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1.
Int J Mol Sci ; 23(4)2022 Feb 11.
Article in English | MEDLINE | ID: covidwho-1715396

ABSTRACT

Interferon-ß (IFN-ß) is a pleiotropic cytokine secreted in response to various pathological conditions and is clinically used for therapy of multiple sclerosis. Its application for treatment of cancer, infections and pulmonary diseases is limited by incomplete understanding of regulatory mechanisms of its functioning. Recently, we reported that IFN-ß activity is affected by interactions with S100A1, S100A4, S100A6, and S100P proteins, which are members of the S100 protein family of multifunctional Ca2+-binding proteins possessing cytokine-like activities (Int J Mol Sci. 2020;21(24):9473). Here we show that IFN-ß interacts with one more representative of the S100 protein family, the S100B protein, involved in numerous oncological and neurological diseases. The use of chemical crosslinking, intrinsic fluorescence, and surface plasmon resonance spectroscopy revealed IFN-ß binding to Ca2+-loaded dimeric and monomeric forms of the S100B protein. Calcium depletion blocks the S100B-IFN-ß interaction. S100B monomerization increases its affinity to IFN-ß by 2.7 orders of magnitude (equilibrium dissociation constant of the complex reaches 47 pM). Crystal violet assay demonstrated that combined application of IFN-ß and S100B (5-25 nM) eliminates their inhibitory effects on MCF-7 cell viability. Bioinformatics analysis showed that the direct modulation of IFN-ß activity by the S100B protein described here could be relevant to progression of multiple oncological and neurological diseases.


Subject(s)
Interferon-beta/metabolism , S100 Calcium Binding Protein beta Subunit/metabolism , Animals , CHO Cells , Calcium/metabolism , Cell Line, Tumor , Cricetulus , Humans , MCF-7 Cells , Nervous System Diseases/metabolism , Protein Binding/physiology
2.
Biomed Pharmacother ; 148: 112756, 2022 Apr.
Article in English | MEDLINE | ID: covidwho-1708753

ABSTRACT

The 2019 corona virus disease (COVID-19) has caused a global chaos, where a novel Omicron variant has challenged the healthcare system, followed by which it has been referred to as a variant of concern (VOC) by the World Health Organization (WHO), owing to its alarming transmission and infectivity rate. The large number of mutations in the receptor binding domain (RBD) of the spike protein is responsible for strengthening of the spike-angiotensin-converting enzyme 2 (ACE2) interaction, thereby explaining the elevated threat. This is supplemented by enhanced resistance of the variant towards pre-existing antibodies approved for the COVID-19 therapy. The manuscript brings into light failure of existing therapies to provide the desired effect, however simultaneously discussing the novel possibilities on the verge of establishing suitable treatment portfolio. The authors entail the risks associated with omicron resistance against antibodies and vaccine ineffectiveness on one side, and novel approaches and targets - kinase inhibitors, viral protease inhibitors, phytoconstituents, entry pathways - on the other. The manuscript aims to provide a holistic picture about the Omicron variant, by providing comprehensive discussions related to multiple aspects of the mutated spike variant, which might aid the global researchers and healthcare experts in finding an optimised solution to this pandemic.


Subject(s)
COVID-19/physiopathology , SARS-CoV-2/genetics , SARS-CoV-2/metabolism , Angiotensin-Converting Enzyme 2/metabolism , Animals , COVID-19/immunology , COVID-19 Vaccines/immunology , Cathepsins/metabolism , ErbB Receptors/antagonists & inhibitors , Humans , Immunization Schedule , Immunization, Secondary , Phytotherapy/methods , Plants, Medicinal , Protein Binding/physiology , Protein Interaction Domains and Motifs/physiology , Protein Structural Elements/physiology , Spike Glycoprotein, Coronavirus/metabolism , Viral Protease Inhibitors/pharmacology , Viral Protease Inhibitors/therapeutic use
3.
Biochim Biophys Acta Mol Basis Dis ; 1868(3): 166322, 2022 03 01.
Article in English | MEDLINE | ID: covidwho-1637812

ABSTRACT

BACKGROUND: Acute kidney injury (AKI) is both a consequence and determinant of outcomes in COVID-19. The kidney is one of the major organs infected by the causative virus, SARS-CoV-2. Viral entry into cells requires the viral spike protein, and both the virus and its spike protein appear in the urine of COVID-19 patients with AKI. We examined the effects of transfecting the viral spike protein of SARS-CoV-2 in kidney cell lines. METHODS: HEK293, HEK293-ACE2+ (stably overexpressing ACE2), and Vero E6 cells having endogenous ACE2 were transfected with SARS-CoV-2 spike or control plasmid. Assessment of gene and protein expression, and syncytia formation was performed, and the effects of quercetin on syncytia formation examined. FINDINGS: Spike transfection in HEK293-ACE2+ cells caused syncytia formation, cellular sloughing, and focal denudation of the cell monolayer; transfection in Vero E6 cells also caused syncytia formation. Spike expression upregulated potentially nephrotoxic genes (TNF-α, MCP-1, and ICAM1). Spike upregulated the cytoprotective gene HO-1 and relevant signaling pathways (p-Akt, p-STAT3, and p-p38). Quercetin, an HO-1 inducer, reduced syncytia formation and spike protein expression. INTERPRETATION: The major conclusions of the study are: 1) Spike protein expression in kidney cells provides a relevant model for the study of maladaptive and adaptive responses germane to AKI in COVID-19; 2) such spike protein expression upregulates HO-1; and 3) quercetin, an HO-1 inducer, may provide a clinically relevant/feasible protective strategy in AKI occurring in the setting of COVID-19. FUNDING: R01-DK119167 (KAN), R01-AI100911 (JPG), P30-DK079337; R01-DK059600 (AA).


