Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 45
Filter
1.
Bioorg Chem ; 129: 106185, 2022 12.
Article in English | MEDLINE | ID: covidwho-2060449

ABSTRACT

The evolving SARS-CoV-2 epidemic buffets the world, and the concerted efforts are needed to explore effective drugs. Mpro is an intriguing antiviral target for interfering with viral RNA replication and transcription. In order to get potential anti-SARS-CoV-2 agents, we established an enzymatic assay using a fluorogenic substrate to screen the inhibitors of Mpro. Fortunately, Acriflavine (ACF) and Proflavine Hemisulfate (PRF) with the same acridine scaffold were picked out for their good inhibitory activity against Mpro with IC50 of 5.60 ± 0.29 µM and 2.07 ± 0.01 µM, respectively. Further evaluation of MST assay and enzymatic kinetics experiment in vitro showed that they had a certain affinity to SARS-CoV-2 Mpro and were both non-competitive inhibitors. In addition, they inhibited about 90 % HCoV-OC43 replication in BHK-21 cells at 1 µM. Both compounds showed nano-molar activities against SARS-CoV-2 virus, which were superior to GC376 for anti-HCoV-43, and equivalent to the standard molecule remdesivir. Our study demonstrated that ACF and PRF were inhibitors of Mpro, and ACF has been previously reported as a PLpro inhibitor. Taken together, ACF and PRF might be dual-targeted inhibitors to provide protection against infections of coronaviruses.


Subject(s)
Acriflavine , COVID-19 , Coronavirus 3C Proteases , Cysteine Proteinase Inhibitors , Proflavine , SARS-CoV-2 , Viral Protease Inhibitors , Acriflavine/pharmacology , COVID-19/drug therapy , Proflavine/pharmacology , SARS-CoV-2/drug effects , SARS-CoV-2/enzymology , Coronavirus 3C Proteases/antagonists & inhibitors , Cysteine Proteinase Inhibitors/pharmacology , Viral Protease Inhibitors/pharmacology , Mesocricetus , Animals , Cricetinae , Cell Line , Virus Replication/drug effects
2.
Int J Mol Sci ; 23(16)2022 Aug 12.
Article in English | MEDLINE | ID: covidwho-2023734

ABSTRACT

Heavy metal ions can disrupt biological functions via multiple molecular mechanisms, including inhibition of enzymes. We investigate the interactions of human papain-like cysteine endopeptidases cathepsins L, K, and S with gallium and cerium ions, which are associated with medical applications. We compare these results with zinc and lead, which are known to inhibit thiol enzymes. We show that Ga3+, Ce3+, and Ce4+ ions inhibit all tested peptidases with inhibition constants in the low micromolar range (between 0.5 µM and 10 µM) which is comparable to Zn2+ ions, whereas inhibition constants of Pb2+ ions are one order of magnitude higher (30 µM to 150 µM). All tested ions are linear specific inhibitors of cathepsin L, but cathepsins K and S are inhibited by Ga3+, Ce3+, and Ce4+ ions via hyperbolic inhibition mechanisms. This indicates a mode of interaction different from that of Zn2+ and Pb2+ ions, which act as linear specific inhibitors of all peptidases. All ions also inhibit the degradation of insoluble elastin, which is a common target of these peptidases in various inflammatory diseases. Our results suggest that these ions and their compounds have the potential to be used as cysteine cathepsin inhibitors in vitro and possibly in vivo.


Subject(s)
Cerium , Gallium , Cathepsin K/metabolism , Cathepsins/metabolism , Cysteine , Cysteine Proteinase Inhibitors/metabolism , Cysteine Proteinase Inhibitors/pharmacology , Endopeptidases/metabolism , Humans , Ions , Kinetics , Lead
3.
Molecules ; 27(8)2022 Apr 15.
Article in English | MEDLINE | ID: covidwho-1810043

ABSTRACT

In the field of drug discovery, the nitrile group is well represented among drugs and biologically active compounds. It can form both non-covalent and covalent interactions with diverse biological targets, and it is amenable as an electrophilic warhead for covalent inhibition. The main advantage of the nitrile group as a warhead is mainly due to its milder electrophilic character relative to other more reactive groups (e.g., -CHO), reducing the possibility of unwanted reactions that would hinder the development of safe drugs, coupled to the ease of installation through different synthetic approaches. The covalent inhibition is a well-assessed design approach for serine, threonine, and cysteine protease inhibitors. The mechanism of hydrolysis of these enzymes involves the formation of a covalent acyl intermediate, and this mechanism can be exploited by introducing electrophilic warheads in order to mimic this covalent intermediate. Due to the relevant role played by the cysteine protease in the survival and replication of infective agents, spanning from viruses to protozoan parasites, we will review the most relevant and recent examples of protease inhibitors presenting a nitrile group that have been introduced to form or to facilitate the formation of a covalent bond with the catalytic cysteine active site residue.


