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1.
J Med Chem ; 65(1): 876-884, 2022 01 13.
Article in English | MEDLINE | ID: covidwho-1606194

ABSTRACT

Coronavirus disease 2019 (COVID-19) pandemic, a global health threat, was caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The SARS-CoV-2 papain-like cysteine protease (PLpro) was recognized as a promising drug target because of multiple functions in virus maturation and antiviral immune responses. Inhibitor GRL0617 occupied the interferon-stimulated gene 15 (ISG15) C-terminus-binding pocket and showed an effective antiviral inhibition. Here, we described a novel peptide-drug conjugate (PDC), in which GRL0617 was linked to a sulfonium-tethered peptide derived from PLpro-specific substrate LRGG. The EM-C and EC-M PDCs showed a promising in vitro IC50 of 7.40 ± 0.37 and 8.63 ± 0.55 µM, respectively. EC-M could covalently label PLpro active site C111 and display anti-ISGylation activities in cellular assays. The results represent the first attempt to design PDCs composed of stabilized peptide inhibitors and GRL0617 to inhibit PLpro. These novel PDCs provide promising opportunities for antiviral drug design.


Subject(s)
Aniline Compounds/chemistry , Antiviral Agents/metabolism , Benzamides/chemistry , Coronavirus Papain-Like Proteases/metabolism , Drug Design , Naphthalenes/chemistry , Peptides/chemistry , SARS-CoV-2/enzymology , Aniline Compounds/metabolism , Aniline Compounds/pharmacology , Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , Benzamides/metabolism , Benzamides/pharmacology , COVID-19/drug therapy , COVID-19/pathology , COVID-19/virology , Cell Line , Cell Survival/drug effects , Coronavirus Papain-Like Proteases/chemistry , Cytokines/chemistry , Drug Evaluation, Preclinical , Humans , Inhibitory Concentration 50 , Naphthalenes/metabolism , Naphthalenes/pharmacology , SARS-CoV-2/isolation & purification , Ubiquitins/chemistry
2.
J Am Soc Mass Spectrom ; 33(1): 181-188, 2022 Jan 05.
Article in English | MEDLINE | ID: covidwho-1596214

ABSTRACT

Affinity selection-mass spectrometry, which includes magnetic microbead affinity selection-screening (MagMASS), is ideal for the discovery of ligands in complex mixtures that bind to pharmacological targets. Therapeutic agents are needed to prevent or treat COVID-19, which is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Infection of human cells by SARS-CoV-2 involves binding of the virus spike protein subunit 1 (S1) to the human cell receptor angiotensin converting enzyme-2 (ACE2). Like antibodies, small molecules have the potential to block the interaction of the viral S1 protein with human ACE2 and prevent SARS-CoV-2 infection. Therefore, a MagMASS assay was developed for the discovery of ligands to the S1 protein. Unlike previous MagMASS approaches, this new assay used robotics for 5-fold enhancement of throughput and sensitivity. The assay was validated using the SBP-1 peptide, which is identical to the ACE2 amino acid sequence recognized by the S1 protein, and then applied to the discovery of natural ligands from botanical extracts. Small molecule ligands to the S1 protein were discovered in extracts of the licorice species, Glycyrrhiza inflata. In particular, the licorice ligand licochalcone A was identified through dereplication and comparison with standards using HPLC with high-resolution tandem mass spectrometry.


Subject(s)
Antiviral Agents/pharmacology , COVID-19/drug therapy , Drug Discovery/methods , SARS-CoV-2/drug effects , Spike Glycoprotein, Coronavirus/metabolism , Angiotensin-Converting Enzyme 2/metabolism , Antiviral Agents/chemistry , Binding Sites/drug effects , COVID-19/metabolism , Chalcones/chemistry , Chalcones/pharmacology , Drug Evaluation, Preclinical/methods , Fabaceae/chemistry , Humans , Ligands , Mass Spectrometry/methods , Molecular Docking Simulation , Protein Binding/drug effects , SARS-CoV-2/metabolism
3.
Int J Mol Sci ; 22(24)2021 Dec 18.
Article in English | MEDLINE | ID: covidwho-1580690

ABSTRACT

Since the start of the COVID-19 outbreak, pharmaceutical companies and research groups have focused on the development of vaccines and antiviral drugs against SARS-CoV-2. Here, we apply a drug repurposing strategy to identify drug candidates that are able to block the entrance of the virus into human cells. By combining virtual screening with in vitro pseudovirus assays and antiviral assays in Human Lung Tissue (HLT) cells, we identify entrectinib as a potential antiviral drug.