Subject(s)
COVID-19/metabolism , Heme Oxygenase-1/metabolism , SARS-CoV-2/pathogenicity , Spike Glycoprotein, Coronavirus/metabolism , Animals , COVID-19/virology , Cell Line , Chlorocebus aethiops , HEK293 Cells , Host-Pathogen Interactions/drug effects , Host-Pathogen Interactions/physiology , Humans , Protein Binding/drug effects , Protein Binding/physiology , Quercetin/pharmacology , Signal Transduction/drug effects , Signal Transduction/physiology , Up-Regulation/drug effects , Up-Regulation/physiology , Vero Cells , Virus Internalization/drug effects
4.
Biomed Pharmacother ; 146: 112513, 2022 Feb.
Article in English | MEDLINE | ID: covidwho-1575252

ABSTRACT

The interactions of four sulfonylated Phe(3-Am)-derived inhibitors (MI-432, MI-463, MI-482 and MI-1900) of type II transmembrane serine proteases (TTSP) such as transmembrane protease serine 2 (TMPRSS2) were examined with serum albumin and cytochrome P450 (CYP) isoenzymes. Complex formation with albumin was investigated using fluorescence spectroscopy. Furthermore, microsomal hepatic CYP1A2, 2C9, 2C19 and 3A4 activities in presence of these inhibitors were determined using fluorometric assays. The inhibitory effects of these compounds on human recombinant CYP3A4 enzyme were also examined. In addition, microsomal stability assays (60-min long) were performed using an UPLC-MS/MS method to determine depletion percentage values of each compound. The inhibitors showed no or only weak interactions with albumin, and did not inhibit CYP1A2, 2C9 and 2C19. However, the compounds tested proved to be potent inhibitors of CYP3A4 in both assays performed. Within one hour, 20%, 12%, 14% and 25% of inhibitors MI-432, MI-463, MI-482 and MI-1900, respectively, were degraded. As essential host cell factor for the replication of the pandemic SARS-CoV-2, the TTSP TMPRSS2 emerged as an important target in drug design. Our study provides further preclinical data on the characterization of this type of inhibitors for numerous trypsin-like serine proteases.


Subject(s)
Antiviral Agents/metabolism , Cytochrome P-450 Enzyme System/metabolism , Protease Inhibitors/metabolism , Serine Endopeptidases/metabolism , Serum Albumin, Human/metabolism , Antiviral Agents/analysis , Antiviral Agents/pharmacology , Dose-Response Relationship, Drug , Humans , Isoenzymes/metabolism , Microsomes, Liver/drug effects , Microsomes, Liver/metabolism , Protease Inhibitors/analysis , Protease Inhibitors/pharmacology , Protein Binding/physiology , Serine Endopeptidases/analysis , Spectrometry, Fluorescence/methods , Tandem Mass Spectrometry/methods
5.
STAR Protoc ; 3(1): 101024, 2022 03 18.
Article in English | MEDLINE | ID: covidwho-1525990

ABSTRACT

The SARS-CoV-2 coronavirus infects human cells through the interaction of the viral envelope spike protein (IPR044366) with the human angiotensin-converting enzyme 2 (ACE2), expressed at the surface of target cells. Here, we describe a detailed protocol to measure the binding of the receptor binding domain (RBD) of spike to ACE2 by time-resolved fluorescence resonance energy transfer (TR-FRET). The assay detects the spike/ACE2 interaction in physiologically relevant cellular contexts and is suitable for high-throughput investigation of interfering small-molecule compounds and antibodies. For complete details on the use and execution of this protocol, please refer to Cecon et al. (2021).


Subject(s)
Fluorescence Resonance Energy Transfer/methods , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/metabolism , Angiotensin-Converting Enzyme 2/metabolism , COVID-19/immunology , COVID-19/metabolism , HEK293 Cells , Humans , Protein Binding/physiology , SARS-CoV-2/pathogenicity , Spike Glycoprotein, Coronavirus/immunology
6.
CPT Pharmacometrics Syst Pharmacol ; 10(12): 1497-1511, 2021 12.
Article in English | MEDLINE | ID: covidwho-1449945

