Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 24
Filter
1.
Pak J Biol Sci ; 26(2): 81-90, 2023 Jan.
Article in English | MEDLINE | ID: covidwho-20236999

ABSTRACT

<b>Background and Objective:</b> The COVID-19, which has been circulating since late 2019, is caused by SARS-CoV-2. Because of its high infectivity, this virus has spread widely throughout the world. Spike glycoprotein is one of the proteins found in SARS-CoV-2. Spike glycoproteins directly affect infection by forming ACE-2 receptors on host cells. Inhibiting glycoprotein spikes could be one method of treating COVID-19. In this study, the antivirus marketed as a database will be repurposed into an antiviral SARS-CoV-2 and the selected compounds will be modified to become organoselenium compounds. <b>Materials and Methods:</b> The research was carried out using <i>in silico</i> methods, such as rigid docking and flexible docking. To obtain information about the interaction between spike glycoprotein and ligands, MOE 2014.09 was used to perform the molecular docking simulation. <b>Results:</b> The analysis of binding energy values was used to select the ten best ligands from the first stage of the molecular docking simulation, which was then modified according to the previous QSAR study to produce 96 new molecules. The second stage of molecular docking simulation was performed with modified molecules. The best-modified ligand was chosen by analyzing the ADME-Tox property, RMSD value and binding energy value. <b>Conclusion:</b> The best three unmodified ligands, Ombitasvir, Elbasvir and Ledipasvir, have a binding energy value of -15.8065, -15.3842 and -15.1255 kcal mol<sup>1</sup>, respectively and the best three modified ligands ModL1, ModL2 and ModL3 has a binding value of -15.6716, -13.9489 and -13.2951 kcal mol<sup>1</sup>, respectively with an RMSD value of 1.7109 Å, 2.3179 Å and 1.7836 Å.


Subject(s)
COVID-19 , Organoselenium Compounds , Humans , SARS-CoV-2 , Ligands , Molecular Docking Simulation , Antiviral Agents/pharmacology , Molecular Dynamics Simulation
2.
Molecules ; 28(9)2023 Apr 26.
Article in English | MEDLINE | ID: covidwho-2318920

ABSTRACT

The antioxidant drug ebselen has been widely studied in both laboratories and in clinical trials. The catalytic mechanism by which it destroys hydrogen peroxide via reduction with glutathione or other thiols is complex and has been the subject of considerable debate. During reinvestigations of several key steps, we found that the seleninamide that comprises the first oxidation product of ebselen underwent facile reversible methanolysis to an unstable seleninate ester and two dimeric products. In its reaction with benzyl alcohol, the seleninamide produced a benzyl ester that reacted readily by selenoxide elimination, with formation of benzaldehyde. Oxidation of ebselen seleninic acid did not afford a selenonium seleninate salt as previously observed with benzene seleninic acid, but instead generated a mixture of the seleninic and selenonic acids. Thiolysis of ebselen with benzyl thiol was faster than oxidation by ca. an order of magnitude and produced a stable selenenyl sulfide. When glutathione was employed, the product rapidly disproportionated to glutathione disulfide and ebselen diselenide. Oxidation of the S-benzyl selenenyl sulfide, or thiolysis of the seleninamide with benzyl thiol, afforded a transient thiolseleninate that also readily underwent selenoxide elimination. The S-benzyl derivative disproportionated readily when catalyzed by the simultaneous presence of both the thiol and triethylamine. The phenylthio analogue disproportionated when exposed to ambient or UV (360 nm) light by a proposed radical mechanism. These observations provide additional insight into several reactions and intermediates related to ebselen.


Subject(s)
Antioxidants , Organoselenium Compounds , Glutathione Peroxidase/metabolism , Isoindoles , Oxidation-Reduction , Catalysis , Glutathione , Sulfides , Esters , Sulfhydryl Compounds , Azoles
3.
Int J Mol Sci ; 23(4)2022 Feb 21.
Article in English | MEDLINE | ID: covidwho-1703931

ABSTRACT

The review presents the latest data on the role of selenium-containing agents in the regulation of diseases of the immune system. We mainly considered the contributions of selenium-containing compounds such as sodium selenite, methylseleninic acid, selenomethionine, and methylselenocysteine, as well as selenoproteins and selenium nanoparticles in the regulation of defense mechanisms against various viral infections, including coronavirus infection (COVID-19). A complete description of the available data for each of the above selenium compounds and the mechanisms underlying the regulation of immune processes with the active participation of these selenium agents, as well as their therapeutic and pharmacological potential, is presented. The main purpose of this review is to systematize the available information, supplemented by data obtained in our laboratory, on the important role of selenium compounds in all of these processes. In addition, the presented information makes it possible to understand the key differences in the mechanisms of action of these compounds, depending on their chemical and physical properties, which is important for obtaining a holistic picture and prospects for creating drugs based on them.


