Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 63
Filter
1.
Proc Natl Acad Sci U S A ; 118(43)2021 10 26.
Article in English | MEDLINE | ID: covidwho-1493345

ABSTRACT

The host cell serine protease TMPRSS2 is an attractive therapeutic target for COVID-19 drug discovery. This protease activates the Spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and of other coronaviruses and is essential for viral spread in the lung. Utilizing rational structure-based drug design (SBDD) coupled to substrate specificity screening of TMPRSS2, we have discovered covalent small-molecule ketobenzothiazole (kbt) TMPRSS2 inhibitors which are structurally distinct from and have significantly improved activity over the existing known inhibitors Camostat and Nafamostat. Lead compound MM3122 (4) has an IC50 (half-maximal inhibitory concentration) of 340 pM against recombinant full-length TMPRSS2 protein, an EC50 (half-maximal effective concentration) of 430 pM in blocking host cell entry into Calu-3 human lung epithelial cells of a newly developed VSV-SARS-CoV-2 chimeric virus, and an EC50 of 74 nM in inhibiting cytopathic effects induced by SARS-CoV-2 virus in Calu-3 cells. Further, MM3122 blocks Middle East respiratory syndrome coronavirus (MERS-CoV) cell entry with an EC50 of 870 pM. MM3122 has excellent metabolic stability, safety, and pharmacokinetics in mice, with a half-life of 8.6 h in plasma and 7.5 h in lung tissue, making it suitable for in vivo efficacy evaluation and a promising drug candidate for COVID-19 treatment.


Subject(s)
Benzothiazoles/pharmacology , COVID-19/drug therapy , Oligopeptides/pharmacology , SARS-CoV-2/drug effects , Serine Endopeptidases/genetics , Animals , Benzamidines/chemistry , Benzothiazoles/pharmacokinetics , COVID-19/genetics , COVID-19/virology , Cell Line , Drug Design , Epithelial Cells/drug effects , Epithelial Cells/virology , Esters/chemistry , Guanidines/chemistry , Humans , Lung/drug effects , Lung/virology , Mice , Middle East Respiratory Syndrome Coronavirus/drug effects , Middle East Respiratory Syndrome Coronavirus/pathogenicity , Oligopeptides/pharmacokinetics , SARS-CoV-2/pathogenicity , Serine Endopeptidases/drug effects , Serine Endopeptidases/ultrastructure , Small Molecule Libraries/pharmacology , Substrate Specificity/drug effects , Virus Internalization/drug effects
2.
Sci Rep ; 11(1): 16174, 2021 08 10.
Article in English | MEDLINE | ID: covidwho-1351974

ABSTRACT

Oncostatin M (OSM) is a pleiotropic, interleukin-6 family inflammatory cytokine that plays an important role in inflammatory diseases, including inflammatory bowel disease, rheumatoid arthritis, and cancer progression and metastasis. Recently, elevated OSM levels have been found in the serum of COVID-19 patients in intensive care units. Multiple anti-OSM therapeutics have been investigated, but to date no OSM small molecule inhibitors are clinically available. To pursue a high-throughput screening and structure-based drug discovery strategy to design a small molecule inhibitor of OSM, milligram quantities of highly pure, bioactive OSM are required. Here, we developed a reliable protocol to produce highly pure unlabeled and isotope enriched OSM from E. coli for biochemical and NMR studies. High yields (ca. 10 mg/L culture) were obtained in rich and minimal defined media cultures. Purified OSM was characterized by mass spectrometry and circular dichroism. The bioactivity was confirmed by induction of OSM/OSM receptor signaling through STAT3 phosphorylation in human breast cancer cells. Optimized buffer conditions yielded 1H, 15N HSQC NMR spectra with intense, well-dispersed peaks. Titration of 15N OSM with a small molecule inhibitor showed chemical shift perturbations for several key residues with a binding affinity of 12.2 ± 3.9 µM. These results demonstrate the value of bioactive recombinant human OSM for NMR-based small molecule screening.


Subject(s)
Drug Discovery/methods , Oncostatin M/antagonists & inhibitors , Small Molecule Libraries/pharmacology , Binding Sites , Cell Line, Tumor , Humans , Magnetic Resonance Spectroscopy/methods , Molecular Docking Simulation , Oncostatin M/chemistry , Oncostatin M/metabolism , Phosphorylation , Protein Binding , STAT3 Transcription Factor/metabolism , Small Molecule Libraries/chemistry
3.
Cell Chem Biol ; 28(5): 594-609, 2021 05 20.
Article in English | MEDLINE | ID: covidwho-1271598

ABSTRACT

Initial successes in developing small molecule ligands for non-coding RNAs have underscored their potential as therapeutic targets. More recently, these successes have been aided by advances in biophysical and structural techniques for identification and characterization of more complex RNA structures; these higher-level folds present protein-like binding pockets that offer opportunities to design small molecules that could achieve a degree of selectivity often hard to obtain at the primary and secondary structure level. More specifically, identification and small molecule targeting of RNA tertiary and quaternary structures have allowed researchers to probe several human diseases and have resulted in promising clinical candidates. In this review we highlight a selection of diverse and exciting successes and the experimental approaches that led to their discovery. These studies include examples of recent developments in RNA-centric assays and ligands that provide insight into the features responsible for the affinity and biological outcome of RNA-targeted chemical probes. This report highlights the potential and emerging opportunities to selectively target RNA tertiary and quaternary structures as a route to better understand and, ultimately, treat many diseases.