ABSTRACT

This study aimed to determine whether published pharmacokinetic (PK) models can adequately predict the PK profile of imatinib in a new indication, such as coronavirus disease 2019 (COVID-19). Total (bound + unbound) and unbound imatinib plasma concentrations obtained from 134 patients with COVID-19 participating in the CounterCovid study and from an historical dataset of 20 patients with gastrointestinal stromal tumor (GIST) and 85 patients with chronic myeloid leukemia (CML) were compared. Total imatinib area under the concentration time curve (AUC), maximum concentration (Cmax ) and trough concentration (Ctrough ) were 2.32-fold (95% confidence interval [CI] 1.34-3.29), 2.31-fold (95% CI 1.33-3.29), and 2.32-fold (95% CI 1.11-3.53) lower, respectively, for patients with CML/GIST compared with patients with COVID-19, whereas unbound concentrations were comparable among groups. Inclusion of alpha1-acid glycoprotein (AAG) concentrations measured in patients with COVID-19 into a previously published model developed to predict free imatinib concentrations in patients with GIST using total imatinib and plasma AAG concentration measurements (AAG-PK-Model) gave an estimated mean (SD) prediction error (PE) of -20% (31%) for total and -7.0% (56%) for unbound concentrations. Further covariate modeling with this combined dataset showed that in addition to AAG; age, bodyweight, albumin, CRP, and intensive care unit admission were predictive of total imatinib oral clearance. In conclusion, high total and unaltered unbound concentrations of imatinib in COVID-19 compared to CML/GIST were a result of variability in acute phase proteins. This is a textbook example of how failure to take into account differences in plasma protein binding and the unbound fraction when interpreting PK of highly protein bound drugs, such as imatinib, could lead to selection of a dose with suboptimal efficacy in patients with COVID-19.


Subject(s)
Acute-Phase Proteins/metabolism , COVID-19/blood , COVID-19/drug therapy , Imatinib Mesylate/blood , Protein Kinase Inhibitors/blood , Aged , Aged, 80 and over , Female , Humans , Imatinib Mesylate/therapeutic use , Male , Middle Aged , Protein Binding/drug effects , Protein Binding/physiology , Protein Kinase Inhibitors/therapeutic use
7.
Viruses ; 13(10)2021 09 30.
Article in English | MEDLINE | ID: covidwho-1444332

ABSTRACT

Several vaccines with varying efficacies have been developed and are currently administered globally to minimize the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Despite having an RNA-dependent RNA polymerase with a proofreading activity, new variants of SARS-CoV-2 are on the rise periodically. Some of the mutations in these variants, especially mutations on the spike protein, aid the virus in transmission, infectivity and host immune evasion. Further, these mutations also reduce the effectiveness of some of the current vaccines and monoclonal antibodies (mAbs). In the present study, using the available 984,769 SARS-CoV-2 nucleotide sequences on the NCBI database from the end of 2019 till 28 July 2021, we have estimated the global prevalence of so-called 'adaptive mutations' and 'mutations identified in the prolonged infections', in the receptor-binding domain (RBD) of the spike (S) protein. Irrespective of the geographical region, in the case of the adaptive mutations, N501Y (48.38%) was found to be the dominant mutation followed by L452R (17.52%), T478K (14.31%), E484K (4.69%), S477N (3.29%), K417T (1.64%), N439K (0.7%) and S494P (0.7%). Other mutations were found to be less prevalent (less than 0.7%). Since the last two months, there has been a massive increase of L452R and T478K mutations (delta variant) in certain areas. In the case of prolonged infections' mutations (long-term SARS-CoV-2 infections), V483A (0.009%) was found to be dominant followed by Q493R (0.009%), while other mutations were found in less than 0.007% of the studied sequences. The data obtained in this study will aid in the development of better infection control policies, thereby curbing the spread of this virus.


Subject(s)
COVID-19/metabolism , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics , Adaptation, Biological/genetics , Antibodies, Neutralizing/immunology , COVID-19/genetics , COVID-19/immunology , Databases, Genetic , Humans , Immune Evasion/genetics , Mutation/genetics , Prevalence , Protein Binding/physiology , Protein Domains/genetics , SARS-CoV-2/immunology , SARS-CoV-2/metabolism , SARS-CoV-2/pathogenicity , Spike Glycoprotein, Coronavirus/metabolism
8.
Biochemistry ; 60(40): 2978-2986, 2021 10 12.
Article in English | MEDLINE | ID: covidwho-1440443

ABSTRACT

The SARS-CoV-2 spike protein is the primary antigenic determinant of the virus and has been studied extensively, yet the process of membrane fusion remains poorly understood. The fusion domain (FD) of viral glycoproteins is well established as facilitating the initiation of membrane fusion. An improved understanding of the structural plasticity associated with these highly conserved regions aids in our knowledge of the molecular mechanisms that drive viral fusion. Within the spike protein, the FD of SARS-CoV-2 exists immediately following S2' cleavage at the N-terminus of the S2 domain. Here we have shown that following the introduction of a membrane at pH 7.4, the FD undergoes a transition from a random coil to a more structurally well-defined postfusion state. Furthermore, we have classified the domain into two distinct regions, a fusion peptide (FP, S816-G838) and a fusion loop (FL, D839-F855). The FP forms a helix-turn-helix motif upon association with a membrane, and the favorable entropy gained during this transition from a random coil is likely the driving force behind membrane insertion. Membrane depth experiments then revealed the FP is found inserted within the membrane below the lipid headgroups, while the interaction of the FL with the membrane is shallower in nature. Thus, we propose a structural model relevant to fusion at the plasma membrane in which the FP inserts itself just below the phospholipid headgroups and the FL lays upon the lipid membrane surface.