Subject(s)
Antiviral Agents/pharmacology , COVID-19 Drug Treatment , Immunomodulating Agents/pharmacology , Selenium Compounds/pharmacology , Anti-Inflammatory Agents, Non-Steroidal/chemistry , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Antiviral Agents/chemistry , Humans , Immune System/drug effects , Immunomodulating Agents/chemistry , Organoselenium Compounds/immunology , Organoselenium Compounds/pharmacokinetics , Organoselenium Compounds/pharmacology , Selenium Compounds/immunology , Selenocysteine/analogs & derivatives , Selenocysteine/immunology , Selenocysteine/pharmacology , Selenomethionine/pharmacokinetics , Selenomethionine/pharmacology , Sodium Selenite/pharmacology
4.
Nucleic Acids Res ; 50(3): 1484-1500, 2022 02 22.
Article in English | MEDLINE | ID: covidwho-1624985

ABSTRACT

The SARS-CoV-2 coronavirus is the causal agent of the current global pandemic. SARS-CoV-2 belongs to an order, Nidovirales, with very large RNA genomes. It is proposed that the fidelity of coronavirus (CoV) genome replication is aided by an RNA nuclease complex, comprising the non-structural proteins 14 and 10 (nsp14-nsp10), an attractive target for antiviral inhibition. Our results validate reports that the SARS-CoV-2 nsp14-nsp10 complex has RNase activity. Detailed functional characterization reveals nsp14-nsp10 is a versatile nuclease capable of digesting a wide variety of RNA structures, including those with a blocked 3'-terminus. Consistent with a role in maintaining viral genome integrity during replication, we find that nsp14-nsp10 activity is enhanced by the viral RNA-dependent RNA polymerase complex (RdRp) consisting of nsp12-nsp7-nsp8 (nsp12-7-8) and demonstrate that this stimulation is mediated by nsp8. We propose that the role of nsp14-nsp10 in maintaining replication fidelity goes beyond classical proofreading by purging the nascent replicating RNA strand of a range of potentially replication-terminating aberrations. Using our developed assays, we identify drug and drug-like molecules that inhibit nsp14-nsp10, including the known SARS-CoV-2 major protease (Mpro) inhibitor ebselen and the HIV integrase inhibitor raltegravir, revealing the potential for multifunctional inhibitors in COVID-19 treatment.


Subject(s)
Antiviral Agents/pharmacology , Drug Evaluation, Preclinical , Exoribonucleases/metabolism , Genome, Viral/genetics , Genomic Instability , SARS-CoV-2/enzymology , SARS-CoV-2/genetics , Viral Nonstructural Proteins/metabolism , Viral Regulatory and Accessory Proteins/metabolism , Coronavirus RNA-Dependent RNA Polymerase/metabolism , Exoribonucleases/antagonists & inhibitors , Genome, Viral/drug effects , Genomic Instability/drug effects , Genomic Instability/genetics , HIV Integrase Inhibitors/pharmacology , Isoindoles/pharmacology , Multienzyme Complexes/antagonists & inhibitors , Multienzyme Complexes/metabolism , Organoselenium Compounds/pharmacology , RNA, Viral/biosynthesis , RNA, Viral/genetics , Raltegravir Potassium/pharmacology , SARS-CoV-2/drug effects , Viral Nonstructural Proteins/antagonists & inhibitors , Viral Regulatory and Accessory Proteins/antagonists & inhibitors , Virus Replication/drug effects , Virus Replication/genetics
5.
ChemMedChem ; 17(4): e202100582, 2022 02 16.
Article in English | MEDLINE | ID: covidwho-1540073

ABSTRACT

The reactive organoselenium compound ebselen is being investigated for treatment of coronavirus disease 2019 (COVID-19) and other diseases. We report structure-activity studies on sulfur analogues of ebselen with the Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) main protease (Mpro ), employing turnover and protein-observed mass spectrometry-based assays. The results reveal scope for optimisation of ebselen/ebselen derivative- mediated inhibition of Mpro , particularly with respect to improved selectivity.