Subject(s)
RNA/drug effects , Small Molecule Libraries/pharmacology , Humans , Ligands , Nucleic Acid Conformation , RNA/chemistry , Small Molecule Libraries/chemistry
4.
Biochem J ; 478(13): 2405-2423, 2021 07 16.
Article in English | MEDLINE | ID: covidwho-1292181

ABSTRACT

The coronavirus disease 2019 (COVID-19) pandemic, which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a global public health challenge. While the efficacy of vaccines against emerging and future virus variants remains unclear, there is a need for therapeutics. Repurposing existing drugs represents a promising and potentially rapid opportunity to find novel antivirals against SARS-CoV-2. The virus encodes at least nine enzymatic activities that are potential drug targets. Here, we have expressed, purified and developed enzymatic assays for SARS-CoV-2 nsp13 helicase, a viral replication protein that is essential for the coronavirus life cycle. We screened a custom chemical library of over 5000 previously characterized pharmaceuticals for nsp13 inhibitors using a fluorescence resonance energy transfer-based high-throughput screening approach. From this, we have identified FPA-124 and several suramin-related compounds as novel inhibitors of nsp13 helicase activity in vitro. We describe the efficacy of these drugs using assays we developed to monitor SARS-CoV-2 growth in Vero E6 cells.


Subject(s)
Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Drug Evaluation, Preclinical , RNA Helicases/antagonists & inhibitors , SARS-CoV-2/enzymology , Small Molecule Libraries/pharmacology , Viral Nonstructural Proteins/antagonists & inhibitors , Animals , Chlorocebus aethiops , Enzyme Assays , Fluorescence Resonance Energy Transfer , High-Throughput Screening Assays , RNA Helicases/metabolism , Reproducibility of Results , SARS-CoV-2/drug effects , Small Molecule Libraries/chemistry , Suramin/pharmacology , Vero Cells , Viral Nonstructural Proteins/metabolism
5.
Biochem J ; 478(13): 2499-2515, 2021 07 16.
Article in English | MEDLINE | ID: covidwho-1291175

ABSTRACT

The coronavirus 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), spread around the world with unprecedented health and socio-economic effects for the global population. While different vaccines are now being made available, very few antiviral drugs have been approved. The main viral protease (nsp5) of SARS-CoV-2 provides an excellent target for antivirals, due to its essential and conserved function in the viral replication cycle. We have expressed, purified and developed assays for nsp5 protease activity. We screened the nsp5 protease against a custom chemical library of over 5000 characterised pharmaceuticals. We identified calpain inhibitor I and three different peptidyl fluoromethylketones (FMK) as inhibitors of nsp5 activity in vitro, with IC50 values in the low micromolar range. By altering the sequence of our peptidomimetic FMK inhibitors to better mimic the substrate sequence of nsp5, we generated an inhibitor with a subnanomolar IC50. Calpain inhibitor I inhibited viral infection in monkey-derived Vero E6 cells, with an EC50 in the low micromolar range. The most potent and commercially available peptidyl-FMK compound inhibited viral growth in Vero E6 cells to some extent, while our custom peptidyl FMK inhibitor offered a marked antiviral improvement.


Subject(s)
Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Coronavirus 3C Proteases/antagonists & inhibitors , Drug Evaluation, Preclinical , SARS-CoV-2/enzymology , Small Molecule Libraries/pharmacology , Amino Acid Chloromethyl Ketones/pharmacology , Animals , Azoles/pharmacology , Chlorocebus aethiops , Coronavirus 3C Proteases/genetics , Coronavirus 3C Proteases/isolation & purification , Coronavirus 3C Proteases/metabolism , Enzyme Assays , Fluorescence Resonance Energy Transfer , High-Throughput Screening Assays , Leupeptins/pharmacology , Organoselenium Compounds/pharmacology , Peptidomimetics , RNA-Binding Proteins/metabolism , Reproducibility of Results , SARS-CoV-2/drug effects , Small Molecule Libraries/chemistry , Vero Cells , Viral Nonstructural Proteins/metabolism
6.
Biochem J ; 478(13): 2517-2531, 2021 07 16.
Article in English | MEDLINE | ID: covidwho-1290988

ABSTRACT

The COVID-19 pandemic has emerged as the biggest life-threatening disease of this century. Whilst vaccination should provide a long-term solution, this is pitted against the constant threat of mutations in the virus rendering the current vaccines less effective. Consequently, small molecule antiviral agents would be extremely useful to complement the vaccination program. The causative agent of COVID-19 is a novel coronavirus, SARS-CoV-2, which encodes at least nine enzymatic activities that all have drug targeting potential. The papain-like protease (PLpro) contained in the nsp3 protein generates viral non-structural proteins from a polyprotein precursor, and cleaves ubiquitin and ISG protein conjugates. Here we describe the expression and purification of PLpro. We developed a protease assay that was used to screen a custom compound library from which we identified dihydrotanshinone I and Ro 08-2750 as compounds that inhibit PLpro in protease and isopeptidase assays and also inhibit viral replication in cell culture-based assays.