Subject(s)
Benzamides/pharmacology , COVID-19/drug therapy , Indazoles/pharmacology , SARS-CoV-2/drug effects , Animals , Antiviral Agents/pharmacology , Benzamides/metabolism , COVID-19/metabolism , Cell Line , Chlorocebus aethiops , Drug Evaluation, Preclinical , Drug Repositioning/methods , Humans , Indazoles/metabolism , Lung/pathology , Lung/virology , Molecular Docking Simulation , SARS-CoV-2/metabolism , SARS-CoV-2/pathogenicity , Vero Cells , Virus Attachment/drug effects
4.
Molecules ; 27(1)2021 Dec 30.
Article in English | MEDLINE | ID: covidwho-1580564

ABSTRACT

The COVID-19 pandemic has caused millions of fatalities since 2019. Despite the availability of vaccines for this disease, new strains are causing rapid ailment and are a continuous threat to vaccine efficacy. Here, molecular docking and simulations identify strong inhibitors of the allosteric site of the SARS-CoV-2 virus RNA dependent RNA polymerase (RdRp). More than one hundred different flavonoids were docked with the SARS-CoV-2 RdRp allosteric site through computational screening. The three top hits were Naringoside, Myricetin and Aureusidin 4,6-diglucoside. Simulation analyses confirmed that they are in constant contact during the simulation time course and have strong association with the enzyme's allosteric site. Absorption, distribution, metabolism, excretion and toxicity (ADMET) data provided medicinal information of these top three hits. They had good human intestinal absorption (HIA) concentrations and were non-toxic. Due to high mutation rates in the active sites of the viral enzyme, these new allosteric site inhibitors offer opportunities to drug SARS-CoV-2 RdRp. These results provide new information for the design of novel allosteric inhibitors against SARS-CoV-2 RdRp.


Subject(s)
Antiviral Agents/pharmacology , COVID-19/drug therapy , Computational Biology/methods , Coronavirus RNA-Dependent RNA Polymerase/antagonists & inhibitors , Drug Evaluation, Preclinical , Flavonoids/pharmacology , SARS-CoV-2/enzymology , Allosteric Site , COVID-19/virology , Catalytic Domain , Drug Design , Humans , Intestinal Absorption , Molecular Docking Simulation
5.
Molecules ; 26(24)2021 Dec 09.
Article in English | MEDLINE | ID: covidwho-1572566

ABSTRACT

This study demonstrates the inhibitory effect of 42 pyrimidonic pharmaceuticals (PPs) on the 3-chymotrypsin-like protease of SARS-CoV-2 (3CLpro) through molecular docking, molecular dynamics simulations, and free binding energies by means of molecular mechanics-Poisson Boltzmann surface area (MM-PBSA) and molecular mechanics-generalized Born surface area (MM-GBSA). Of these tested PPs, 11 drugs approved by the US Food and Drug Administration showed an excellent binding affinity to the catalytic residues of 3CLpro of His41 and Cys145: uracil mustard, cytarabine, floxuridine, trifluridine, stavudine, lamivudine, zalcitabine, telbivudine, tipiracil, citicoline, and uridine triacetate. Their percentage of residues involved in binding at the active sites ranged from 56 to 100, and their binding affinities were in the range from -4.6 ± 0.14 to -7.0 ± 0.19 kcal/mol. The molecular dynamics as determined by a 200 ns simulation run of solvated docked complexes confirmed the stability of PP conformations that bound to the catalytic dyad and the active sites of 3CLpro. The free energy of binding also demonstrates the stability of the PP-3CLpro complexes. Citicoline and uridine triacetate showed free binding energies of -25.53 and -7.07 kcal/mol, respectively. Therefore, I recommend that they be repurposed for the fight against COVID-19, following proper experimental and clinical validation.


Subject(s)
COVID-19/drug therapy , Coronavirus 3C Proteases/antagonists & inhibitors , Coronavirus Papain-Like Proteases/antagonists & inhibitors , Drug Repositioning/methods , Protease Inhibitors/pharmacology , SARS-CoV-2/drug effects , Acetates/chemistry , Acetates/pharmacology , Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Cytidine Diphosphate Choline/chemistry , Cytidine Diphosphate Choline/pharmacology , Drug Evaluation, Preclinical , Humans , Molecular Docking Simulation , Molecular Dynamics Simulation , Protease Inhibitors/chemistry , Uridine/analogs & derivatives , Uridine/chemistry , Uridine/pharmacology
6.
Pharmacol Res ; 172: 105820, 2021 10.
Article in English | MEDLINE | ID: covidwho-1531713