Subject(s)
Cell Membrane/metabolism , Membrane Fusion/physiology , Models, Biological , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/metabolism , Amino Acid Sequence , COVID-19/genetics , COVID-19/metabolism , Cell Membrane/genetics , Humans , Protein Binding/physiology , SARS-CoV-2/chemistry , SARS-CoV-2/genetics , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/genetics
9.
Cell Rep ; 37(2): 109822, 2021 10 12.
Article in English | MEDLINE | ID: covidwho-1433046

ABSTRACT

Potent neutralizing monoclonal antibodies are one of the few agents currently available to treat COVID-19. SARS-CoV-2 variants of concern (VOCs) that carry multiple mutations in the viral spike protein can exhibit neutralization resistance, potentially affecting the effectiveness of some antibody-based therapeutics. Here, the generation of a diverse panel of 91 human, neutralizing monoclonal antibodies provides an in-depth structural and phenotypic definition of receptor binding domain (RBD) antigenic sites on the viral spike. These RBD antibodies ameliorate SARS-CoV-2 infection in mice and hamster models in a dose-dependent manner and in proportion to in vitro, neutralizing potency. Assessing the effect of mutations in the spike protein on antibody recognition and neutralization highlights both potent single antibodies and stereotypic classes of antibodies that are unaffected by currently circulating VOCs, such as B.1.351 and P.1. These neutralizing monoclonal antibodies and others that bind analogous epitopes represent potentially useful future anti-SARS-CoV-2 therapeutics.


Subject(s)
Angiotensin-Converting Enzyme 2/immunology , Antibodies, Neutralizing/immunology , SARS-CoV-2/immunology , Angiotensin-Converting Enzyme 2/metabolism , Angiotensin-Converting Enzyme 2/ultrastructure , Animals , Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/therapeutic use , Antibodies, Neutralizing/ultrastructure , Antibodies, Viral/immunology , COVID-19/immunology , Cricetinae , Cryoelectron Microscopy/methods , Epitopes/immunology , Female , Humans , Male , Mice , Mice, Inbred C57BL , Middle Aged , Neutralization Tests , Protein Binding/physiology , Receptors, Virus/metabolism , SARS-CoV-2/pathogenicity , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology
10.
Mol Pharmacol ; 100(6): 548-557, 2021 12.
Article in English | MEDLINE | ID: covidwho-1403004

ABSTRACT

Equilibrative nucleoside transporters (ENTs) are present at the blood-testis barrier (BTB), where they can facilitate antiviral drug disposition to eliminate a sanctuary site for viruses detectable in semen. The purpose of this study was to investigate ENT-drug interactions with three nucleoside analogs, remdesivir, molnupiravir, and molnupiravir's active metabolite, ß-d-N4-hydroxycytidine (EIDD-1931), and four non-nucleoside molecules repurposed as antivirals for coronavirus disease 2019 (COVID-19). The study used three-dimensional pharmacophores for ENT1 and ENT2 substrates and inhibitors and Bayesian machine learning models to identify potential interactions with these transporters. In vitro transport experiments demonstrated that remdesivir was the most potent inhibitor of ENT-mediated [3H]uridine uptake (ENT1 IC50: 39 µM; ENT2 IC50: 77 µM), followed by EIDD-1931 (ENT1 IC50: 259 µM; ENT2 IC50: 467 µM), whereas molnupiravir was a modest inhibitor (ENT1 IC50: 701 µM; ENT2 IC50: 851 µM). Other proposed antivirals failed to inhibit ENT-mediated [3H]uridine uptake below 1 mM. Remdesivir accumulation decreased in the presence of 6-S-[(4-nitrophenyl)methyl]-6-thioinosine (NBMPR) by 30% in ENT1 cells (P = 0.0248) and 27% in ENT2 cells (P = 0.0054). EIDD-1931 accumulation decreased in the presence of NBMPR by 77% in ENT1 cells (P = 0.0463) and by 64% in ENT2 cells (P = 0.0132), which supported computational predictions that both are ENT substrates that may be important for efficacy against COVID-19. NBMPR failed to decrease molnupiravir uptake, suggesting that ENT interaction is likely inhibitory. Our combined computational and in vitro data can be used to identify additional ENT-drug interactions to improve our understanding of drugs that can circumvent the BTB. SIGNIFICANCE STATEMENT: This study identified remdesivir and EIDD-1931 as substrates of equilibrative nucleoside transporters 1 and 2. This provides a potential mechanism for uptake of these drugs into cells and may be important for antiviral potential in the testes and other tissues expressing these transporters.