Subject(s)
Coronavirus 3C Proteases/antagonists & inhibitors , Isoindoles/pharmacology , Organoselenium Compounds/pharmacology , Protease Inhibitors/pharmacology , SARS-CoV-2/enzymology , COVID-19/virology , Humans , Isoindoles/chemistry , Organoselenium Compounds/chemistry , Protease Inhibitors/chemistry , Structure-Activity Relationship
6.
Bioorg Chem ; 117: 105455, 2021 12.
Article in English | MEDLINE | ID: covidwho-1487613

ABSTRACT

The main protease (Mpro or 3CLpro) of SARS-CoV-2 virus is a cysteine enzyme critical for viral replication and transcription, thus indicating a potential target for antiviral therapy. A recent repurposing effort has identified ebselen, a multifunctional drug candidate as an inhibitor of Mpro. Our docking of ebselen to the binding pocket of Mpro crystal structure suggests a noncovalent interaction for improvement of potency, antiviral activity and selectivity. To test this hypothesis, we designed and synthesized ebselen derivatives aimed at enhancing their non-covalent bonds within Mpro. The inhibition of Mpro by ebselen derivatives (0.3 µM) was screened in both HPLC and FRET assays. Nine ebselen derivatives (EBs) exhibited stronger inhibitory effect on Mpro with IC50 of 0.07-0.38 µM. Further evaluation of three derivatives showed that EB2-7 exhibited the most potent inhibition of SARS-CoV-2 viral replication with an IC50 value of 4.08 µM in HPAepiC cells, as compared to the prototype ebselen at 24.61 µM. Mechanistically, EB2-7 functions as a noncovalent Mpro inhibitor in LC-MS/MS assay. Taken together, our identification of ebselen derivatives with improved antiviral activity may lead to developmental potential for treatment of COVID-19 and SARS-CoV-2 infection.


Subject(s)
Antiviral Agents/chemistry , Coronavirus 3C Proteases/chemistry , Isoindoles/chemistry , Organoselenium Compounds/chemistry , SARS-CoV-2/enzymology , Antiviral Agents/metabolism , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , Binding Sites , COVID-19/virology , Catalytic Domain , Cell Line , Cell Survival/drug effects , Chromatography, High Pressure Liquid , Coronavirus 3C Proteases/metabolism , Drug Design , Fluorescence Resonance Energy Transfer , Humans , Isoindoles/metabolism , Isoindoles/pharmacology , Isoindoles/therapeutic use , Molecular Docking Simulation , Organoselenium Compounds/metabolism , Organoselenium Compounds/pharmacology , Organoselenium Compounds/therapeutic use , SARS-CoV-2/isolation & purification , Structure-Activity Relationship , Tandem Mass Spectrometry , COVID-19 Drug Treatment
7.
Int J Mol Sci ; 22(18)2021 Sep 10.
Article in English | MEDLINE | ID: covidwho-1409705

ABSTRACT

The inhibition mechanism of the main protease (Mpro) of SARS-CoV-2 by ebselen (EBS) and its analog with a hydroxyl group at position 2 of the benzisoselenazol-3(2H)-one ring (EBS-OH) was studied by using a density functional level of theory. Preliminary molecular dynamics simulations on the apo form of Mpro were performed taking into account both the hydrogen donor and acceptor natures of the Nδ and Nε of His41, a member of the catalytic dyad. The potential energy surfaces for the formation of the Se-S covalent bond mediated by EBS and EBS-OH on Mpro are discussed in detail. The EBS-OH shows a distinctive behavior with respect to EBS in the formation of the noncovalent complex. Due to the presence of canonical H-bonds and noncanonical ones involving less electronegative atoms, such as sulfur and selenium, the influence on the energy barriers and reaction energy of the Minnesota hybrid meta-GGA functionals M06, M06-2X and M08HX, and the more recent range-separated hybrid functional wB97X were also considered. The knowledge of the inhibition mechanism of Mpro by the small protease inhibitors EBS or EBS-OH can enlarge the possibilities for designing more potent and selective inhibitor-based drugs to be used in combination with other antiviral therapies.