ABSTRACT

Coronavirus Disease 2019 (COVID-19) is caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), which enter the host cells through the interaction between its receptor binding domain (RBD) of spike glycoprotein with angiotensin-converting enzyme 2 (ACE2) receptor on the plasma membrane of host cell. Neutralizing antibodies and peptide binders of RBD can block viral infection, however, the concern of accessibility and affordability of viral infection inhibitors has been raised. Here, we report the identification of natural compounds as potential SARS-CoV-2 entry inhibitors using the molecular docking-based virtual screening coupled with bilayer interferometry (BLI). From a library of 1871 natural compounds, epigallocatechin gallate (EGCG), 20(R)-ginsenoside Rg3 (RRg3), 20(S)-ginsenoside Rg3 (SRg3), isobavachalcone (Ibvc), isochlorogenic A (IscA) and bakuchiol (Bkc) effectively inhibited pseudovirus entry at concentrations up to 100 µM. Among these compounds, four compounds, EGCG, Ibvc, salvianolic acid A (SalA), and isoliensinine (Isl), were effective in inhibiting SARS-CoV-2-induced cytopathic effect and plaque formation in Vero E6 cells. The EGCG was further validated with no observable animal toxicity and certain antiviral effect against SARS-CoV-2 pseudovirus mutants (D614G, N501Y, N439K & Y453F). Interestingly, EGCG, Bkc and Ibvc bind to ACE2 receptor in BLI assay, suggesting a dual binding to RBD and ACE2. Current findings shed some insight into identifications and validations of SARS-CoV-2 entry inhibitors from natural compounds.


Subject(s)
Angiotensin-Converting Enzyme 2/antagonists & inhibitors , Antiviral Agents/chemistry , Biological Products/chemistry , COVID-19/drug therapy , Enzyme Inhibitors/chemistry , SARS-CoV-2/enzymology , Spike Glycoprotein, Coronavirus/metabolism , Animals , Antiviral Agents/pharmacology , Binding, Competitive , Biological Products/pharmacology , Catechin/analogs & derivatives , Catechin/pharmacology , Cell Membrane/metabolism , Cell Membrane/ultrastructure , Chalcones/pharmacology , Chlorogenic Acid/analogs & derivatives , Chlorogenic Acid/pharmacology , Dose-Response Relationship, Drug , Drug Evaluation, Preclinical , Enzyme Inhibitors/pharmacology , Ginsenosides/pharmacology , Humans , Interferometry , Mice, Inbred C57BL , Molecular Dynamics Simulation , Phenols/pharmacology , Protein Binding
7.
mBio ; 12(2)2021 03 30.
Article in English | MEDLINE | ID: covidwho-1522913

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a recently emerged virus that causes coronavirus infectious disease 2019 (COVID-19). SARS-CoV-2 spike protein, like SARS-CoV-1, uses the angiotensin converting enzyme 2 (ACE2) as a cellular receptor to initiate infection. Compounds that interfere with the SARS-CoV-2 spike protein receptor binding domain protein (RBD)-ACE2 receptor interaction may function as entry inhibitors. Here, we used a dual strategy of molecular docking and surface plasmon resonance (SPR) screening of compound libraries to identify those that bind to human ACE2 or the SARS-CoV-2 spike protein receptor binding domain (RBD). Molecular modeling screening interrogated 57,641 compounds and focused on the region of ACE2 that is engaged by RBD of the SARS-CoV-2 spike glycoprotein and vice versa. SPR screening used immobilized human ACE2 and SARS-CoV-2 Spike protein to evaluate the binding of these proteins to a library of 3,141 compounds. These combined screens identified compounds from these libraries that bind at KD (equilibrium dissociation constant) <3 µM affinity to their respective targets, 17 for ACE2 and 6 for SARS-CoV-2 RBD. Twelve ACE2 binders and six of the RBD binders compete with the RBD-ACE2 interaction in an SPR-based competition assay. These compounds included registered drugs and dyes used in biomedical applications. A Vero-E6 cell-based SARS-CoV-2 infection assay was used to evaluate infection blockade by candidate entry inhibitors. Three compounds demonstrated dose-dependent antiviral in vitro potency-Evans blue, sodium lifitegrast, and lumacaftor. This study has identified potential drugs for repurposing as SARS-CoV-2 entry inhibitors or as chemical scaffolds for drug development.IMPORTANCE SARS-CoV-2, the causative agent of COVID-19, has caused more than 60 million cases worldwide with almost 1.5 million deaths as of November 2020. Repurposing existing drugs is the most rapid path to clinical intervention for emerging diseases. Using an in silico screen of 57,641 compounds and a biophysical screen of 3,141 compounds, we identified 22 compounds that bound to either the angiotensin converting enzyme 2 (ACE2) and/or the SARS-CoV-2 spike protein receptor binding domain (SARS-CoV-2 spike protein RBD). Nine of these drugs were identified by both screening methods. Three of the identified compounds, Evans blue, sodium lifitegrast, and lumacaftor, were found to inhibit viral replication in a Vero-E6 cell-based SARS-CoV-2 infection assay and may have utility as repurposed therapeutics. All 22 identified compounds provide scaffolds for the development of new chemical entities for the treatment of COVID-19.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , Antiviral Agents/pharmacology , COVID-19/drug therapy , Spike Glycoprotein, Coronavirus/metabolism , Virus Attachment/drug effects , Virus Replication/drug effects , Aminopyridines/pharmacology , Animals , Benzodioxoles/pharmacology , Cell Line , Chlorocebus aethiops , Drug Evaluation, Preclinical , Drug Repositioning , Evans Blue/pharmacology , Humans , Molecular Docking Simulation , Phenylalanine/analogs & derivatives , Phenylalanine/pharmacology , Protein Binding/drug effects , SARS-CoV-2/drug effects , SARS-CoV-2/physiology , Sulfones/pharmacology , Surface Plasmon Resonance , Vero Cells
8.
Int J Mol Sci ; 22(21)2021 Oct 28.
Article in English | MEDLINE | ID: covidwho-1518611