Subject(s)
Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Coronavirus Papain-Like Proteases/antagonists & inhibitors , Drug Evaluation, Preclinical , SARS-CoV-2/enzymology , Small Molecule Libraries/pharmacology , Adenosine Monophosphate/analogs & derivatives , Adenosine Monophosphate/pharmacology , Alanine/analogs & derivatives , Alanine/pharmacology , Aniline Compounds/pharmacology , Animals , Benzamides/pharmacology , Chlorocebus aethiops , Coronavirus Papain-Like Proteases/genetics , Coronavirus Papain-Like Proteases/isolation & purification , Coronavirus Papain-Like Proteases/metabolism , Drug Synergism , Enzyme Assays , Flavins/pharmacology , Fluorescence Resonance Energy Transfer , Furans/pharmacology , High-Throughput Screening Assays , Inhibitory Concentration 50 , Naphthalenes/pharmacology , Phenanthrenes/pharmacology , Quinones/pharmacology , Reproducibility of Results , SARS-CoV-2/drug effects , SARS-CoV-2/growth & development , Small Molecule Libraries/chemistry , Vero Cells , Virus Replication/drug effects
7.
Biochem J ; 478(13): 2533-2535, 2021 07 16.
Article in English | MEDLINE | ID: covidwho-1290318

ABSTRACT

In response to the COVID-19 pandemic, we began a project in March 2020 to identify small molecule inhibitors of SARS-CoV-2 enzymes from a library of chemical compounds containing many established pharmaceuticals. Our hope was that inhibitors we found might slow the replication of the SARS-CoV-2 virus in cells and ultimately be useful in the treatment of COVID-19. The seven accompanying manuscripts describe the results of these chemical screens. This overview summarises the main highlights from these screens and discusses the implications of our results and how our results might be exploited in future.


Subject(s)
Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Drug Evaluation, Preclinical , SARS-CoV-2/enzymology , Small Molecule Libraries/pharmacology , Viral Nonstructural Proteins/antagonists & inhibitors , Animals , Enzyme Assays , Humans , SARS-CoV-2/drug effects , Small Molecule Libraries/chemistry , Viral Nonstructural Proteins/metabolism
8.
Biochem J ; 478(13): 2445-2464, 2021 07 16.
Article in English | MEDLINE | ID: covidwho-1290093

ABSTRACT

SARS-CoV-2 is a coronavirus that emerged in 2019 and rapidly spread across the world causing a deadly pandemic with tremendous social and economic costs. Healthcare systems worldwide are under great pressure, and there is an urgent need for effective antiviral treatments. The only currently approved antiviral treatment for COVID-19 is remdesivir, an inhibitor of viral genome replication. SARS-CoV-2 proliferation relies on the enzymatic activities of the non-structural proteins (nsp), which makes them interesting targets for the development of new antiviral treatments. With the aim to identify novel SARS-CoV-2 antivirals, we have purified the exoribonuclease/methyltransferase (nsp14) and its cofactor (nsp10) and developed biochemical assays compatible with high-throughput approaches to screen for exoribonuclease inhibitors. We have screened a library of over 5000 commercial compounds and identified patulin and aurintricarboxylic acid (ATA) as inhibitors of nsp14 exoribonuclease in vitro. We found that patulin and ATA inhibit replication of SARS-CoV-2 in a VERO E6 cell-culture model. These two new antiviral compounds will be valuable tools for further coronavirus research as well as potentially contributing to new therapeutic opportunities for COVID-19.


Subject(s)
Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Drug Evaluation, Preclinical , Exoribonucleases/antagonists & inhibitors , SARS-CoV-2/enzymology , Small Molecule Libraries/pharmacology , Viral Nonstructural Proteins/antagonists & inhibitors , Viral Regulatory and Accessory Proteins/antagonists & inhibitors , Animals , Aurintricarboxylic Acid/pharmacology , Chlorocebus aethiops , Enzyme Assays , Exoribonucleases/metabolism , Fluorescence , High-Throughput Screening Assays , Patulin/pharmacology , Reproducibility of Results , SARS-CoV-2/drug effects , Small Molecule Libraries/chemistry , Vero Cells , Viral Nonstructural Proteins/metabolism , Viral Regulatory and Accessory Proteins/metabolism
9.
Biochem J ; 478(13): 2465-2479, 2021 07 16.
Article in English | MEDLINE | ID: covidwho-1290092