Subject(s)
Antiviral Agents/pharmacology , COVID-19 Drug Treatment , Coronavirus 3C Proteases/antagonists & inhibitors , Isoindoles/pharmacology , Organoselenium Compounds/pharmacology , Protease Inhibitors/pharmacology , Antiviral Agents/therapeutic use , Binding Sites/drug effects , COVID-19/virology , Catalytic Domain/drug effects , Coronavirus 3C Proteases/metabolism , Drug Design , Humans , Isoindoles/chemistry , Isoindoles/therapeutic use , Molecular Docking Simulation , Molecular Dynamics Simulation , Organoselenium Compounds/chemistry , Organoselenium Compounds/therapeutic use , Protease Inhibitors/chemistry , Protease Inhibitors/therapeutic use , SARS-CoV-2/drug effects , SARS-CoV-2/metabolism
8.
Nat Commun ; 12(1): 3061, 2021 05 24.
Article in English | MEDLINE | ID: covidwho-1387342

ABSTRACT

The SARS-CoV-2 pandemic has triggered global efforts to develop therapeutics. The main protease of SARS-CoV-2 (Mpro), critical for viral replication, is a key target for therapeutic development. An organoselenium drug called ebselen has been demonstrated to have potent Mpro inhibition and antiviral activity. We have examined the binding modes of ebselen and its derivative in Mpro via high resolution co-crystallography and investigated their chemical reactivity via mass spectrometry. Stronger Mpro inhibition than ebselen and potent ability to rescue infected cells were observed for a number of derivatives. A free selenium atom bound with cysteine of catalytic dyad has been revealed in crystallographic structures of Mpro with ebselen and MR6-31-2 suggesting hydrolysis of the enzyme bound organoselenium covalent adduct and formation of a phenolic by-product, confirmed by mass spectrometry. The target engagement with selenation mechanism of inhibition suggests wider therapeutic applications of these compounds against SARS-CoV-2 and other zoonotic beta-corona viruses.


Subject(s)
Azoles/pharmacology , Coronavirus 3C Proteases/antagonists & inhibitors , Organoselenium Compounds/pharmacology , SARS-CoV-2/enzymology , Antiviral Agents/pharmacology , Azoles/chemistry , Catalytic Domain , Coronavirus 3C Proteases/metabolism , Crystallography, X-Ray , Cysteine/chemistry , Hydrolysis , Isoindoles , Models, Molecular , Organoselenium Compounds/chemistry , Protease Inhibitors/chemistry , Protease Inhibitors/pharmacology , Reference Standards , SARS-CoV-2/drug effects , Salicylanilides/chemistry , Salicylanilides/pharmacology , Selenium/metabolism
9.
Arch Toxicol ; 95(4): 1179-1226, 2021 04.
Article in English | MEDLINE | ID: covidwho-1384375

ABSTRACT

Here, we addressed the pharmacology and toxicology of synthetic organoselenium compounds and some naturally occurring organoselenium amino acids. The use of selenium as a tool in organic synthesis and as a pharmacological agent goes back to the middle of the nineteenth and the beginning of the twentieth centuries. The rediscovery of ebselen and its investigation in clinical trials have motivated the search for new organoselenium molecules with pharmacological properties. Although ebselen and diselenides have some overlapping pharmacological properties, their molecular targets are not identical. However, they have similar anti-inflammatory and antioxidant activities, possibly, via activation of transcription factors, regulating the expression of antioxidant genes. In short, our knowledge about the pharmacological properties of simple organoselenium compounds is still elusive. However, contrary to our early expectations that they could imitate selenoproteins, organoselenium compounds seem to have non-specific modulatory activation of antioxidant pathways and specific inhibitory effects in some thiol-containing proteins. The thiol-oxidizing properties of organoselenium compounds are considered the molecular basis of their chronic toxicity; however, the acute use of organoselenium compounds as inhibitors of specific thiol-containing enzymes can be of therapeutic significance. In summary, the outcomes of the clinical trials of ebselen as a mimetic of lithium or as an inhibitor of SARS-CoV-2 proteases will be important to the field of organoselenium synthesis. The development of computational techniques that could predict rational modifications in the structure of organoselenium compounds to increase their specificity is required to construct a library of thiol-modifying agents with selectivity toward specific target proteins.