Subject(s)
Cysteine Proteases , Parasitic Diseases , Cysteine/chemistry , Cysteine Proteinase Inhibitors/pharmacology , Drug Discovery , Humans , Nitriles/pharmacology
4.
J Med Chem ; 65(4): 2880-2904, 2022 02 24.
Article in English | MEDLINE | ID: covidwho-1705973

ABSTRACT

Starting from the MLPCN probe compound ML300, a structure-based optimization campaign was initiated against the recent severe acute respiratory syndrome coronavirus (SARS-CoV-2) main protease (3CLpro). X-ray structures of SARS-CoV-1 and SARS-CoV-2 3CLpro enzymes in complex with multiple ML300-based inhibitors, including the original probe ML300, were obtained and proved instrumental in guiding chemistry toward probe compound 41 (CCF0058981). The disclosed inhibitors utilize a noncovalent mode of action and complex in a noncanonical binding mode not observed by peptidic 3CLpro inhibitors. In vitro DMPK profiling highlights key areas where further optimization in the series is required to obtain useful in vivo probes. Antiviral activity was established using a SARS-CoV-2-infected Vero E6 cell viability assay and a plaque formation assay. Compound 41 demonstrates nanomolar activity in these respective assays, comparable in potency to remdesivir. These findings have implications for antiviral development to combat current and future SARS-like zoonotic coronavirus outbreaks.


Subject(s)
Antiviral Agents/pharmacology , Coronavirus 3C Proteases/antagonists & inhibitors , Cysteine Proteinase Inhibitors/pharmacology , Peptidomimetics/pharmacology , SARS-CoV-2/drug effects , Animals , Antiviral Agents/chemical synthesis , Antiviral Agents/chemistry , COVID-19/drug therapy , COVID-19/metabolism , Chlorocebus aethiops , Coronavirus 3C Proteases/isolation & purification , Coronavirus 3C Proteases/metabolism , Crystallography, X-Ray , Cysteine Proteinase Inhibitors/chemical synthesis , Cysteine Proteinase Inhibitors/chemistry , Dose-Response Relationship, Drug , Glutamine/chemistry , Glutamine/pharmacology , Humans , Ketones/chemistry , Ketones/pharmacology , Microbial Sensitivity Tests , Models, Molecular , Molecular Structure , Peptidomimetics/chemistry , SARS-CoV-2/enzymology , Vero Cells , Virus Replication/drug effects
5.
J Am Chem Soc ; 144(7): 2905-2920, 2022 02 23.
Article in English | MEDLINE | ID: covidwho-1683927

ABSTRACT

Drugs targeting SARS-CoV-2 could have saved millions of lives during the COVID-19 pandemic, and it is now crucial to develop inhibitors of coronavirus replication in preparation for future outbreaks. We explored two virtual screening strategies to find inhibitors of the SARS-CoV-2 main protease in ultralarge chemical libraries. First, structure-based docking was used to screen a diverse library of 235 million virtual compounds against the active site. One hundred top-ranked compounds were tested in binding and enzymatic assays. Second, a fragment discovered by crystallographic screening was optimized guided by docking of millions of elaborated molecules and experimental testing of 93 compounds. Three inhibitors were identified in the first library screen, and five of the selected fragment elaborations showed inhibitory effects. Crystal structures of target-inhibitor complexes confirmed docking predictions and guided hit-to-lead optimization, resulting in a noncovalent main protease inhibitor with nanomolar affinity, a promising in vitro pharmacokinetic profile, and broad-spectrum antiviral effect in infected cells.