ABSTRACT

SARS-CoV-2 is responsible for COVID-19, a human disease that has caused over 2 million deaths, stretched health systems to near-breaking point and endangered economies of countries and families around the world. Antiviral treatments to combat COVID-19 are currently lacking. Remdesivir, the only antiviral drug approved for the treatment of COVID-19, can affect disease severity, but better treatments are needed. SARS-CoV-2 encodes 16 non-structural proteins (nsp) that possess different enzymatic activities with important roles in viral genome replication, transcription and host immune evasion. One key aspect of host immune evasion is performed by the uridine-directed endoribonuclease activity of nsp15. Here we describe the expression and purification of nsp15 recombinant protein. We have developed biochemical assays to follow its activity, and we have found evidence for allosteric behaviour. We screened a custom chemical library of over 5000 compounds to identify nsp15 endoribonuclease inhibitors, and we identified and validated NSC95397 as an inhibitor of nsp15 endoribonuclease in vitro. Although NSC95397 did not inhibit SARS-CoV-2 growth in VERO E6 cells, further studies will be required to determine the effect of nsp15 inhibition on host immune evasion.


Subject(s)
Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Drug Evaluation, Preclinical , Endoribonucleases/antagonists & inhibitors , SARS-CoV-2/enzymology , Small Molecule Libraries/pharmacology , Viral Nonstructural Proteins/antagonists & inhibitors , Allosteric Regulation , Animals , Chlorocebus aethiops , Endoribonucleases/isolation & purification , Endoribonucleases/metabolism , Enzyme Assays , Fluorescence , High-Throughput Screening Assays , In Vitro Techniques , Kinetics , Naphthoquinones/pharmacology , Reproducibility of Results , SARS-CoV-2/drug effects , SARS-CoV-2/growth & development , Small Molecule Libraries/chemistry , Solutions , Vero Cells , Viral Nonstructural Proteins/isolation & purification , Viral Nonstructural Proteins/metabolism
10.
Biochem J ; 478(13): 2425-2443, 2021 07 16.
Article in English | MEDLINE | ID: covidwho-1289982

ABSTRACT

The coronavirus disease 2019 (COVID-19) global pandemic has turned into the largest public health and economic crisis in recent history impacting virtually all sectors of society. There is a need for effective therapeutics to battle the ongoing pandemic. Repurposing existing drugs with known pharmacological safety profiles is a fast and cost-effective approach to identify novel treatments. The COVID-19 etiologic agent is the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a single-stranded positive-sense RNA virus. Coronaviruses rely on the enzymatic activity of the replication-transcription complex (RTC) to multiply inside host cells. The RTC core catalytic component is the RNA-dependent RNA polymerase (RdRp) holoenzyme. The RdRp is one of the key druggable targets for CoVs due to its essential role in viral replication, high degree of sequence and structural conservation and the lack of homologues in human cells. Here, we have expressed, purified and biochemically characterised active SARS-CoV-2 RdRp complexes. We developed a novel fluorescence resonance energy transfer-based strand displacement assay for monitoring SARS-CoV-2 RdRp activity suitable for a high-throughput format. As part of a larger research project to identify inhibitors for all the enzymatic activities encoded by SARS-CoV-2, we used this assay to screen a custom chemical library of over 5000 approved and investigational compounds for novel SARS-CoV-2 RdRp inhibitors. We identified three novel compounds (GSK-650394, C646 and BH3I-1) and confirmed suramin and suramin-like compounds as in vitro SARS-CoV-2 RdRp activity inhibitors. We also characterised the antiviral efficacy of these drugs in cell-based assays that we developed to monitor SARS-CoV-2 growth.


Subject(s)
Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Coronavirus RNA-Dependent RNA Polymerase/antagonists & inhibitors , Drug Evaluation, Preclinical , SARS-CoV-2/enzymology , Small Molecule Libraries/pharmacology , Animals , Benzoates/pharmacology , Bridged Bicyclo Compounds, Heterocyclic/pharmacology , Chlorocebus aethiops , Coronavirus RNA-Dependent RNA Polymerase/metabolism , Enzyme Assays , Fluorescence Resonance Energy Transfer , High-Throughput Screening Assays , Holoenzymes/metabolism , Reproducibility of Results , SARS-CoV-2/drug effects , Small Molecule Libraries/chemistry , Suramin/pharmacology , Vero Cells , Viral Nonstructural Proteins/antagonists & inhibitors , Viral Nonstructural Proteins/metabolism
11.
Biochem J ; 478(13): 2481-2497, 2021 07 16.
Article in English | MEDLINE | ID: covidwho-1289949

ABSTRACT

The COVID-19 pandemic has presented itself as one of the most critical public health challenges of the century, with SARS-CoV-2 being the third member of the Coronaviridae family to cause a fatal disease in humans. There is currently only one antiviral compound, remdesivir, that can be used for the treatment of COVID-19. To identify additional potential therapeutics, we investigated the enzymatic proteins encoded in the SARS-CoV-2 genome. In this study, we focussed on the viral RNA cap methyltransferases, which play key roles in enabling viral protein translation and facilitating viral escape from the immune system. We expressed and purified both the guanine-N7 methyltransferase nsp14, and the nsp16 2'-O-methyltransferase with its activating cofactor, nsp10. We performed an in vitro high-throughput screen for inhibitors of nsp14 using a custom compound library of over 5000 pharmaceutical compounds that have previously been characterised in either clinical or basic research. We identified four compounds as potential inhibitors of nsp14, all of which also showed antiviral capacity in a cell-based model of SARS-CoV-2 infection. Three of the four compounds also exhibited synergistic effects on viral replication with remdesivir.