Subject(s)
Organoselenium Compounds/pharmacology , Organoselenium Compounds/toxicity , Amino Acids/chemistry , Animals , Azoles , Humans , Isoindoles , Molecular Structure , Selenium/chemistry , Selenium/physiology , Selenoproteins/chemistry , Sulfhydryl Compounds/chemistry
10.
Pharmacol Res Perspect ; 9(1): e00691, 2021 02.
Article in English | MEDLINE | ID: covidwho-1384293

ABSTRACT

Coronaviruses represent global health threat. In this century, they have already caused two epidemics and one serious pandemic. Although, at present, there are no approved drugs and therapies for the treatment and prevention of human coronaviruses, several agents, FDA-approved, and preclinical, have shown in vitro and/or in vivo antiviral activity. An in-depth analysis of the current situation leads to the identification of several potential drugs that could have an impact on the fight against coronaviruses infections. In this review, we discuss the virology of human coronaviruses highlighting the main biological targets and summarize the current state-of-the-art of possible therapeutic options to inhibit coronaviruses infections. We mostly focus on FDA-approved and preclinical drugs targeting viral conserved elements.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , COVID-19/metabolism , Coronavirus Infections/metabolism , Coronavirus/metabolism , Dipeptidyl Peptidase 4/metabolism , Severe Acute Respiratory Syndrome/metabolism , Angiotensin-Converting Enzyme 2/antagonists & inhibitors , Angiotensin-Converting Enzyme Inhibitors/administration & dosage , Angiotensin-Converting Enzyme Inhibitors/metabolism , Animals , Anti-Inflammatory Agents, Non-Steroidal/administration & dosage , Anti-Inflammatory Agents, Non-Steroidal/metabolism , Antiviral Agents/administration & dosage , Antiviral Agents/metabolism , Azoles/administration & dosage , Azoles/metabolism , Coronavirus/drug effects , Coronavirus Infections/drug therapy , Enzyme Inhibitors/administration & dosage , Enzyme Inhibitors/metabolism , Humans , Isoindoles , Naphthoquinones/administration & dosage , Naphthoquinones/metabolism , Organoselenium Compounds/administration & dosage , Organoselenium Compounds/metabolism , Severe Acute Respiratory Syndrome/drug therapy , COVID-19 Drug Treatment
13.
Environ Sci Technol ; 54(18): 11271-11281, 2020 09 15.
Article in English | MEDLINE | ID: covidwho-1373338

ABSTRACT

Ebselen (EBS), 2-phenyl-1,2-benzisoselenazol-3(2H)-one, is an organoselenium pharmaceutical with antioxidant and anti-inflammatory properties. Furthermore, EBS is an excellent scavenger of reactive oxygen species. This property complicates conventional protocols for sensitizing and quenching reactive species because of potential generation of active intermediates that quickly react with EBS. In this study, the photochemical reactivity of EBS was investigated in the presence of (1) 1O2 and •OH sensitizers [rose Bengal (RB), perinaphthanone, and H2O2] and (2) reactive species scavenging and quenching agents (sorbic acid, isopropanol, sodium azide, and tert-butanol) that are commonly employed to study photodegradation mechanisms and kinetics. The carbon analogue of EBS, namely, 2-phenyl-3H-isoindol-1-one, was included as a reference compound to confirm the impact of the selenium atom on EBS photochemical reactivity. EBS does not undergo acid dissociation, but pH-dependent kinetics were observed in RB-sensitized solutions, suggesting EBS reaction with active intermediates (3RB2-*, O2•-, and H2O2) that are not kinetically relevant for other compounds. In addition, the observed rate constant of EBS increased in the presence of sorbic acid, isopropanol, and sodium azide. These findings suggest that conventional reactive species sensitizers, scavengers, and quenchers need to be carefully applied to highly reactive organoselenium compounds to account for reactions that are typically slow for other organic contaminants.


