteins and how they complex to interact with other nsps. Here, the solution-based structural proteomic techniques, hydrogen-deuterium exchange mass spectrometry (HDX-MS) and cross-linking mass spectrometry (XL-MS), illuminate the dynamics of SARS-CoV-2 full-length nsp7 and nsp8 proteins and the nsp7:nsp8 protein complex. Results presented from the two techniques are complementary and validate the interaction surfaces identified from the published three-dimensional heterotetrameric crystal structure of the SARS-CoV-2 truncated nsp7:nsp8 complex. Furthermore, mapping of XL-MS data onto higher-order complexes suggests that SARS-CoV-2 nsp7 and nsp8 do not assemble into a hexadecameric structure as implied by the SARS-CoV full-length nsp7:nsp8 crystal structure. Instead, our results suggest that the nsp7:nsp8 heterotetramer can dissociate into a stable dimeric unit that might bind to nsp12 in the RTC without significantly altering nsp7-nsp8 interactions.


Subject(s)
Coronavirus RNA-Dependent RNA Polymerase/chemistry , Proteomics/methods , Viral Nonstructural Proteins/chemistry , COVID-19/virology , Coronavirus RNA-Dependent RNA Polymerase/genetics , Coronavirus RNA-Dependent RNA Polymerase/metabolism , Humans , Hydrogen Deuterium Exchange-Mass Spectrometry , Models, Molecular , Protein Conformation , SARS-CoV-2/chemistry , Viral Nonstructural Proteins/genetics , Viral Nonstructural Proteins/metabolism
20.
Science ; 373(6551): 236-241, 2021 07 09.
Article in English | MEDLINE | ID: covidwho-1266364

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causal agent of COVID-19, uses an RNA-dependent RNA polymerase (RdRp) for the replication of its genome and the transcription of its genes. We found that the catalytic subunit of the RdRp, nsp12, ligates two iron-sulfur metal cofactors in sites that were modeled as zinc centers in the available cryo-electron microscopy structures of the RdRp complex. These metal binding sites are essential for replication and for interaction with the viral helicase. Oxidation of the clusters by the stable nitroxide TEMPOL caused their disassembly, potently inhibited the RdRp, and blocked SARS-CoV-2 replication in cell culture. These iron-sulfur clusters thus serve as cofactors for the SARS-CoV-2 RdRp and are targets for therapy of COVID-19.


Subject(s)
Coenzymes/metabolism , Coronavirus RNA-Dependent RNA Polymerase/antagonists & inhibitors , Coronavirus RNA-Dependent RNA Polymerase/chemistry , Cyclic N-Oxides/pharmacology , Iron/metabolism , SARS-CoV-2/drug effects , Sulfur/metabolism , Amino Acid Motifs , Animals , Antiviral Agents/pharmacology , Binding Sites , Catalytic Domain , Chlorocebus aethiops , Coenzymes/chemistry , Coronavirus RNA-Dependent RNA Polymerase/metabolism , Enzyme Inhibitors/pharmacology , Iron/chemistry , Protein Domains , RNA Helicases/metabolism , SARS-CoV-2/enzymology , SARS-CoV-2/physiology , Spin Labels , Sulfur/chemistry , Vero Cells , Viral Nonstructural Proteins/metabolism , Virus Replication/drug effects , Zinc/metabolism
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