ABSTRACT

Inhaled nebulized interferon (IFN)-α and IFN-ß have been shown to be effective in the management of coronavirus disease 2019 (COVID-19). We aimed to construct a virus-free rapid detection system for high-throughput screening of IFN-like compounds that induce viral RNA degradation and suppress the replication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We prepared a SARS-CoV-2 subreplicon RNA expression vector which contained the SARS-CoV-2 5'-UTR, the partial sequence of ORF1a, luciferase, nucleocapsid, ORF10, and 3'-UTR under the control of the cytomegalovirus promoter. The expression vector was transfected into Calu-3 cells and treated with IFN-α and the IFNAR2 agonist CDM-3008 (RO8191) for 3 days. SARS-CoV-2 subreplicon RNA degradation was subsequently evaluated based on luciferase levels. IFN-α and CDM-3008 suppressed SARS-CoV-2 subreplicon RNA in a dose-dependent manner, with IC50 values of 193 IU/mL and 2.54 µM, respectively. HeLa cells stably expressing SARS-CoV-2 subreplicon RNA were prepared and treated with the IFN-α and pan-JAK inhibitor Pyridone 6 or siRNA-targeting ISG20. IFN-α activity was canceled with Pyridone 6. The knockdown of ISG20 partially canceled IFN-α activity. Collectively, we constructed a virus-free rapid detection system to measure SARS-CoV-2 RNA suppression. Our data suggest that the SARS-CoV-2 subreplicon RNA was degraded by IFN-α-induced ISG20 exonuclease activity.


Subject(s)
Antiviral Agents/pharmacology , Drug Evaluation, Preclinical/methods , Interferon-alpha/pharmacology , RNA, Viral/metabolism , SARS-CoV-2/genetics , Cell Line, Tumor , Dose-Response Relationship, Drug , Exoribonucleases/genetics , Genetic Vectors , HeLa Cells , Humans , Interferon-alpha/administration & dosage , Luciferases/genetics , Luciferases/metabolism , Naphthyridines/administration & dosage , Naphthyridines/pharmacology , Oxadiazoles/administration & dosage , Oxadiazoles/pharmacology , RNA, Viral/drug effects , Replicon
9.
Biosci Rep ; 41(10)2021 10 29.
Article in English | MEDLINE | ID: covidwho-1510636

ABSTRACT

Coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus has become a global health emergency. Although new vaccines have been generated and being implicated, discovery and application of novel preventive and control measures are warranted. We aimed to identify compounds that may possess the potential to either block the entry of virus to host cells or attenuate its replication upon infection. Using host cell surface receptor expression (angiotensin-converting enzyme 2 (ACE2) and Transmembrane protease serine 2 (TMPRSS2)) analysis as an assay, we earlier screened several synthetic and natural compounds and identified candidates that showed ability to down-regulate their expression. Here, we report experimental and computational analyses of two small molecules, Mortaparib and MortaparibPlus that were initially identified as dual novel inhibitors of mortalin and PARP-1, for their activity against SARS-CoV-2. In silico analyses showed that MortaparibPlus, but not Mortaparib, stably binds into the catalytic pocket of TMPRSS2. In vitro analysis of control and treated cells revealed that MortaparibPlus caused down-regulation of ACE2 and TMPRSS2; Mortaparib did not show any effect. Furthermore, computational analysis on SARS-CoV-2 main protease (Mpro) that also predicted the inhibitory activity of MortaparibPlus. However, cell-based antiviral drug screening assay showed 30-60% viral inhibition in cells treated with non-toxic doses of either MortaparibPlus or Mortaparib. The data suggest that these two closely related compounds possess multimodal anti-COVID-19 activities. Whereas MortaparibPlus works through direct interactions/effects on the host cell surface receptors (ACE2 and TMPRSS2) and the virus protein (Mpro), Mortaparib involves independent mechanisms, elucidation of which warrants further studies.