Subject(s)
Adenosine Monophosphate/analogs & derivatives , Alanine/analogs & derivatives , Antiviral Agents/metabolism , Cytidine/analogs & derivatives , Equilibrative Nucleoside Transporter 1/metabolism , Equilibrative-Nucleoside Transporter 2/metabolism , SARS-CoV-2/metabolism , Adenosine Monophosphate/administration & dosage , Adenosine Monophosphate/metabolism , Alanine/administration & dosage , Alanine/metabolism , Antiviral Agents/administration & dosage , COVID-19/drug therapy , COVID-19/metabolism , Cytidine/administration & dosage , Cytidine/metabolism , Dose-Response Relationship, Drug , Drug Interactions/physiology , HeLa Cells , Humans , Protein Binding/drug effects , Protein Binding/physiology , SARS-CoV-2/drug effects
11.
Arch Pharm (Weinheim) ; 354(11): e2100160, 2021 Nov.
Article in English | MEDLINE | ID: covidwho-1370365

ABSTRACT

Boswellic acids (BAs) have been shown to possess antiviral activity. Using bioinformatic methods, it was tested whether or not acetyl-11-keto-ß-boswellic acid (AKBA), 11-keto-ß-boswellic acid (KBA), ß-boswellic acid (BBA), and the phosphorylated active metabolite of Remdesivir® (RGS-P3) bind to functional proteins of SARS-CoV-2, that is, the replicase polyprotein P0DTD1, the spike glycoprotein P0DTC2, and the nucleoprotein P0DTC9. Using P0DTD1, AKBA and KBA showed micromolar binding affinity to the RNA-dependent RNA polymerase (RdRp) and to the main proteinase complex Mpro . Phosphorylated BAs even bond in the nanomolar range. Due to their positive and negative charges, BAs and RGS-P3 bond to corresponding negative and positive areas of the protein. BAs and RGS-P3 docked in the tunnel-like cavity of RdRp. BAs also docked into the elongated surface rim of viral Mpro . In both cases, binding occurred with active site amino acids in the lower micromolecular to upper nanomolar range. KBA, BBA, and RGS-P3 also bond to P0DTC2 and P0DTC9. The binding energies for BAs were in the range of -5.8 to -6.3 kcal/mol. RGS-P3 and BAs occluded the centrally located pore of the donut-like protein structure of P0DTC9 and, in the case of P0DTC2, RGS-P3 and BAs impacted the double-wing-like protein structure. The data of this bioinformatics study clearly show that BAs bind to three functional proteins of the SARS-CoV-2 virus responsible for adhesion and replication, as does RGS-P3, a drug on the market to treat this disease. The binding effectiveness of BAs can be increased through phosphate esterification. Whether or not BAs are druggable against the SARS-CoV-2 disease remains to be established.


Subject(s)
Adenosine Monophosphate/analogs & derivatives , Alanine/analogs & derivatives , COVID-19 , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/physiology , Triterpenes/pharmacology , Viral Proteins/physiology , Adenosine Monophosphate/pharmacology , Alanine/pharmacology , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Antiviral Agents/pharmacology , Binding Sites/physiology , Boswellia , COVID-19/drug therapy , COVID-19/virology , Computational Biology/methods , Humans , Molecular Docking Simulation , Nucleoproteins/metabolism , Polyproteins/metabolism , Prodrugs/pharmacology , Protein Binding/physiology , SARS-CoV-2/drug effects , SARS-CoV-2/physiology , Structure-Activity Relationship
12.
Biochem Pharmacol ; 192: 114724, 2021 10.
Article in English | MEDLINE | ID: covidwho-1347499

ABSTRACT

The COVID-19 pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has quickly spread around the globe. At present, there is no precise and effective treatment for the patients with COVID-19, so rapid development of drugs is urgently needed in order to contain the highly infectious disease. The virus spike protein (S protein) can recognize the angiotensin-converting enzyme 2 (ACE2) receptor on the host cell membrane and undergo a series of conformational changes, protease cleavage and membrane fusion to complete the virus entry, so S protein is an important target for vaccine and drug development. Here we provide a brief overview of molecular mechanisms of virus entry, as well as some potential antiviral agents that act on S/ACE2 protein-protein interaction. Specifically, we focused on experimentally validated and/or computational prediction identified inhibitors that target SARS-CoV-2 S protein, ACE2 and enzymes associated with viral infection. This review offers valuable information for the discovery and development of potential antiviral agents in combating SARS-CoV-2. In addition, with the deepening understanding of the mechanism of SARS-CoV-2 infection, more targeted prevention and treatment drugs will be explored with the aid of the advanced technology in the future.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , Antiviral Agents/administration & dosage , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/metabolism , Virus Internalization/drug effects , Angiotensin-Converting Enzyme 2/antagonists & inhibitors , Angiotensin-Converting Enzyme 2/immunology , Angiotensin-Converting Enzyme Inhibitors/administration & dosage , COVID-19/immunology , COVID-19/metabolism , COVID-19/prevention & control , Glycyrrhetinic Acid/administration & dosage , Humans , Protein Binding/drug effects , Protein Binding/physiology , SARS-CoV-2/immunology , Single-Chain Antibodies/administration & dosage , Spike Glycoprotein, Coronavirus/antagonists & inhibitors , Spike Glycoprotein, Coronavirus/immunology
13.
EMBO J ; 40(19): e108375, 2021 10 01.
Article in English | MEDLINE | ID: covidwho-1348811

ABSTRACT

New SARS-CoV-2 variants are continuously emerging with critical implications for therapies or vaccinations. The 22 N-glycan sites of Spike remain highly conserved among SARS-CoV-2 variants, opening an avenue for robust therapeutic intervention. Here we used a comprehensive library of mammalian carbohydrate-binding proteins (lectins) to probe critical sugar residues on the full-length trimeric Spike and the receptor binding domain (RBD) of SARS-CoV-2. Two lectins, Clec4g and CD209c, were identified to strongly bind to Spike. Clec4g and CD209c binding to Spike was dissected and visualized in real time and at single-molecule resolution using atomic force microscopy. 3D modelling showed that both lectins can bind to a glycan within the RBD-ACE2 interface and thus interferes with Spike binding to cell surfaces. Importantly, Clec4g and CD209c significantly reduced SARS-CoV-2 infections. These data report the first extensive map and 3D structural modelling of lectin-Spike interactions and uncovers candidate receptors involved in Spike binding and SARS-CoV-2 infections. The capacity of CLEC4G and mCD209c lectins to block SARS-CoV-2 viral entry holds promise for pan-variant therapeutic interventions.