Subject(s)
Antiviral Agents/pharmacology , Coronavirus 3C Proteases/metabolism , Cysteine Proteinase Inhibitors/pharmacology , SARS-CoV-2/drug effects , Small Molecule Libraries/pharmacology , Animals , Antiviral Agents/metabolism , Antiviral Agents/pharmacokinetics , Catalytic Domain , Chlorocebus aethiops , Coronavirus 3C Proteases/chemistry , Cysteine Proteinase Inhibitors/metabolism , Cysteine Proteinase Inhibitors/pharmacokinetics , Drug Evaluation, Preclinical , Humans , Microbial Sensitivity Tests , Microsomes, Liver/metabolism , Molecular Docking Simulation , Protein Binding , SARS-CoV-2/enzymology , Small Molecule Libraries/metabolism , Small Molecule Libraries/pharmacokinetics , Vero Cells
6.
SLAS Discov ; 27(1): 8-19, 2022 01.
Article in English | MEDLINE | ID: covidwho-1641663

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 responsible for COVID-19 remains a persistent threat to mankind, especially for the immunocompromised and elderly for which the vaccine may have limited effectiveness. Entry of SARS-CoV-2 requires a high affinity interaction of the viral spike protein with the cellular receptor angiotensin-converting enzyme 2. Novel mutations on the spike protein correlate with the high transmissibility of new variants of SARS-CoV-2, highlighting the need for small molecule inhibitors of virus entry into target cells. We report the identification of such inhibitors through a robust high-throughput screen testing 15,000 small molecules from unique libraries. Several leads were validated in a suite of mechanistic assays, including whole cell SARS-CoV-2 infectivity assays. The main lead compound, calpeptin, was further characterized using SARS-CoV-1 and the novel SARS-CoV-2 variant entry assays, SARS-CoV-2 protease assays and molecular docking. This study reveals calpeptin as a potent and specific inhibitor of SARS-CoV-2 and some variants.


Subject(s)
Antiviral Agents/pharmacology , COVID-19/drug therapy , Cysteine Proteinase Inhibitors/pharmacology , Dipeptides/pharmacology , Virus Attachment/drug effects , Virus Internalization/drug effects , Angiotensin-Converting Enzyme 2/metabolism , Animals , Cathepsin L/antagonists & inhibitors , Cell Line , Chlorocebus aethiops , Drug Evaluation, Preclinical , Drug Repositioning , HEK293 Cells , Humans , Molecular Docking Simulation , SARS-CoV-2/drug effects , SARS-CoV-2/growth & development , Serine Endopeptidases/metabolism , Spike Glycoprotein, Coronavirus/metabolism , Vero Cells
7.
Bioengineered ; 13(2): 3350-3361, 2022 02.
Article in English | MEDLINE | ID: covidwho-1632167

ABSTRACT

The COVID-19 new variants spread rapidly all over the world, and until now scientists strive to find virus-specific antivirals for its treatment. The main protease of SARS-CoV-2 (Mpro) exhibits high structural and sequence homology to main protease of SARS-CoV (93.23% sequence identity), and their sequence alignment indicated 12 mutated/variant residues. The sequence alignment of SARS-CoV-2 main protease led to identification of only one mutated/variant residue with no significant role in its enzymatic process. Therefore, Mpro was considered as a high-profile drug target in anti-SARS-CoV-2 drug discovery. Apigenin analogues to COVID-19 main protease binding were evaluated. The detailed interactions between the analogues of Apigenin and SARS-CoV-2 Mpro inhibitors were determined as hydrogen bonds, electronic bonds and hydrophobic interactions. The binding energies obtained from the molecular docking of Mpro with Boceprevir, Apigenin, Apigenin 7-glucoside-4'-p-coumarate, Apigenin 7-glucoside-4'-trans-caffeate and Apigenin 7-O-beta-d-glucoside (Cosmosiin) were found to be -6.6, -7.2, -8.8, -8.7 and -8.0 kcal/mol, respectively. Pharmacokinetic parameters and toxicological characteristics obtained by computational techniques and Virtual ADME studies of the Apigenin analogues confirmed that the Apigenin 7-glucoside-4'-p-coumarate is the best candidate for SARS-CoV-2 Mpro inhibition.