Subject(s)
Antiviral Agents/pharmacology , COVID-19/drug therapy , Computational Biology/methods , Angiotensin-Converting Enzyme 2/immunology , Angiotensin-Converting Enzyme 2/metabolism , Antiviral Agents/immunology , COVID-19/immunology , Cell Line, Tumor , Drug Evaluation, Preclinical/methods , HSP70 Heat-Shock Proteins/antagonists & inhibitors , Humans , Mitochondrial Proteins/antagonists & inhibitors , Poly (ADP-Ribose) Polymerase-1/antagonists & inhibitors , SARS-CoV-2/immunology , Serine Endopeptidases/immunology , Serine Endopeptidases/metabolism , Spike Glycoprotein, Coronavirus/metabolism , Virus Internalization/drug effects
10.
Nat Commun ; 12(1): 6343, 2021 11 03.
Article in English | MEDLINE | ID: covidwho-1500461

ABSTRACT

Peptide secondary metabolites are common in nature and have diverse pharmacologically-relevant functions, from antibiotics to cross-kingdom signaling. Here, we present a method to design large libraries of modified peptides in Escherichia coli and screen them in vivo to identify those that bind to a single target-of-interest. Constrained peptide scaffolds were produced using modified enzymes gleaned from microbial RiPP (ribosomally synthesized and post-translationally modified peptide) pathways and diversified to build large libraries. The binding of a RiPP to a protein target leads to the intein-catalyzed release of an RNA polymerase σ factor, which drives the expression of selectable markers. As a proof-of-concept, a selection was performed for binding to the SARS-CoV-2 Spike receptor binding domain. A 1625 Da constrained peptide (AMK-1057) was found that binds with similar affinity (990 ± 5 nM) as an ACE2-derived peptide. This demonstrates a generalizable method to identify constrained peptides that adhere to a single protein target, as a step towards "molecular glues" for therapeutics and diagnostics.


Subject(s)
Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Peptides/chemistry , Peptides/pharmacology , SARS-CoV-2/drug effects , COVID-19/drug therapy , COVID-19/virology , Drug Design , Drug Evaluation, Preclinical , Humans , Kinetics , Models, Molecular , Peptides/genetics , Protein Binding , SARS-CoV-2/genetics , SARS-CoV-2/physiology , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism
12.
J Mol Model ; 27(11): 341, 2021 Nov 03.
Article in English | MEDLINE | ID: covidwho-1499466

ABSTRACT

From the beginning of pandemic, more than 240 million people have been infected with a death rate higher than 2%. Indeed, the current exit strategy involving the spreading of vaccines must be combined with progress in effective treatment development. This scenario is sadly supported by the vaccine's immune activation time and the inequalities in the global immunization schedule. Bringing the crises under control means providing the world population with accessible and impactful new therapeutics. We screened a natural product library that contains a unique collection of 2370 natural products into the binding site of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) main protease (Mpro). According to the docking score and to the interaction at the active site, three phenylethanoid glycosides (forsythiaside A, isoacteoside, and verbascoside) were selected. In order to provide better insight into the atomistic interaction and test the impact of the three selected compounds at the binding site, we resorted to a half microsecond-long molecular dynamics simulation. As a result, we are showing that forsythiaside A is the most stable molecule and it is likely to possess the highest inhibitory effect against SARS-CoV-2 Mpro. Phenylethanoid glycosides also have been reported to have both protease and kinase activity. This kinase inhibitory activity is very beneficial in fighting viruses inside the body as kinases are required for viral entry, metabolism, and/or reproduction. The dual activity (kinase/protease) of phenylethanoid glycosides makes them very promising anit-COVID-19 agents.


Subject(s)
Antiviral Agents/pharmacology , Coronavirus 3C Proteases/antagonists & inhibitors , Coronavirus Protease Inhibitors/pharmacology , Glycosides/pharmacology , Antiviral Agents/chemistry , Binding Sites , Coronavirus 3C Proteases/chemistry , Coronavirus 3C Proteases/metabolism , Coronavirus Protease Inhibitors/chemistry , Drug Evaluation, Preclinical , Glucosides/chemistry , Glucosides/metabolism , Glucosides/pharmacology , Glycosides/chemistry , Glycosides/metabolism , Hydrogen Bonding , Molecular Docking Simulation , Molecular Dynamics Simulation , Phenols/chemistry , Phenols/metabolism , Phenols/pharmacology
13.
Angew Chem Int Ed Engl ; 60(48): 25428-25435, 2021 11 22.
Article in English | MEDLINE | ID: covidwho-1490696

ABSTRACT

The main protease (3CLp) of the SARS-CoV-2, the causative agent for the COVID-19 pandemic, is one of the main targets for drug development. To be active, 3CLp relies on a complex interplay between dimerization, active site flexibility, and allosteric regulation. The deciphering of these mechanisms is a crucial step to enable the search for inhibitors. In this context, using NMR spectroscopy, we studied the conformation of dimeric 3CLp from the SARS-CoV-2 and monitored ligand binding, based on NMR signal assignments. We performed a fragment-based screening that led to the identification of 38 fragment hits. Their binding sites showed three hotspots on 3CLp, two in the substrate binding pocket and one at the dimer interface. F01 is a non-covalent inhibitor of the 3CLp and has antiviral activity in SARS-CoV-2 infected cells. This study sheds light on the complex structure-function relationships of 3CLp and constitutes a strong basis to assist in developing potent 3CLp inhibitors.