Subject(s)
Receptors, Mitogen/metabolism , SARS-CoV-2/metabolism , Animals , Binding Sites/physiology , COVID-19/virology , Cell Line , Chlorocebus aethiops , Glycosylation , HEK293 Cells , Humans , Mice , Molecular Dynamics Simulation , Protein Binding/physiology , Vero Cells , Virus Internalization
14.
Biomed Pharmacother ; 142: 112011, 2021 Oct.
Article in English | MEDLINE | ID: covidwho-1340557

ABSTRACT

Since the start of the outbreak of coronavirus disease 2019 in Wuhan, China, there have been more than 150 million confirmed cases of the disease reported to the World Health Organization. The beta variant (B.1.351 lineage), the mutation lineages of SARS-CoV-2, had increase transmissibility and resistance to neutralizing antibodies due to multiple mutations in the spike protein. N501Y, K417N and E484K, in the receptor binding domain (RBD) region may induce a conformational change of the spike protein and subsequently increase the infectivity of the beta variant. The L452R mutation in the epsilon variant (the B.1.427/B.1.429 variants) also reduced neutralizing activity of monoclonal antibodies. In this study, we discovered that 300 µg/mL GB-2, from Tian Shang Sheng Mu of Chiayi Puzi Peitian Temple, can inhibit the binding between ACE2 and wild-type (Wuhan type) RBD spike protein. GB-2 can inhibit the binding between ACE2 and RBD with K417N-E484K-N501Y mutation in a dose-dependent manner. GB-2 inhibited the binding between ACE2 and the RBD with a single mutation (K417N or N501Y or L452R) except the E484K mutation. In the compositions of GB-2, glycyrrhiza uralensis Fisch. ex DC., theaflavin and (+)-catechin cannot inhibit the binding between ACE2 and wild-type RBD spike protein. Theaflavin 3-gallate can inhibit the binding between ACE2 and wild-type RBD spike protein. Our results suggest that GB-2 could be a potential candidate for the prophylaxis of some SARS-CoV-2 variants infection in the further clinical study because of its inhibition of binding between ACE2 and RBD with K417N-E484K-N501Y mutations or L452R mutation.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , Biflavonoids/pharmacology , COVID-19 , Catechin/pharmacology , Gallic Acid/analogs & derivatives , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Antibodies, Neutralizing/immunology , Antioxidants/pharmacology , Antiviral Agents/pharmacology , COVID-19/immunology , COVID-19/virology , Drug Discovery , Gallic Acid/pharmacology , HEK293 Cells , Humans , Medicine, East Asian Traditional , Mutation , Protein Binding/physiology , Protein Interaction Domains and Motifs/immunology , SARS-CoV-2/genetics , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism
15.
Cell ; 184(13): 3438-3451.e10, 2021 06 24.
Article in English | MEDLINE | ID: covidwho-1275185

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been spreading worldwide, causing a global pandemic. Bat-origin RaTG13 is currently the most phylogenetically related virus. Here we obtained the complex structure of the RaTG13 receptor binding domain (RBD) with human ACE2 (hACE2) and evaluated binding of RaTG13 RBD to 24 additional ACE2 orthologs. By substituting residues in the RaTG13 RBD with their counterparts in the SARS-CoV-2 RBD, we found that residue 501, the major position found in variants of concern (VOCs) 501Y.V1/V2/V3, plays a key role in determining the potential host range of RaTG13. We also found that SARS-CoV-2 could induce strong cross-reactive antibodies to RaTG13 and identified a SARS-CoV-2 monoclonal antibody (mAb), CB6, that could cross-neutralize RaTG13 pseudovirus. These results elucidate the receptor binding and host adaption mechanisms of RaTG13 and emphasize the importance of continuous surveillance of coronaviruses (CoVs) carried by animal reservoirs to prevent another spillover of CoVs.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , Binding Sites/physiology , COVID-19/metabolism , Chiroptera/virology , SARS-CoV-2/pathogenicity , Amino Acid Sequence , Animals , Antibodies, Monoclonal/immunology , COVID-19/immunology , Chiroptera/immunology , Chiroptera/metabolism , Host Specificity/immunology , Humans , Phylogeny , Protein Binding/physiology , Receptors, Virus/metabolism , SARS-CoV-2/immunology , Sequence Alignment
16.
J Med Virol ; 93(7): 4469-4479, 2021 07.
Article in English | MEDLINE | ID: covidwho-1263099