Subject(s)
Antiviral Agents/pharmacology , Apigenin/pharmacology , COVID-19/drug therapy , Coronavirus 3C Proteases/antagonists & inhibitors , Cysteine Proteinase Inhibitors/pharmacology , SARS-CoV-2/drug effects , SARS-CoV-2/enzymology , Amino Acid Sequence , Antiviral Agents/chemistry , Antiviral Agents/pharmacokinetics , Apigenin/chemistry , Apigenin/pharmacokinetics , Bioengineering , COVID-19/virology , Computer Simulation , Coronavirus 3C Proteases/chemistry , Coronavirus 3C Proteases/genetics , Cysteine Proteinase Inhibitors/chemistry , Cysteine Proteinase Inhibitors/pharmacokinetics , Drug Evaluation, Preclinical , Glucosides/chemistry , Glucosides/pharmacokinetics , Glucosides/pharmacology , Humans , Molecular Docking Simulation , Phytotherapy , Protein Domains , SARS-CoV-2/genetics
8.
ChemMedChem ; 17(1): e202100576, 2022 01 05.
Article in English | MEDLINE | ID: covidwho-1626179

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic is an unprecedented global health emergency causing more than 4.2 million fatalities as of 30 July 2021. Only three antiviral therapies have been approved or granted emergency use authorization by the FDA. The SARS-CoV-2 3CL protease (3CLpro ) is deemed an attractive drug target as it plays an essential role in viral polyprotein processing and pathogenesis, although no inhibitors have been approved. This patent review discusses SARS coronavirus 3CLpro inhibitors that have been filed up to 30 July 2021, giving an overview on the types of inhibitors that have generated commercial interest, especially amongst drug companies. Insights into the common structural motifs required for active site binding is also discussed.


Subject(s)
Antiviral Agents/pharmacology , Coronavirus 3C Proteases/antagonists & inhibitors , Cysteine Proteinase Inhibitors/pharmacology , Patents as Topic , Antiviral Agents/chemistry , Cysteine Proteinase Inhibitors/chemistry , Drug Discovery , Humans , Protein Conformation , Structure-Activity Relationship
9.
J Med Chem ; 64(24): 17846-17865, 2021 12 23.
Article in English | MEDLINE | ID: covidwho-1555306

ABSTRACT

The COVID-19 pandemic is having a major impact on public health worldwide, and there is an urgent need for the creation of an armamentarium of effective therapeutics, including vaccines, biologics, and small-molecule therapeutics, to combat SARS-CoV-2 and emerging variants. Inspection of the virus life cycle reveals multiple viral- and host-based choke points that can be exploited to combat the virus. SARS-CoV-2 3C-like protease (3CLpro), an enzyme essential for viral replication, is an attractive target for therapeutic intervention, and the design of inhibitors of the protease may lead to the emergence of effective SARS-CoV-2-specific antivirals. We describe herein the results of our studies related to the application of X-ray crystallography, the Thorpe-Ingold effect, deuteration, and stereochemistry in the design of highly potent and nontoxic inhibitors of SARS-CoV-2 3CLpro.


Subject(s)
Antiviral Agents/pharmacology , Coronavirus 3C Proteases/antagonists & inhibitors , Cysteine Proteinase Inhibitors/pharmacology , SARS-CoV-2/drug effects , Animals , Antiviral Agents/chemical synthesis , Antiviral Agents/metabolism , Chlorocebus aethiops , Coronavirus 3C Proteases/metabolism , Crystallography, X-Ray , Cysteine Proteinase Inhibitors/chemical synthesis , Cysteine Proteinase Inhibitors/metabolism , Drug Design , HEK293 Cells , Humans , Hydrogen Bonding , Microbial Sensitivity Tests , Molecular Structure , Protein Binding , SARS-CoV-2/enzymology , Stereoisomerism , Vero Cells
10.
Viruses ; 13(8)2021 08 23.
Article in English | MEDLINE | ID: covidwho-1524167

ABSTRACT

The pandemic of COVID-19 caused by SARS-CoV-2 continues to spread despite the global efforts taken to control it. The 3C-like protease (3CLpro), the major protease of SARS-CoV-2, is one of the most interesting targets for antiviral drug development because it is highly conserved among SARS-CoVs and plays an important role in viral replication. Herein, we developed high throughput screening for SARS-CoV-2 3CLpro inhibitor based on AlphaScreen. We screened 91 natural product compounds and found that all-trans retinoic acid (ATRA), an FDA-approved drug, inhibited 3CLpro activity. The 3CLpro inhibitory effect of ATRA was confirmed in vitro by both immunoblotting and AlphaScreen with a 50% inhibition concentration (IC50) of 24.7 ± 1.65 µM. ATRA inhibited the replication of SARS-CoV-2 in VeroE6/TMPRSS2 and Calu-3 cells, with IC50 = 2.69 ± 0.09 µM in the former and 0.82 ± 0.01 µM in the latter. Further, we showed the anti-SARS-CoV-2 effect of ATRA on the currently circulating variants of concern (VOC); alpha, beta, gamma, and delta. These results suggest that ATRA may be considered as a potential therapeutic agent against SARS-CoV-2.