Subject(s)
Antiviral Agents/pharmacology , Coronavirus 3C Proteases/antagonists & inhibitors , Cysteine Proteinase Inhibitors/pharmacology , SARS-CoV-2/drug effects , Small Molecule Libraries/pharmacology , Animals , Antiviral Agents/chemistry , Binding Sites , Chlorocebus aethiops , Coronavirus 3C Proteases/chemistry , Cysteine Proteinase Inhibitors/chemistry , Drug Evaluation, Preclinical , Microbial Sensitivity Tests , Nuclear Magnetic Resonance, Biomolecular , Protein Conformation , Protein Multimerization , SARS-CoV-2/chemistry , Small Molecule Libraries/chemistry , Vero Cells
14.
Molecules ; 26(21)2021 Oct 30.
Article in English | MEDLINE | ID: covidwho-1488678

ABSTRACT

Papain-like protease is an essential enzyme in the proteolytic processing required for the replication of SARS-CoV-2. Accordingly, such an enzyme is an important target for the development of anti-SARS-CoV-2 agents which may reduce the mortality associated with outbreaks of SARS-CoV-2. A set of 69 semi-synthesized molecules that exhibited the structural features of SARS-CoV-2 papain-like protease inhibitors (PLPI) were docked against the coronavirus papain-like protease (PLpro) enzyme (PDB ID: (4OW0). Docking studies showed that derivatives 34 and 58 were better than the co-crystallized ligand while derivatives 17, 28, 31, 40, 41, 43, 47, 54, and 65 exhibited good binding modes and binding free energies. The pharmacokinetic profiling study was conducted according to the four principles of the Lipinski rules and excluded derivative 31. Furthermore, ADMET and toxicity studies showed that derivatives 28, 34, and 47 have the potential to be drugs and have been demonstrated as safe when assessed via seven toxicity models. Finally, comparing the molecular orbital energies and the molecular electrostatic potential maps of 28, 34, and 47 against the co-crystallized ligand in a DFT study indicated that 28 is the most promising candidate to interact with the target receptor (PLpro).


Subject(s)
Coronavirus Papain-Like Proteases/metabolism , SARS-CoV-2/drug effects , Virus Replication/drug effects , Antiviral Agents/pharmacology , COVID-19/drug therapy , COVID-19/metabolism , Computer Simulation , Coronavirus Papain-Like Proteases/drug effects , Drug Evaluation, Preclinical/methods , Humans , Ligands , Molecular Docking Simulation , Molecular Dynamics Simulation , Papain/metabolism , Peptide Hydrolases/metabolism , Protease Inhibitors/chemistry , Protease Inhibitors/metabolism , Protease Inhibitors/pharmacology , SARS-CoV-2/metabolism , SARS-CoV-2/pathogenicity
15.
Int J Mol Sci ; 22(21)2021 Oct 28.
Article in English | MEDLINE | ID: covidwho-1488612

ABSTRACT

Inhaled nebulized interferon (IFN)-α and IFN-ß have been shown to be effective in the management of coronavirus disease 2019 (COVID-19). We aimed to construct a virus-free rapid detection system for high-throughput screening of IFN-like compounds that induce viral RNA degradation and suppress the replication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We prepared a SARS-CoV-2 subreplicon RNA expression vector which contained the SARS-CoV-2 5'-UTR, the partial sequence of ORF1a, luciferase, nucleocapsid, ORF10, and 3'-UTR under the control of the cytomegalovirus promoter. The expression vector was transfected into Calu-3 cells and treated with IFN-α and the IFNAR2 agonist CDM-3008 (RO8191) for 3 days. SARS-CoV-2 subreplicon RNA degradation was subsequently evaluated based on luciferase levels. IFN-α and CDM-3008 suppressed SARS-CoV-2 subreplicon RNA in a dose-dependent manner, with IC50 values of 193 IU/mL and 2.54 µM, respectively. HeLa cells stably expressing SARS-CoV-2 subreplicon RNA were prepared and treated with the IFN-α and pan-JAK inhibitor Pyridone 6 or siRNA-targeting ISG20. IFN-α activity was canceled with Pyridone 6. The knockdown of ISG20 partially canceled IFN-α activity. Collectively, we constructed a virus-free rapid detection system to measure SARS-CoV-2 RNA suppression. Our data suggest that the SARS-CoV-2 subreplicon RNA was degraded by IFN-α-induced ISG20 exonuclease activity.