ABSTRACT

The outbreak of atypical pneumonia (coronavirus disease 2019 [COVID-19]) has been a global pandemic and has caused severe losses to the global economy. The virus responsible for COVID-9, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has a spike glycoprotein (S protein) that binds angiotensin-converting enzyme 2 (ACE2) present on host cell membranes to gain entry. Based on the full-length human ACE2 cryo-EM structure, we generated homology models of full-length ACE2 proteins from various species (gorilla, monkey, pig, bovine, sheep, cat, dog, mouse, and rat). Although these ACE2 molecules were found to share similar overall structures, their S-ACE2 interface residues differed. These differences likely result in variations in the ACE2 binding affinities to the SARS-CoV-2 S protein. The highest affinities are predicted for human, gorilla, and monkey, while mouse and rat ACE2 are predicted to have the lowest affinities. Cat ACE2 is predicted to have a lower S protein affinity than dog ACE2. Although affinity is not the only factor that affects viral susceptibility, it is one of the most important factors. Thus, we believe that care should be taken with these animals to prevent the spread of SARS-CoV-2 among animal and human populations.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , Receptors, Virus/metabolism , Spike Glycoprotein, Coronavirus/metabolism , Amino Acid Sequence/genetics , Angiotensin-Converting Enzyme 2/genetics , Animals , Binding Sites/physiology , COVID-19/virology , Cats , Cattle , Computer Simulation , Disease Susceptibility , Dogs , Gorilla gorilla , Haplorhini , Humans , Mice , Models, Molecular , Molecular Dynamics Simulation , Protein Binding/genetics , Protein Binding/physiology , Protein Conformation , Rats , SARS-CoV-2/metabolism , Sequence Alignment , Sheep , Swine
17.
J Pharmacol Sci ; 147(1): 62-71, 2021 Sep.
Article in English | MEDLINE | ID: covidwho-1240460

ABSTRACT

Owing to the urgent need for therapeutic interventions against the SARS-coronavirus 2 (SARS-CoV-2) pandemic, we employed an in silico approach to evaluate the SARS-CoV-2 inhibitory potential of newly synthesized imidazoles. The inhibitory potentials of the compounds against SARS-CoV-2 drug targets - main protease (Mpro), spike protein (Spro) and RNA-dependent RNA polymerase (RdRp) were investigated through molecular docking analysis. The binding free energy of the protein-ligand complexes were estimated, pharmacophore models were generated and the absorption, distribution, metabolism, excretion and toxicity (ADMET) properties of the compounds were determined. The compounds displayed various levels of binding affinities for the SARS-CoV-2 drug targets. Bisimidazole C2 scored highest against all the targets, with its aromatic rings including the two imidazole groups contributing to the binding. Among the phenyl-substituted 1H-imidazoles, C9 scored highest against all targets. C11 scored highest against Spro and C12 against Mpro and RdRp among the thiophene-imidazoles. The compounds interacted with HIS 41 - CYS 145 and GLU 288 - ASP 289 - GLU 290 of Mpro, ASN 501 of Spro receptor binding motif and some active site amino acids of RdRp. These novel imidazole compounds could be further developed as drug candidates against SARS-CoV-2 following lead optimization and experimental studies.


Subject(s)
Computational Biology/methods , Enzyme Inhibitors/pharmacology , Imidazoles/pharmacology , Molecular Docking Simulation/methods , SARS-CoV-2/drug effects , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/metabolism , Humans , Imidazoles/chemistry , Imidazoles/metabolism , Protein Binding/physiology , Protein Structure, Secondary , Protein Structure, Tertiary , SARS-CoV-2/chemistry , SARS-CoV-2/metabolism
18.
Cardiovasc Diabetol ; 20(1): 99, 2021 05 07.
Article in English | MEDLINE | ID: covidwho-1219133

ABSTRACT

RATIONALE: About 50% of hospitalized coronavirus disease 2019 (COVID-19) patients with diabetes mellitus (DM) developed myocardial damage. The mechanisms of direct SARS-CoV-2 cardiomyocyte infection include viral invasion via ACE2-Spike glycoprotein-binding. In DM patients, the impact of glycation of ACE2 on cardiomyocyte invasion by SARS-CoV-2 can be of high importance. OBJECTIVE: To evaluate the presence of SARS-CoV-2 in cardiomyocytes from heart autopsy of DM cases compared to Non-DM; to investigate the role of DM in SARS-COV-2 entry in cardiomyocytes. METHODS AND RESULTS: We evaluated consecutive autopsy cases, deceased for COVID-19, from Italy between Apr 30, 2020 and Jan 18, 2021. We evaluated SARS-CoV-2 in cardiomyocytes, expression of ACE2 (total and glycosylated form), and transmembrane protease serine protease-2 (TMPRSS2) protein. In order to study the role of diabetes on cardiomyocyte alterations, independently of COVID-19, we investigated ACE2, glycosylated ACE2, and TMPRSS2 proteins in cardiomyocytes from DM and Non-DM explanted-hearts. Finally, to investigate the effects of DM on ACE2 protein modification, an in vitro glycation study of recombinant human ACE2 (hACE2) was performed to evaluate the effects on binding to SARS-CoV-2 Spike protein. The authors included cardiac tissue from 97 autopsies. DM was diagnosed in 37 patients (38%). Fourth-seven out of 97 autopsies (48%) had SARS-CoV-2 RNA in cardiomyocytes. Thirty out of 37 DM autopsy cases (81%) and 17 out of 60 Non-DM autopsy cases (28%) had SARS-CoV-2 RNA in cardiomyocytes. Total ACE2, glycosylated ACE2, and TMPRSS2 protein expressions were higher in cardiomyocytes from autopsied and explanted hearts of DM than Non-DM. In vitro exposure of monomeric hACE2 to 120 mM glucose for 12 days led to non-enzymatic glycation of four lysine residues in the neck domain affecting the protein oligomerization. CONCLUSIONS: The upregulation of ACE2 expression (total and glycosylated forms) in DM cardiomyocytes, along with non-enzymatic glycation, could increase the susceptibility to COVID-19 infection in DM patients by favouring the cellular entry of SARS-CoV2.