Subject(s)
Antiviral Agents/pharmacology , Drug Evaluation, Preclinical , Exoribonucleases/antagonists & inhibitors , Methyltransferases/antagonists & inhibitors , RNA Caps/metabolism , SARS-CoV-2/enzymology , Small Molecule Libraries/pharmacology , Viral Nonstructural Proteins/antagonists & inhibitors , Adenosine Monophosphate/analogs & derivatives , Adenosine Monophosphate/pharmacology , Alanine/analogs & derivatives , Alanine/pharmacology , Animals , Antiviral Agents/chemistry , Chlorobenzenes/pharmacology , Chlorocebus aethiops , Enzyme Assays , Exoribonucleases/genetics , Exoribonucleases/isolation & purification , Exoribonucleases/metabolism , Fluorescence Resonance Energy Transfer , High-Throughput Screening Assays , Indazoles/pharmacology , Indenes/pharmacology , Indoles/pharmacology , Methyltransferases/genetics , Methyltransferases/isolation & purification , Methyltransferases/metabolism , Nitriles/pharmacology , Phenothiazines/pharmacology , Purines/pharmacology , Reproducibility of Results , SARS-CoV-2/drug effects , Small Molecule Libraries/chemistry , Substrate Specificity , Trifluperidol/pharmacology , Vero Cells , Viral Nonstructural Proteins/genetics , Viral Nonstructural Proteins/isolation & purification , Viral Nonstructural Proteins/metabolism , Viral Regulatory and Accessory Proteins/genetics , Viral Regulatory and Accessory Proteins/isolation & purification , Viral Regulatory and Accessory Proteins/metabolism
12.
Future Med Chem ; 13(16): 1353-1366, 2021 08.
Article in English | MEDLINE | ID: covidwho-1282697

ABSTRACT

Background: The new coronavirus pandemic has had a significant impact worldwide, and therapeutic treatment for this viral infection is being strongly pursued. Efforts have been undertaken by medicinal chemists to discover molecules or known drugs that may be effective in COVID-19 treatment - in particular, targeting the main protease (Mpro) of the virus. Materials & methods: We have employed an innovative strategy - application of ligand- and structure-based virtual screening - using a special compilation of an approved and diverse set of SARS-CoV-2 crystallographic complexes that was recently published. Results and conclusion: We identified seven drugs with different original indications that might act as potential Mpro inhibitors and may be preferable to other drugs that have been repurposed. These drugs will be experimentally tested to confirm their potential Mpro inhibition and thus their effectiveness against COVID-19.


Subject(s)
Antiviral Agents/chemistry , COVID-19/drug therapy , Protease Inhibitors/chemistry , SARS-CoV-2/drug effects , Small Molecule Libraries/chemistry , Viral Proteases/metabolism , Antiviral Agents/pharmacology , Databases, Chemical , Drug Evaluation, Preclinical , Humans , Ligands , Molecular Docking Simulation , Molecular Structure , Protease Inhibitors/pharmacology , Protein Binding , Small Molecule Libraries/pharmacology , Structure-Activity Relationship
13.
Int J Mol Sci ; 22(12)2021 Jun 16.
Article in English | MEDLINE | ID: covidwho-1273456

ABSTRACT

Although the approved vaccines are proving to be of utmost importance in containing the Coronavirus disease 2019 (COVID-19) threat, they will hardly be resolutive as new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, a single-stranded RNA virus) variants might be insensitive to the immune response they induce. In this scenario, developing an effective therapy is still a dire need. Different targets for therapeutic antibodies and diagnostics have been identified, among which the SARS-CoV-2 spike (S) glycoprotein, particularly its receptor-binding domain, has been defined as crucial. In this context, we aim to focus attention also on the role played by the S N-terminal domain (S1-NTD) in the virus attachment, already recognized as a valuable target for neutralizing antibodies, in particular, building on a cavity mapping indicating the presence of two druggable pockets and on the recent literature hypothesizing the presence of a ganglioside-binding domain. In this perspective, we aim at proposing S1-NTD as a putative target for designing small molecules hopefully able to hamper the SARS-CoV-2 attachment to host cells.