Subject(s)
Antiviral Agents/pharmacology , Coronavirus 3C Proteases/antagonists & inhibitors , SARS-CoV-2/drug effects , Tretinoin/pharmacology , Animals , Cell Line, Tumor , Chlorocebus aethiops , Cysteine Proteinase Inhibitors/pharmacology , DEAD Box Protein 58/metabolism , High-Throughput Screening Assays , Humans , Receptors, Immunologic/metabolism , SARS-CoV-2/enzymology , SARS-CoV-2/physiology , Vero Cells , Virus Replication/drug effects
11.
J Med Chem ; 65(4): 2956-2970, 2022 02 24.
Article in English | MEDLINE | ID: covidwho-1500413

ABSTRACT

Cathepsin L is a key host cysteine protease utilized by coronaviruses for cell entry and is a promising drug target for novel antivirals against SARS-CoV-2. The marine natural product gallinamide A and several synthetic analogues were identified as potent inhibitors of cathepsin L with IC50 values in the picomolar range. Lead molecules possessed selectivity over other cathepsins and alternative host proteases involved in viral entry. Gallinamide A directly interacted with cathepsin L in cells and, together with two lead analogues, potently inhibited SARS-CoV-2 infection in vitro, with EC50 values in the nanomolar range. Reduced antiviral activity was observed in cells overexpressing transmembrane protease, serine 2 (TMPRSS2); however, a synergistic improvement in antiviral activity was achieved when combined with a TMPRSS2 inhibitor. These data highlight the potential of cathepsin L as a COVID-19 drug target as well as the likely need to inhibit multiple routes of viral entry to achieve efficacy.


Subject(s)
Antimicrobial Cationic Peptides/pharmacology , Antiviral Agents/pharmacology , Biological Products/pharmacology , COVID-19/drug therapy , Cathepsin L/antagonists & inhibitors , Cysteine Proteinase Inhibitors/pharmacology , SARS-CoV-2/drug effects , A549 Cells , Animals , Antimicrobial Cationic Peptides/chemical synthesis , Antimicrobial Cationic Peptides/chemistry , Antiviral Agents/chemical synthesis , Antiviral Agents/chemistry , Biological Products/chemical synthesis , Biological Products/chemistry , COVID-19/metabolism , Cathepsin L/metabolism , Chlorocebus aethiops , Cysteine Proteinase Inhibitors/chemical synthesis , Cysteine Proteinase Inhibitors/chemistry , Dose-Response Relationship, Drug , Humans , Microbial Sensitivity Tests , Molecular Conformation , Proteomics , Structure-Activity Relationship , Vero Cells
12.
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
13.
J Med Chem ; 65(4): 2940-2955, 2022 02 24.
Article in English | MEDLINE | ID: covidwho-1475245

ABSTRACT

Antiviral agents that complement vaccination are urgently needed to end the COVID-19 pandemic. The SARS-CoV-2 papain-like protease (PLpro), one of only two essential cysteine proteases that regulate viral replication, also dysregulates host immune sensing by binding and deubiquitination of host protein substrates. PLpro is a promising therapeutic target, albeit challenging owing to featureless P1 and P2 sites recognizing glycine. To overcome this challenge, we leveraged the cooperativity of multiple shallow binding sites on the PLpro surface, yielding novel 2-phenylthiophenes with nanomolar inhibitory potency. New cocrystal structures confirmed that ligand binding induces new interactions with PLpro: by closing of the BL2 loop of PLpro forming a novel "BL2 groove" and by mimicking the binding interaction of ubiquitin with Glu167 of PLpro. Together, this binding cooperativity translates to the most potent PLpro inhibitors reported to date, with slow off-rates, improved binding affinities, and low micromolar antiviral potency in SARS-CoV-2-infected human cells.