Subject(s)
Antiviral Agents/pharmacology , Drug Evaluation, Preclinical/methods , Interferon-alpha/pharmacology , RNA, Viral/metabolism , SARS-CoV-2/genetics , Cell Line, Tumor , Dose-Response Relationship, Drug , Exoribonucleases/genetics , Genetic Vectors , HeLa Cells , Humans , Interferon-alpha/administration & dosage , Luciferases/genetics , Luciferases/metabolism , Naphthyridines/administration & dosage , Naphthyridines/pharmacology , Oxadiazoles/administration & dosage , Oxadiazoles/pharmacology , RNA, Viral/drug effects , Replicon
16.
Nat Commun ; 12(1): 6097, 2021 10 20.
Article in English | MEDLINE | ID: covidwho-1475295

ABSTRACT

Effective treatments against Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) are urgently needed. Monoclonal antibodies have shown promising results in patients. Here, we evaluate the in vivo prophylactic and therapeutic effect of COVA1-18, a neutralizing antibody highly potent against the B.1.1.7 isolate. In both prophylactic and therapeutic settings, SARS-CoV-2 remains undetectable in the lungs of treated hACE2 mice. Therapeutic treatment also causes a reduction in viral loads in the lungs of Syrian hamsters. When administered at 10 mg kg-1 one day prior to a high dose SARS-CoV-2 challenge in cynomolgus macaques, COVA1-18 shows very strong antiviral activity in the upper respiratory compartments. Using a mathematical model, we estimate that COVA1-18 reduces viral infectivity by more than 95% in these compartments, preventing lymphopenia and extensive lung lesions. Our findings demonstrate that COVA1-18 has a strong antiviral activity in three preclinical models and could be a valuable candidate for further clinical evaluation.


Subject(s)
Antibodies, Monoclonal/administration & dosage , Antibodies, Neutralizing/administration & dosage , Antiviral Agents/administration & dosage , COVID-19/drug therapy , SARS-CoV-2/immunology , Angiotensin-Converting Enzyme 2/genetics , Animals , Antibodies, Monoclonal/pharmacokinetics , Antiviral Agents/pharmacokinetics , COVID-19/blood , COVID-19/immunology , COVID-19/virology , Disease Models, Animal , Drug Evaluation, Preclinical , Female , Humans , Lung/metabolism , Lung/virology , Macaca fascicularis , Male , Mesocricetus , Mice , Mice, Transgenic , SARS-CoV-2/isolation & purification , Tissue Distribution , Viral Load
17.
Sci Rep ; 11(1): 20295, 2021 10 13.
Article in English | MEDLINE | ID: covidwho-1467129

ABSTRACT

Novel SARS-CoV-2, an etiological factor of Coronavirus disease 2019 (COVID-19), poses a great challenge to the public health care system. Among other druggable targets of SARS-Cov-2, the main protease (Mpro) is regarded as a prominent enzyme target for drug developments owing to its crucial role in virus replication and transcription. We pursued a computational investigation to identify Mpro inhibitors from a compiled library of natural compounds with proven antiviral activities using a hierarchical workflow of molecular docking, ADMET assessment, dynamic simulations and binding free-energy calculations. Five natural compounds, Withanosides V and VI, Racemosides A and B, and Shatavarin IX, obtained better binding affinity and attained stable interactions with Mpro key pocket residues. These intermolecular key interactions were also retained profoundly in the simulation trajectory of 100 ns time scale indicating tight receptor binding. Free energy calculations prioritized Withanosides V and VI as the top candidates that can act as effective SARS-CoV-2 Mpro inhibitors.


Subject(s)
COVID-19/drug therapy , Coronavirus 3C Proteases/metabolism , Phytochemicals/pharmacology , Antiviral Agents/pharmacology , Computational Biology/methods , Coronavirus 3C Proteases/drug effects , Coronavirus 3C Proteases/ultrastructure , Drug Evaluation, Preclinical/methods , Humans , Molecular Docking Simulation/methods , Molecular Dynamics Simulation , Peptide Hydrolases/drug effects , Phytochemicals/metabolism , Protease Inhibitors/pharmacology , Protein Binding/drug effects , SARS-CoV-2/drug effects , SARS-CoV-2/pathogenicity
18.
PLoS One ; 16(10): e0258368, 2021.
Article in English | MEDLINE | ID: covidwho-1468173