Subject(s)
Hydrogen Peroxide , Organoselenium Compounds , Azoles , Isoindoles , Photolysis
14.
Mol Inform ; 40(8): e2100028, 2021 08.
Article in English | MEDLINE | ID: covidwho-1345038

ABSTRACT

The COVID-19 pandemic caused by the SARS-CoV-2 has mobilized scientific attention in search of a treatment. The cysteine-proteases, main protease (Mpro) and papain-like protease (PLpro) are important targets for antiviral drugs. In this work, we simulate the interactions between the Mpro and PLpro with Ebselen, its metabolites and derivatives with the aim of finding molecules that can potentially inhibit these enzymes. The docking data demonstrate that there are two main interactions between the thiol (-SH) group of Cys (from the protease active sites) and the electrophilic centers of the organoselenium molecules, i. e. the interaction with the carbonyl group (O=C… SH) and the interaction with the Se moiety (Se… SH). Both interactions may lead to an adduct formation and enzyme inhibition. Density Functional Theory (DFT) calculations with Ebselen indicate that the energetics of the thiol nucleophilic attack is more favorable on Se than on the carbonyl group, which is in accordance with experimental data (Jin et al. Nature, 2020, 582, 289-293). Therefore, organoselenium molecules should be further explored as inhibitors of the SARS-CoV-2 proteases. Furthermore, we suggest that some metabolites of Ebselen (e. g. Ebselen diselenide and methylebselenoxide) and derivatives ethaselen and ebsulfur should be tested in vitro as inhibitors of virus replication and its proteases.


Subject(s)
Azoles/pharmacology , COVID-19 Drug Treatment , Coronavirus Papain-Like Proteases/metabolism , Organoselenium Compounds/pharmacology , Protease Inhibitors/pharmacology , SARS-CoV-2/drug effects , Viral Matrix Proteins/metabolism , Antiviral Agents/chemistry , Antiviral Agents/metabolism , Antiviral Agents/pharmacology , Azoles/chemistry , Azoles/metabolism , COVID-19/metabolism , Catalytic Domain/drug effects , Coronavirus Papain-Like Proteases/antagonists & inhibitors , Drug Discovery , Humans , Isoindoles , Molecular Docking Simulation , Organoselenium Compounds/chemistry , Organoselenium Compounds/metabolism , Protease Inhibitors/chemistry , Protease Inhibitors/metabolism , Viral Matrix Proteins/antagonists & inhibitors
15.
Molecules ; 26(14)2021 Jul 12.
Article in English | MEDLINE | ID: covidwho-1323315

ABSTRACT

Ebselen is the leader of selenorganic compounds, and starting from its identification as mimetic of the key antioxidant enzyme glutathione peroxidase, several papers have appeared in literature claiming its biological activities. It was the subject of several clinical trials and it is currently in clinical evaluation for the treatment of COVID-19 patients. Given our interest in the synthesis and pharmacological evaluation of selenorganic derivatives with this review, we aimed to collect all the papers focused on the biological evaluation of ebselen and its close analogues, covering the timeline between 2016 and most of 2021. Our analysis evidences that, even if it lacks specificity when tested in vitro, being able to bind to every reactive cysteine, it proved to be always well tolerated in vivo, exerting no sign of toxicity whatever the administered doses. Besides, looking at the literature, we realized that no review article dealing with the synthetic approaches for the construction of the benzo[d][1,2]-selenazol-3(2H)-one scaffold is available; thus, a section of the present review article is completely devoted to this specific topic.


Subject(s)
Azoles/chemistry , Azoles/chemical synthesis , Azoles/pharmacology , Organoselenium Compounds/chemistry , Organoselenium Compounds/chemical synthesis , Organoselenium Compounds/pharmacology , Animals , Anti-Infective Agents/pharmacology , Antioxidants/pharmacology , Antiviral Agents/pharmacology , Biomimetics/methods , Cyclooxygenase Inhibitors/pharmacology , Glutathione Peroxidase/metabolism , Glutathione Peroxidase/pharmacology , Humans , Isoindoles , Molecular Structure , Neuroprotective Agents/pharmacology , Selenium/chemistry , Selenoproteins/chemical synthesis , Selenoproteins/pharmacology
16.
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 , Isoindoles , 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
17.
Mol Pharmacol ; 100(2): 155-169, 2021 08.
Article in English | MEDLINE | ID: covidwho-1242189