Subject(s)
Angiotensin-Converting Enzyme 2/biosynthesis , COVID-19/metabolism , Diabetes Mellitus/metabolism , Myocytes, Cardiac/metabolism , SARS-CoV-2/metabolism , Aged , Amino Acid Sequence , Autopsy , COVID-19/epidemiology , COVID-19/pathology , Cohort Studies , Diabetes Mellitus/pathology , Female , Humans , Italy/epidemiology , Male , Middle Aged , Myocytes, Cardiac/pathology , Protein Binding/physiology , Protein Structure, Secondary
19.
Sci Adv ; 7(16)2021 04.
Article in English | MEDLINE | ID: covidwho-1186193

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) macrodomain within the nonstructural protein 3 counteracts host-mediated antiviral adenosine diphosphate-ribosylation signaling. This enzyme is a promising antiviral target because catalytic mutations render viruses nonpathogenic. Here, we report a massive crystallographic screening and computational docking effort, identifying new chemical matter primarily targeting the active site of the macrodomain. Crystallographic screening of 2533 diverse fragments resulted in 214 unique macrodomain-binders. An additional 60 molecules were selected from docking more than 20 million fragments, of which 20 were crystallographically confirmed. X-ray data collection to ultra-high resolution and at physiological temperature enabled assessment of the conformational heterogeneity around the active site. Several fragment hits were confirmed by solution binding using three biophysical techniques (differential scanning fluorimetry, homogeneous time-resolved fluorescence, and isothermal titration calorimetry). The 234 fragment structures explore a wide range of chemotypes and provide starting points for development of potent SARS-CoV-2 macrodomain inhibitors.


Subject(s)
Catalytic Domain/physiology , Protein Binding/physiology , Viral Nonstructural Proteins/metabolism , COVID-19/drug therapy , Catalytic Domain/genetics , Crystallography, X-Ray , Humans , Models, Molecular , Molecular Docking Simulation , Protein Conformation , SARS-CoV-2/genetics , SARS-CoV-2/physiology , Viral Nonstructural Proteins/genetics
20.
PLoS Pathog ; 17(4): e1009501, 2021 04.
Article in English | MEDLINE | ID: covidwho-1175434

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) protein mediates infection of cells expressing angiotensin-converting enzyme 2 (ACE2). ACE2 is also the viral receptor of SARS-CoV (SARS-CoV-1), a related coronavirus that emerged in 2002-2003. Horseshoe bats (genus Rhinolophus) are presumed to be the original reservoir of both viruses, and a SARS-like coronavirus, RaTG13, closely related to SARS-CoV-2, has been identified in one horseshoe-bat species. Here we characterize the ability of the S-protein receptor-binding domains (RBDs) of SARS-CoV-1, SARS-CoV-2, pangolin coronavirus (PgCoV), RaTG13, and LyRa11, a bat virus similar to SARS-CoV-1, to bind a range of ACE2 orthologs. We observed that the PgCoV RBD bound human ACE2 at least as efficiently as the SARS-CoV-2 RBD, and that both RBDs bound pangolin ACE2 efficiently. We also observed a high level of variability in binding to closely related horseshoe-bat ACE2 orthologs consistent with the heterogeneity of their RBD-binding regions. However five consensus horseshoe-bat ACE2 residues enhanced ACE2 binding to the SARS-CoV-2 RBD and neutralization of SARS-CoV-2 pseudoviruses by an enzymatically inactive immunoadhesin form of human ACE2 (hACE2-NN-Fc). Two of these mutations impaired neutralization of SARS-CoV-1 pseudoviruses. An hACE2-NN-Fc variant bearing all five mutations neutralized both SARS-CoV-2 pseudovirus and infectious virus more efficiently than wild-type hACE2-NN-Fc. These data suggest that SARS-CoV-1 and -2 originate from distinct bat species, and identify a more potently neutralizing form of soluble ACE2.


Subject(s)
Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/immunology , COVID-19/immunology , COVID-19/virology , Chiroptera/metabolism , SARS-CoV-2/genetics , Animals , COVID-19/genetics , Chiroptera/genetics , Host Specificity/genetics , Host Specificity/immunology , Humans , Models, Molecular , Mutation , Protein Binding/genetics , Protein Binding/physiology , Receptors, Virus/metabolism , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/metabolism
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