Subject(s)
SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/metabolism , Binding Sites , COVID-19/pathology , COVID-19/therapy , COVID-19/virology , Drug Repositioning , Humans , Molecular Dynamics Simulation , N-Acetylneuraminic Acid/analogs & derivatives , N-Acetylneuraminic Acid/metabolism , N-Acetylneuraminic Acid/pharmacology , N-Acetylneuraminic Acid/therapeutic use , Protein Binding , Protein Domains , SARS-CoV-2/isolation & purification , Small Molecule Libraries/chemistry , Small Molecule Libraries/metabolism , Small Molecule Libraries/pharmacology , Small Molecule Libraries/therapeutic use , Spike Glycoprotein, Coronavirus/chemistry , Virus Attachment/drug effects
14.
SLAS Discov ; 26(9): 1091-1106, 2021 10.
Article in English | MEDLINE | ID: covidwho-1255878

ABSTRACT

Lung imaging and autopsy reports among COVID-19 patients show elevated lung scarring (fibrosis). Early data from COVID-19 patients as well as previous studies from severe acute respiratory syndrome, Middle East respiratory syndrome, and other respiratory disorders show that the extent of lung fibrosis is associated with a higher mortality, prolonged ventilator dependence, and poorer long-term health prognosis. Current treatments to halt or reverse lung fibrosis are limited; thus, the rapid development of effective antifibrotic therapies is a major global medical need that will continue far beyond the current COVID-19 pandemic. Reproducible fibrosis screening assays with high signal-to-noise ratios and disease-relevant readouts such as extracellular matrix (ECM) deposition (the hallmark of fibrosis) are integral to any antifibrotic therapeutic development. Therefore, we have established an automated high-throughput and high-content primary screening assay measuring transforming growth factor-ß (TGFß)-induced ECM deposition from primary human lung fibroblasts in a 384-well format. This assay combines longitudinal live cell imaging with multiparametric high-content analysis of ECM deposition. Using this assay, we have screened a library of 2743 small molecules representing approved drugs and late-stage clinical candidates. Confirmed hits were subsequently profiled through a suite of secondary lung fibroblast phenotypic screening assays quantifying cell differentiation, proliferation, migration, and apoptosis. In silico target prediction and pathway network analysis were applied to the confirmed hits. We anticipate this suite of assays and data analysis tools will aid the identification of new treatments to mitigate against lung fibrosis associated with COVID-19 and other fibrotic diseases.


Subject(s)
COVID-19/drug therapy , Drug Discovery , Lung/diagnostic imaging , Small Molecule Libraries/pharmacology , Apoptosis/drug effects , COVID-19/epidemiology , COVID-19/virology , Cell Differentiation/drug effects , Cell Movement/drug effects , Cell Proliferation/drug effects , Extracellular Matrix/drug effects , Extracellular Matrix/pathology , Fibroblasts/drug effects , Humans , Lung/drug effects , Lung/pathology , Lung/virology , Mass Screening , Pandemics , SARS-CoV-2/pathogenicity , Signal Transduction/drug effects
15.
Biomed Res Int ; 2021: 6696012, 2021.
Article in English | MEDLINE | ID: covidwho-1255651

ABSTRACT

A global pandemic has emerged following the appearance of the new severe acute respiratory virus whose official name is the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), strongly affecting the health sector as well as the world economy. Indeed, following the emergence of this new virus, despite the existence of a few approved and known effective vaccines at the time of writing this original study, a sense of urgency has emerged worldwide to discover new technical tools and new drugs as soon as possible. In this context, many studies and researches are currently underway to develop new tools and therapies against SARS CoV-2 and other viruses, using different approaches. The 3-chymotrypsin (3CL) protease, which is directly involved in the cotranslational and posttranslational modifications of viral polyproteins essential for the existence and replication of the virus in the host, is one of the coronavirus target proteins that has been the subject of these extensive studies. Currently, the majority of these studies are aimed at repurposing already known and clinically approved drugs against this new virus, but this approach is not really successful. Recently, different studies have successfully demonstrated the effectiveness of artificial intelligence-based techniques to understand existing chemical spaces and generate new small molecules that are both effective and efficient. In this framework and for our study, we combined a generative recurrent neural network model with transfer learning methods and active learning-based algorithms to design novel small molecules capable of effectively inhibiting the 3CL protease in human cells. We then analyze these small molecules to find the correct binding site that matches the structure of the 3CL protease of our target virus as well as other analyses performed in this study. Based on these screening results, some molecules have achieved a good binding score close to -18 kcal/mol, which we can consider as good potential candidates for further synthesis and testing against SARS-CoV-2.


Subject(s)
Antiviral Agents/chemistry , Biological Products/chemistry , Coronavirus 3C Proteases/antagonists & inhibitors , Neural Networks, Computer , Protease Inhibitors/chemistry , SARS-CoV-2/chemistry , Small Molecule Libraries/chemistry , Antiviral Agents/classification , Antiviral Agents/pharmacology , Biological Products/classification , Biological Products/pharmacology , COVID-19/drug therapy , Catalytic Domain , Coronavirus 3C Proteases/chemistry , Coronavirus 3C Proteases/genetics , Coronavirus 3C Proteases/metabolism , Drug Design , Gene Expression , Humans , Kinetics , Molecular Docking Simulation , Protease Inhibitors/classification , Protease Inhibitors/pharmacology , Protein Binding , Protein Interaction Domains and Motifs , Protein Structure, Secondary , SARS-CoV-2/drug effects , SARS-CoV-2/enzymology , Small Molecule Libraries/classification , Small Molecule Libraries/pharmacology , Substrate Specificity , Thermodynamics
16.
Mol Biol Rep ; 48(5): 4667-4675, 2021 May.
Article in English | MEDLINE | ID: covidwho-1237535