ABSTRACT

The 14-3-3 proteins constitute a family of adaptor proteins with many binding partners and biological functions, and they are considered promising drug targets in cancer and neuropsychiatry. By screening 1280 small-molecule drugs using differential scanning fluorimetry (DSF), we found 15 compounds that decreased the thermal stability of 14-3-3ζ Among these compounds, ebselen was identified as a covalent, destabilizing ligand of 14-3-3 isoforms ζ, ε, γ, and η Ebselen bonding decreased 14-3-3ζ binding to its partner Ser19-phosphorylated tyrosine hydroxylase. Characterization of site-directed mutants at cysteine residues in 14-3-3ζ (C25, C94, and C189) by DSF and mass spectroscopy revealed covalent modification by ebselen of all cysteines through a selenylsulfide bond. C25 appeared to be the preferential site of ebselen interaction in vitro, whereas modification of C94 was the main determinant for protein destabilization. At therapeutically relevant concentrations, ebselen and ebselen oxide caused decreased 14-3-3 levels in SH-SY5Y cells, accompanied with an increased degradation, most probably by the ubiquitin-dependent proteasome pathway. Moreover, ebselen-treated zebrafish displayed decreased brain 14-3-3 content, a freezing phenotype, and reduced mobility, resembling the effects of lithium, consistent with its proposed action as a safer lithium-mimetic drug. Ebselen has recently emerged as a promising drug candidate in several medical areas, such as cancer, neuropsychiatric disorders, and infectious diseases, including coronavirus disease 2019. Its pleiotropic actions are attributed to antioxidant effects and formation of selenosulfides with critical cysteine residues in proteins. Our work indicates that a destabilization of 14-3-3 may affect the protein interaction networks of this protein family, contributing to the therapeutic potential of ebselen. SIGNIFICANCE STATEMENT: There is currently great interest in the repurposing of established drugs for new indications and therapeutic targets. This study shows that ebselen, which is a promising drug candidate against cancer, bipolar disorder, and the viral infection coronavirus disease 2019, covalently bonds to cysteine residues in 14-3-3 adaptor proteins, triggering destabilization and increased degradation in cells and intact brain tissue when used in therapeutic concentrations, potentially explaining the behavioral, anti-inflammatory, and antineoplastic effects of this drug.


Subject(s)
14-3-3 Proteins/chemistry , 14-3-3 Proteins/metabolism , Cysteine/genetics , Isoindoles/pharmacology , Organoselenium Compounds/pharmacology , 14-3-3 Proteins/genetics , Animals , Binding Sites/drug effects , Brain/metabolism , Cell Line , Circular Dichroism , Down-Regulation , Female , Humans , Male , Models, Molecular , Mutagenesis, Site-Directed , Protein Binding/drug effects , Protein Conformation , Protein Stability/drug effects , Tyrosine 3-Monooxygenase/metabolism , Zebrafish , Zebrafish Proteins/chemistry , Zebrafish Proteins/metabolism
18.
Sci Rep ; 11(1): 3640, 2021 02 11.
Article in English | MEDLINE | ID: covidwho-1078609

ABSTRACT

An efficient treatment against a COVID-19 disease, caused by the novel coronavirus SARS-CoV-2 (CoV2), remains a challenge. The papain-like protease (PLpro) from the human coronavirus is a protease that plays a critical role in virus replication. Moreover, CoV2 uses this enzyme to modulate the host's immune system to its own benefit. Therefore, it represents a highly promising target for the development of antiviral drugs. We used Approximate Bayesian Computation tools, molecular modelling and enzyme activity studies to identify highly active inhibitors of the PLpro. We discovered organoselenium compounds, ebselen and its structural analogues, as a novel approach for inhibiting the activity of PLproCoV2. Furthermore, we identified, for the first time, inhibitors of PLproCoV2 showing potency in the nanomolar range. Moreover, we found a difference between PLpro from SARS and CoV2 that can be correlated with the diverse dynamics of their replication, and, putatively to disease progression.