Subject(s)
Antiviral Agents/pharmacology , COVID-19/drug therapy , Coronavirus Papain-Like Proteases/antagonists & inhibitors , Cysteine Proteinase Inhibitors/pharmacology , Antiviral Agents/chemical synthesis , Antiviral Agents/chemistry , Binding Sites/drug effects , COVID-19/metabolism , Coronavirus Papain-Like Proteases/isolation & purification , Coronavirus Papain-Like Proteases/metabolism , Crystallography, X-Ray , Cysteine Proteinase Inhibitors/chemical synthesis , Cysteine Proteinase Inhibitors/chemistry , Humans , Microbial Sensitivity Tests , Microsomes, Liver/chemistry , Microsomes, Liver/metabolism , Models, Molecular , Pandemics , Surface Plasmon Resonance , Tumor Cells, Cultured
14.
J Med Chem ; 65(4): 2866-2879, 2022 02 24.
Article in English | MEDLINE | ID: covidwho-1440451

ABSTRACT

The emergence of a new coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), presents an urgent public health crisis. Without available targeted therapies, treatment options remain limited for COVID-19 patients. Using medicinal chemistry and rational drug design strategies, we identify a 2-phenyl-1,2-benzoselenazol-3-one class of compounds targeting the SARS-CoV-2 main protease (Mpro). FRET-based screening against recombinant SARS-CoV-2 Mpro identified six compounds that inhibit proteolysis with nanomolar IC50 values. Preincubation dilution experiments and molecular docking determined that the inhibition of SARS-CoV-2 Mpro can occur by either covalent or noncovalent mechanisms, and lead E04 was determined to inhibit Mpro competitively. Lead E24 inhibited viral replication with a nanomolar EC50 value (844 nM) in SARS-CoV-2-infected Vero E6 cells and was further confirmed to impair SARS-CoV-2 replication in human lung epithelial cells and human-induced pluripotent stem cell-derived 3D lung organoids. Altogether, these studies provide a structural framework and mechanism of Mpro inhibition that should facilitate the design of future COVID-19 treatments.


Subject(s)
Antiviral Agents/pharmacology , Benzothiazoles/pharmacology , Coronavirus 3C Proteases/antagonists & inhibitors , Cysteine Proteinase Inhibitors/pharmacology , Drug Discovery , SARS-CoV-2/drug effects , Animals , Antiviral Agents/chemical synthesis , Antiviral Agents/chemistry , Benzothiazoles/chemistry , COVID-19/drug therapy , COVID-19/metabolism , Chlorocebus aethiops , Coronavirus 3C Proteases/isolation & purification , Coronavirus 3C Proteases/metabolism , Crystallography, X-Ray , Cysteine Proteinase Inhibitors/chemical synthesis , Cysteine Proteinase Inhibitors/chemistry , Dose-Response Relationship, Drug , Fluorescence Resonance Energy Transfer , Humans , Microbial Sensitivity Tests , Molecular Docking Simulation , Molecular Structure , SARS-CoV-2/enzymology , Vero Cells , Virus Replication/drug effects
16.
ACS Chem Biol ; 16(4): 642-650, 2021 04 16.
Article in English | MEDLINE | ID: covidwho-1387141

ABSTRACT

Host-cell cysteine proteases play an essential role in the processing of the viral spike protein of SARS coronaviruses. K777, an irreversible, covalent inactivator of cysteine proteases that has recently completed phase 1 clinical trials, reduced SARS-CoV-2 viral infectivity in several host cells: Vero E6 (EC50< 74 nM), HeLa/ACE2 (4 nM), Caco-2 (EC90 = 4.3 µM), and A549/ACE2 (<80 nM). Infectivity of Calu-3 cells depended on the cell line assayed. If Calu-3/2B4 was used, EC50 was 7 nM, but in the ATCC Calu-3 cell line without ACE2 enrichment, EC50 was >10 µM. There was no toxicity to any of the host cell lines at 10-100 µM K777 concentration. Kinetic analysis confirmed that K777 was a potent inhibitor of human cathepsin L, whereas no inhibition of the SARS-CoV-2 cysteine proteases (papain-like and 3CL-like protease) was observed. Treatment of Vero E6 cells with a propargyl derivative of K777 as an activity-based probe identified human cathepsin B and cathepsin L as the intracellular targets of this molecule in both infected and uninfected Vero E6 cells. However, cleavage of the SARS-CoV-2 spike protein was only carried out by cathepsin L. This cleavage was blocked by K777 and occurred in the S1 domain of the SARS-CoV-2 spike protein, a different site from that previously observed for the SARS-CoV-1 spike protein. These data support the hypothesis that the antiviral activity of K777 is mediated through inhibition of the activity of host cathepsin L and subsequent loss of cathepsin L-mediated viral spike protein processing.