ABSTRACT

The transmembrane protease serine 2 (TMPRSS2) is a membrane anchored protease that primarily expressed by epithelial cells of respiratory and gastrointestinal systems and has been linked to multiple pathological processes in humans including tumor growth, metastasis and viral infections. Recent studies have shown that TMPRSS2 expressed on cell surface of host cells could play a crucial role in activation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein which facilitates the rapid early entry of the virus into host cells. In addition, direct suppression of TMPRSS2 using small drug inhibitors has been demonstrated to be effective in decreasing SARS-CoV-2 infection in vitro, which presents TMPRSS2 protease as a potential therapeutic strategy for SARS-CoV-2 infection. Recently, SARS-CoV-2 has been shown to be capable of infecting gastrointestinal enterocytes and to provoke gastrointestinal disorders in patients with COVID-19 disease, which is considered as a new transmission route and target organ of SARS-CoV-2. In this review, we highlight the biochemical properties of TMPRSS2 protease and discuss the potential targeting of TMPRSS2 by inhibitors to prevent the SARS-CoV-2 spreading through gastro-intestinal tract system as well as the hurdles that need to be overcome.


Subject(s)
COVID-19/metabolism , Enterocytes/drug effects , SARS-CoV-2/physiology , Serine Endopeptidases/metabolism , Serine Proteinase Inhibitors/pharmacology , Antiviral Agents/pharmacology , COVID-19/drug therapy , Drug Evaluation, Preclinical , Enterocytes/metabolism , Enterocytes/virology , Humans , SARS-CoV-2/drug effects , Small Molecule Libraries/pharmacology , Spike Glycoprotein, Coronavirus/metabolism , Virus Internalization/drug effects
17.
Bioorg Med Chem Lett ; 42: 128067, 2021 06 15.
Article in English | MEDLINE | ID: covidwho-1213059

ABSTRACT

The outbreak of coronavirus (CoV) disease 2019 (COVID-19) caused by the severe acute respiratory syndrome CoV-2 (SARS-CoV-2) has turned into a pandemic. The enzyme 3C-like protease (3CLpro) is essential for the maturation of viral polyproteins in SARS-CoV-2 and is therefore regarded as a key drug target for treating the disease. To identify 3CLpro inhibitors that can suppress SARS-CoV-2 replication, we performed a virtual screening of 500,282 compounds in a Korean compound bank. We then subjected the top computational hits to inhibitory assays against 3CLpro in vitro, leading to the identification of a class of non-covalent inhibitors. Among these inhibitors, compound 7 showed an EC50 of 39.89 µM against SARS-CoV-2 and CC50 of 453.5 µM. This study provides candidates for the optimization of potent 3CLpro inhibitors showing antiviral effects against SARS-CoV-2.


Subject(s)
Antiviral Agents/pharmacology , Coronavirus 3C Proteases/antagonists & inhibitors , Protease Inhibitors/pharmacology , SARS-CoV-2/enzymology , Small Molecule Libraries/pharmacology , Animals , Antiviral Agents/metabolism , Chlorocebus aethiops , Coronavirus 3C Proteases/metabolism , Drug Evaluation, Preclinical , Microbial Sensitivity Tests , Molecular Docking Simulation , Protease Inhibitors/metabolism , Protein Binding , Republic of Korea , Small Molecule Libraries/metabolism , Vero Cells
18.
PLoS One ; 16(4): e0250019, 2021.
Article in English | MEDLINE | ID: covidwho-1197380

ABSTRACT

SARS-CoV-2 has caused a global pandemic, and has taken over 1.7 million lives as of mid-December, 2020. Although great progress has been made in the development of effective countermeasures, with several pharmaceutical companies approved or poised to deliver vaccines to market, there is still an unmet need of essential antiviral drugs with therapeutic impact for the treatment of moderate-to-severe COVID-19. Towards this goal, a high-throughput assay was used to screen SARS-CoV-2 nsp15 uracil-dependent endonuclease (endoU) function against 13 thousand compounds from drug and lead repurposing compound libraries. While over 80% of initial hit compounds were pan-assay inhibitory compounds, three hits were confirmed as nsp15 endoU inhibitors in the 1-20 µM range in vitro. Furthermore, Exebryl-1, a ß-amyloid anti-aggregation molecule for Alzheimer's therapy, was shown to have antiviral activity between 10 to 66 µM, in Vero 76, Caco-2, and Calu-3 cells. Although the inhibitory concentrations determined for Exebryl-1 exceed those recommended for therapeutic intervention, our findings show great promise for further optimization of Exebryl-1 as an nsp15 endoU inhibitor and as a SARS-CoV-2 antiviral.