Subject(s)
Antiviral Agents/pharmacology , Azoles/pharmacology , Coronavirus Papain-Like Proteases/antagonists & inhibitors , Molecular Docking Simulation , Organoselenium Compounds/pharmacology , Protease Inhibitors/pharmacology , Antiviral Agents/chemistry , Azoles/chemistry , Binding Sites , Coronavirus Papain-Like Proteases/chemistry , Coronavirus Papain-Like Proteases/metabolism , Isoindoles , Organoselenium Compounds/chemistry , Protease Inhibitors/chemistry , Protein Binding
19.
Sci Adv ; 6(37)2020 09.
Article in English | MEDLINE | ID: covidwho-760208

ABSTRACT

There is an urgent need to repurpose drugs against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Recent computational-experimental screenings have identified several existing drugs that could serve as effective inhibitors of the virus' main protease, Mpro, which is involved in gene expression and replication. Among these, ebselen (2-phenyl-1,2-benzoselenazol-3-one) appears to be particularly promising. Here, we examine, at a molecular level, the potential of ebselen to decrease Mpro activity. We find that it exhibits a distinct affinity for the catalytic region. Our results reveal a higher-affinity, previously unknown binding site localized between the II and III domains of the protein. A detailed strain analysis indicates that, on such a site, ebselen exerts a pronounced allosteric effect that regulates catalytic site access through surface-loop interactions, thereby inducing a reconfiguration of water hotspots. Together, these findings highlight the promise of ebselen as a repurposed drug against SARS-CoV-2.


Subject(s)
Antiviral Agents/pharmacology , Azoles/metabolism , Azoles/pharmacology , Betacoronavirus/drug effects , Coronavirus Infections/drug therapy , Cysteine Endopeptidases/metabolism , Organoselenium Compounds/metabolism , Organoselenium Compounds/pharmacology , Pneumonia, Viral/drug therapy , Viral Nonstructural Proteins/metabolism , Antiviral Agents/metabolism , Betacoronavirus/metabolism , Binding Sites , COVID-19 , Catalytic Domain/drug effects , Coronavirus 3C Proteases , Drug Repositioning , Humans , Isoindoles , Models, Molecular , Molecular Dynamics Simulation , Pandemics , Protein Conformation/drug effects , SARS-CoV-2
20.
Redox Biol ; 37: 101715, 2020 10.
Article in English | MEDLINE | ID: covidwho-752931

ABSTRACT

Selenium is a trace element essential to human health largely because of its incorporation into selenoproteins that have a wide range of protective functions. Selenium has an ongoing history of reducing the incidence and severity of various viral infections; for example, a German study found selenium status to be significantly higher in serum samples from surviving than non-surviving COVID-19 patients. Furthermore, a significant, positive, linear association was found between the cure rate of Chinese patients with COVID-19 and regional selenium status. Moreover, the cure rate continued to rise beyond the selenium intake required to optimise selenoproteins, suggesting that selenoproteins are probably not the whole story. Nonetheless, the significantly reduced expression of a number of selenoproteins, including those involved in controlling ER stress, along with increased expression of IL-6 in SARS-CoV-2 infected cells in culture suggests a potential link between reduced selenoprotein expression and COVID-19-associated inflammation. In this comprehensive review, we describe the history of selenium in viral infections and then go on to assess the potential benefits of adequate and even supra-nutritional selenium status. We discuss the indispensable function of the selenoproteins in coordinating a successful immune response and follow by reviewing cytokine excess, a key mediator of morbidity and mortality in COVID-19, and its relationship to selenium status. We comment on the fact that the synthetic redox-active selenium compound, ebselen, has been found experimentally to be a strong inhibitor of the main SARS-CoV-2 protease that enables viral maturation within the host. That finding suggests that redox-active selenium species formed at high selenium intake might hypothetically inhibit SARS-CoV-2 proteases. We consider the tactics that SARS-CoV-2 could employ to evade an adequate host response by interfering with the human selenoprotein system. Recognition of the myriad mechanisms by which selenium might potentially benefit COVID-19 patients provides a rationale for randomised, controlled trials of selenium supplementation in SARS-CoV-2 infection.


Subject(s)
COVID-19/immunology , Inflammation/immunology , Selenium/immunology , Selenoproteins/immunology , Animals , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Azoles/pharmacology , Azoles/therapeutic use , Coronavirus 3C Proteases/antagonists & inhibitors , Coronavirus 3C Proteases/immunology , Cytokines/immunology , Humans , Inflammation/drug therapy , Isoindoles , Organoselenium Compounds/pharmacology , Organoselenium Compounds/therapeutic use , SARS-CoV-2/immunology , SARS-CoV-2/physiology , Viral Protease Inhibitors/pharmacology , Viral Protease Inhibitors/therapeutic use , COVID-19 Drug Treatment
SELECTION OF CITATIONS
SEARCH DETAIL