ABSTRACT

Effective treatment of respiratory infections continues to be a major challenge. In high doses (≥160 ppm), inhaled Nitric Oxide (iNO) has been shown to act as a broad-spectrum antimicrobial agent, including its efficacy in vitro for coronavirus family. However, the safety of prolonged in vivo implementation of high-dose iNO therapy has not been studied. Herein we aim to explore the feasibility and safety of delivering continuous high-dose iNO over an extended period of time using an in vivo animal model. Yorkshire pigs were randomized to one of the following two groups: group 1, standard ventilation; and group 2, standard ventilation + continuous iNO 160 ppm + methylene blue (MB) as intravenous bolus, whenever required, to maintain metHb <6%. Both groups were ventilated continuously for 6 hours, then the animals were weaned from sedation, mechanical ventilation and followed for 3 days. During treatment, and on the third post-operative day, physiologic assessments were performed to monitor lung function and other significative markers were assessed for potential pulmonary or systemic injury. No significant change in lung function, or inflammatory markers were observed during the study period. Both gas exchange function, lung tissue cytokine analysis and histology were similar between treated and control animals. During treatment, levels of metHb were maintained <6% by administration of MB, and NO2 remained <5 ppm. Additionally, considering extrapulmonary effects, no significant changes were observed in biochemistry markers. Our findings showed that high-dose iNO delivered continuously over 6 hours with adjuvant MB is clinically feasible and safe. These findings support the development of investigations of continuous high-dose iNO treatment of respiratory tract infections, including SARS-CoV-2.


Subject(s)
Anti-Infective Agents/administration & dosage , Nitric Oxide/administration & dosage , Administration, Inhalation , Animals , Cytokines/analysis , Cytokines/blood , Drug Evaluation, Preclinical , Hemodynamics , Hemoglobin A/analysis , Lung/metabolism , Lung/pathology , Male , Methemoglobin/analysis , Methylene Blue/administration & dosage , Models, Animal , Nitrates/analysis , Nitrites/analysis , Swine
19.
Viruses ; 13(10)2021 10 08.
Article in English | MEDLINE | ID: covidwho-1463841

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected almost 200 million people worldwide and led to approximately 4 million deaths as of August 2021. Despite successful vaccine development, treatment options are limited. A promising strategy to specifically target viral infections is to suppress viral replication through RNA interference (RNAi). Hence, we designed eight small interfering RNAs (siRNAs) targeting the highly conserved 5'-untranslated region (5'-UTR) of SARS-CoV-2. The most promising candidate identified in initial reporter assays, termed siCoV6, targets the leader sequence of the virus, which is present in the genomic as well as in all subgenomic RNAs. In assays with infectious SARS-CoV-2, it reduced replication by two orders of magnitude and prevented the development of a cytopathic effect. Moreover, it retained its activity against the SARS-CoV-2 alpha variant and has perfect homology against all sequences of the delta variant that were analyzed by bioinformatic means. Interestingly, the siRNA was even highly active in virus replication assays with the SARS-CoV-1 family member. This work thus identified a very potent siRNA with a broad activity against various SARS-CoV viruses that represents a promising candidate for the development of new treatment options.


Subject(s)
Antiviral Agents/pharmacology , COVID-19/therapy , RNA Interference , RNA, Small Interfering/pharmacology , SARS-CoV-2/growth & development , Virus Replication/drug effects , 5' Untranslated Regions/genetics , Animals , Cell Line, Tumor , Chlorocebus aethiops , Drug Evaluation, Preclinical , HeLa Cells , Humans , RNA, Small Interfering/genetics , SARS-CoV-2/genetics , Vero Cells , Virus Replication/genetics
20.
Antiviral Res ; 195: 105183, 2021 11.
Article in English | MEDLINE | ID: covidwho-1458592

ABSTRACT

The likelihood of continued circulation of COVID-19 and its variants, and novel coronaviruses due to future zoonotic transmissions, combined with the current paucity of coronavirus antivirals, emphasize the need for improved screening in developing effective antivirals for the treatment of infection by SARS-CoV-2 (CoV2) and other coronaviruses. Here we report the development of a live-cell based assay for evaluating the intracellular function of the critical, highly-conserved CoV2 target, the Main 3C-like protease (Mpro). This assay is based on expression of native wild-type mature CoV2 Mpro, the function of which is quantitatively evaluated in living cells through cleavage of a biosensor leading to loss of fluorescence. Evaluation does not require cell harvesting, allowing for multiple measurements from the same cells facilitating quantification of Mpro inhibition, as well as recovery of function upon removal of inhibitory drugs. The pan-coronavirus Mpro inhibitor, GC376, was utilized in this assay and effective inhibition of intracellular CoV2 Mpro was found to be consistent with levels required to inhibit CoV2 infection of human lung cells. We demonstrate that GC376 is an effective inhibitor of intracellular CoV2 Mpro at low micromolar levels, while other predicted Mpro inhibitors, bepridil and alverine, are not. Results indicate this system can provide a highly effective high-throughput coronavirus Mpro screening system.


Subject(s)
Biosensing Techniques , Coronavirus 3C Proteases/antagonists & inhibitors , Protease Inhibitors/pharmacology , Pyrrolidines/pharmacology , SARS-CoV-2/enzymology , Sulfonic Acids/pharmacology , Drug Evaluation, Preclinical , Fluorescence , HEK293 Cells , Humans
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