Subject(s)
Antiviral Agents/pharmacology , COVID-19/drug therapy , Drug Repositioning , Endoribonucleases/antagonists & inhibitors , SARS-CoV-2/drug effects , Small Molecule Libraries/pharmacology , Viral Nonstructural Proteins/antagonists & inhibitors , Animals , Antiviral Agents/chemistry , COVID-19/virology , Caco-2 Cells , Chlorocebus aethiops , Drug Repositioning/methods , Endoribonucleases/metabolism , High-Throughput Screening Assays/methods , Humans , Molecular Docking Simulation , SARS-CoV-2/metabolism , Small Molecule Libraries/chemistry , Vero Cells , Viral Nonstructural Proteins/metabolism
19.
SLAS Discov ; 26(6): 766-774, 2021 07.
Article in English | MEDLINE | ID: covidwho-1192708

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the virus responsible for the global COVID-19 pandemic. Nonstructural protein 14 (NSP14), which features exonuclease (ExoN) and guanine N7 methyltransferase activity, is a critical player in SARS-CoV-2 replication and fidelity and represents an attractive antiviral target. Initiating drug discovery efforts for nucleases such as NSP14 remains a challenge due to a lack of suitable high-throughput assay methodologies. This report describes the combination of self-assembled monolayers and matrix-assisted laser desorption ionization mass spectrometry to enable the first label-free and high-throughput assay for NSP14 ExoN activity. The assay was used to measure NSP14 activity and gain insight into substrate specificity and the reaction mechanism. Next, the assay was optimized for kinetically balanced conditions and miniaturized, while achieving a robust assay (Z factor > 0.8) and a significant assay window (signal-to-background ratio > 200). Screening 10,240 small molecules from a diverse library revealed candidate inhibitors, which were counterscreened for NSP14 selectivity and RNA intercalation. The assay methodology described here will enable, for the first time, a label-free and high-throughput assay for NSP14 ExoN activity to accelerate drug discovery efforts and, due to the assay flexibility, can be more broadly applicable for measuring other enzyme activities from other viruses or implicated in various pathologies.


Subject(s)
Antiviral Agents/pharmacology , Enzyme Inhibitors/pharmacology , Exonucleases/antagonists & inhibitors , Exoribonucleases/antagonists & inhibitors , High-Throughput Screening Assays , RNA, Viral/antagonists & inhibitors , SARS-CoV-2/drug effects , Viral Nonstructural Proteins/antagonists & inhibitors , Antiviral Agents/chemistry , COVID-19/virology , Cloning, Molecular , Enzyme Assays , Enzyme Inhibitors/chemistry , Escherichia coli/genetics , Escherichia coli/metabolism , Exonucleases/genetics , Exonucleases/metabolism , Exoribonucleases/genetics , Exoribonucleases/metabolism , Gene Expression , Genetic Vectors/chemistry , Genetic Vectors/metabolism , Humans , Kinetics , RNA, Viral/genetics , RNA, Viral/metabolism , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , SARS-CoV-2/enzymology , SARS-CoV-2/genetics , Small Molecule Libraries/chemistry , Small Molecule Libraries/pharmacology , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Substrate Specificity , Viral Nonstructural Proteins/genetics , Viral Nonstructural Proteins/metabolism , Virus Replication/drug effects
20.
Bioorg Med Chem ; 38: 116119, 2021 05 15.
Article in English | MEDLINE | ID: covidwho-1157155

ABSTRACT

In response to the pandemic caused by SARS-CoV-2, we constructed a hybrid support vector machine (SVM) classification model using a set of publicly posted SARS-CoV-2 pseudotyped particle (PP) entry assay repurposing screen data to identify novel potent compounds as a starting point for drug development to treat COVID-19 patients. Two different molecular descriptor systems, atom typing descriptors and 3D fingerprints (FPs), were employed to construct the SVM classification models. Both models achieved reasonable performance, with the area under the curve of receiver operating characteristic (AUC-ROC) of 0.84 and 0.82, respectively. The consensus prediction outperformed the two individual models with significantly improved AUC-ROC of 0.91, where the compounds with inconsistent classifications were excluded. The consensus model was then used to screen the 173,898 compounds in the NCATS annotated and diverse chemical libraries. Of the 255 compounds selected for experimental confirmation, 116 compounds exhibited inhibitory activities in the SARS-CoV-2 PP entry assay with IC50 values ranged between 0.17 µM and 62.2 µM, representing an enrichment factor of 3.2. These 116 active compounds with diverse and novel structures could potentially serve as starting points for chemistry optimization for COVID-19 drug discovery.


Subject(s)
Antiviral Agents/pharmacology , SARS-CoV-2/drug effects , Support Vector Machine/statistics & numerical data , Virus Internalization/drug effects , Area Under Curve , Databases, Chemical/statistics & numerical data , Drug Repositioning , HEK293 Cells , Humans , Microbial Sensitivity Tests , ROC Curve , Small Molecule Libraries/pharmacology
SELECTION OF CITATIONS
SEARCH DETAIL
...