Subject(s)
Antiviral Agents/pharmacology , Cysteine Proteinase Inhibitors/pharmacology , Phenylalanine/pharmacology , Piperazines/pharmacology , SARS-CoV-2/drug effects , Tosyl Compounds/pharmacology , Animals , Cathepsin L/antagonists & inhibitors , Cathepsin L/metabolism , Cell Line, Tumor , Chlorocebus aethiops , Humans , Microbial Sensitivity Tests , Protein Domains , Proteolysis , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/metabolism , Vero Cells , Virus Internalization/drug effects
17.
Mol Biotechnol ; 64(1): 1-8, 2022 Jan.
Article in English | MEDLINE | ID: covidwho-1366408

ABSTRACT

Because of the essential roles of SARS-CoV-2 papain-like protease (PLpro) in the viral polyprotein processing and suppression of host immune responses, it is a crucial target for drug discovery against COVID-19. To develop robust biochemical methodologies for inhibitor screening against PLpro, extensive characterization of recombinant protein is important. Here we report cloning, expression, and purification of the recombinant SARS-CoV-2 PLpro, and explore various parameters affecting its stability and the catalytic activity. We also report the optimum conditions which should be used for high-throughput inhibitor screening using a fluorogenic tetrapeptide substrate.


Subject(s)
Coronavirus Papain-Like Proteases/chemistry , Coronavirus Papain-Like Proteases/metabolism , High-Throughput Screening Assays/methods , Antiviral Agents/pharmacology , Coronavirus Papain-Like Proteases/antagonists & inhibitors , Coronavirus Papain-Like Proteases/isolation & purification , Coumarins/chemistry , Coumarins/metabolism , Cysteine Proteinase Inhibitors/pharmacology , Dimethyl Sulfoxide/chemistry , Dynamic Light Scattering , Edetic Acid/chemistry , Enzyme Stability , Fluorometry/methods , Hydrogen-Ion Concentration , Osmolar Concentration , Peptides/chemistry , Peptides/metabolism , Temperature
18.
ChemMedChem ; 17(1): e202100455, 2022 01 05.
Article in English | MEDLINE | ID: covidwho-1366225

ABSTRACT

As the pathogen of COVID-19, SARS-CoV-2 encodes two essential cysteine proteases that process the pathogen's two large polypeptide products pp1a and pp1ab in the human cell host to form 15 functionally important, mature nonstructural proteins. One of the two enzymes is papain-like protease or PLPro . It possesses deubiquitination and deISGylation activities that suppress host innate immune responses toward SARS-CoV-2 infection. To repurpose drugs for PLPro , we experimentally screened libraries of 33 deubiquitinase and 37 cysteine protease inhibitors on their inhibition of PLPro . Our results showed that 15 deubiquitinase and 1 cysteine protease inhibitors exhibit strong inhibition of PLPro at 200 µM. More comprehensive characterizations revealed seven inhibitors GRL0617, SJB2-043, TCID, DUB-IN-1, DUB-IN-3, PR-619, and S130 with an IC50 value below 40 µM and four inhibitors GRL0617, SJB2-043, TCID, and PR-619 with an IC50 value below 10 µM. Among four inhibitors with an IC50 value below 10 µM, SJB2-043 is the most unique in that it does not fully inhibit PLPro but has a noteworthy IC50 value of 0.56 µM. SJB2-043 likely binds to an allosteric site of PLPro to convene its inhibition effect, which needs to be further investigated. As a pilot study, the current work indicates that COVID-19 drug repurposing by targeting PLPro holds promise, but in-depth analysis of repurposed drugs is necessary to avoid omitting critical allosteric inhibitors.


Subject(s)
Antiviral Agents/pharmacology , Coronavirus Papain-Like Proteases/antagonists & inhibitors , Cysteine Proteinase Inhibitors/pharmacology , Drug Repositioning , SARS-CoV-2/drug effects , Antiviral Agents/chemistry , Cysteine Proteinase Inhibitors/chemistry , Humans , Inhibitory Concentration 50 , Structure-Activity Relationship
19.
Molecules ; 26(16)2021 Aug 05.
Article in English | MEDLINE | ID: covidwho-1362396

ABSTRACT

The specificity of inhibition by 6,6'-dihydroxythiobinupharidine (DTBN) on cysteine proteases was demonstrated in this work. There were differences in the extent of inhibition, reflecting active site structural-steric and biochemical differences. Cathepsin S (IC50 = 3.2 µM) was most sensitive to inhibition by DTBN compared to Cathepsin B, L and papain (IC50 = 1359.4, 13.2 and 70.4 µM respectively). DTBN is inactive for the inhibition of Mpro of SARS-CoV-2. Docking simulations suggested a mechanism of interaction that was further supported by the biochemical results. In the docking results, it was shown that the cysteine sulphur of Cathepsin S, L and B was in close proximity to the DTBN thiaspirane ring, potentially forming the necessary conditions for a nucleophilic attack to form a disulfide bond. Covalent docking and molecular dynamic simulations were performed to validate disulfide bond formation and to determine the stability of Cathepsins-DTBN complexes, respectively. The lack of reactivity of DTBN against SARS-CoV-2 Mpro was attributed to a mismatch of the binding conformation of DTBN to the catalytic binding site of Mpro. Thus, gradations in reactivity among the tested Cathepsins may be conducive for a mechanism-based search for derivatives of nupharidine against COVID-19. This could be an alternative strategy to the large-scale screening of electrophilic inhibitors.


Subject(s)
Alkaloids/pharmacology , Cysteine Proteases/metabolism , Alkaloids/chemistry , Animals , Antiviral Agents/pharmacology , Binding Sites , COVID-19/drug therapy , COVID-19/metabolism , Catalytic Domain , Cathepsins/pharmacology , Cell Line, Tumor , Cysteine Proteases/chemistry , Cysteine Proteinase Inhibitors/chemistry , Cysteine Proteinase Inhibitors/pharmacology , Humans , Mice , Molecular Docking Simulation/methods , Nuphar/chemistry , Papain/pharmacology , Plant Extracts/pharmacology , Protein Binding , SARS-CoV-2/drug effects
20.
Bioorg Med Chem ; 46: 116301, 2021 09 15.
Article in English | MEDLINE | ID: covidwho-1333256

ABSTRACT

Severe Acute Respiratory Syndrome (SARS) is a severe febrile respiratory disease caused by the beta genus of human coronavirus, known as SARS-CoV. Last year, 2019-n-CoV (COVID-19) was a global threat for everyone caused by the outbreak of SARS-CoV-2. 3CLpro, chymotrypsin-like protease, is a major cysteine protease that substantially contributes throughout the viral life cycle of SARS-CoV and SARS-CoV-2. It is a prospective target for the development of SARS-CoV inhibitors by applying a repurposing strategy. This review focuses on a detailed overview of the chemical synthesis and computational chemistry perspectives of peptidomimetic inhibitors (PIs) and small-molecule inhibitors (SMIs) targeting viral proteinase discovered from 2004 to 2020. The PIs and SMIs are one of the primary therapeutic inventions for SARS-CoV. The journey of different analogues towards the evolution of SARS-CoV 3CLpro inhibitors and complete synthetic preparation of nineteen derivatives of PIs and ten derivatives of SMIs and their computational chemistry perspectives were reviewed. From each class of derivatives, we have identified and highlighted the most compelling PIs and SMIs for SARS-CoV 3CLpro. The protein-ligand interaction of 29 inhibitors were also studied that involved with the 3CLpro inhibition, and the frequent amino acid residues of the protease were also analyzed that are responsible for the interactions with the inhibitors. This work will provide an initiative to encourage further research for the development of effective and drug-like 3CLpro inhibitors against coronaviruses in the near future.


Subject(s)
Antiviral Agents/pharmacology , Coronavirus 3C Proteases/antagonists & inhibitors , Cysteine Proteinase Inhibitors/pharmacology , Peptidomimetics/pharmacology , SARS Virus/drug effects , Animals , Antiviral Agents/chemical synthesis , Cell Line, Tumor , Cysteine Proteinase Inhibitors/chemical synthesis , Humans , Peptidomimetics/chemical synthesis , SARS Virus/enzymology , SARS-CoV-2/enzymology
SELECTION OF CITATIONS
SEARCH DETAIL