scholarly journals Multiple Virtual Screening Strategies for the Discovery of Novel Compounds Active Against Dengue Virus: A Hit Identification Study

2019 ◽  
Vol 88 (1) ◽  
pp. 2 ◽  
Author(s):  
Kowit Hengphasatporn ◽  
Arthur Garon ◽  
Peter Wolschann ◽  
Thierry Langer ◽  
Shigeta Yasuteru ◽  
...  
Keyword(s):  
Virtual Screening ◽  
Dengue Infection ◽  
Md Simulations ◽  
Viral Envelope ◽  
Screening Process ◽  
Active Inhibitor ◽  
Effective Prevention ◽  
E Protein ◽  
Drug Databases ◽  
Promising Target

Dengue infection is caused by a mosquito-borne virus, particularly in children, which may even cause death. No effective prevention or therapeutic agents to cure this disease are available up to now. The dengue viral envelope (E) protein was discovered to be a promising target for inhibition in several steps of viral infection. Structure-based virtual screening has become an important technique to identify first hits in a drug screening process, as it is possible to reduce the number of compounds to be assayed, allowing to save resources. In the present study, pharmacophore models were generated using the common hits approach (CHA), starting from trajectories obtained from molecular dynamics (MD) simulations of the E protein complexed with the active inhibitor, flavanone (FN5Y). Subsequently, compounds presented in various drug databases were screened using the LigandScout 4.2 program. The obtained hits were analyzed in more detail by molecular docking, followed by extensive MD simulations of the complexes. The highest-ranked compound from this procedure was then synthesized and tested on its inhibitory efficiency by experimental assays.

scholarly journals A benzene-mapping approach for uncovering cryptic pockets in membrane-bound proteins

2020 ◽  
Author(s):  
Lorena Zuzic ◽  
Jan K Marzinek ◽  
Jim Warwicker ◽  
Peter J Bond
Keyword(s):  
Conformational Changes ◽  
Viral Entry ◽  
Lipid Membrane ◽  
Membrane Lipids ◽  
Neutralizing Antibody ◽  
Md Simulations ◽  
Viral Envelope ◽  
E Protein ◽  
Repulsive Potentials ◽  
Functional Interface

ABSTRACTMolecular dynamics (MD) simulations in combination with small organic probes present in the solvent have previously been used as a method to reveal cryptic pockets that may not have been identified in experimental structures. We report such a method implemented within the CHARMM forcefield to effectively explore cryptic pockets on the surfaces of membrane-embedded proteins using benzene as a probe molecule. This relies on modified non-bonded parameters in addition to repulsive potentials between membrane lipids and benzene molecules. The method was tested on part of the outer shell of the dengue virus (DENV), for which research into a safe and effective neutralizing antibody or drug molecule is still ongoing. In particular, the envelope (E) protein, associated with the membrane (M) protein, is a lipid membrane-embedded complex which forms a dimer in the mature viral envelope. Solvent mapping was performed for the full, membrane-embedded EM protein complex and compared with similar calculations performed for the isolated, soluble E protein ectodomain dimer in solvent. Ectodomain-only simulations with benzene exhibited unfolding effects not observed in the more physiologically relevant membrane-associated systems. A cryptic pocket which has been experimentally shown to bind n-octyl-β-D-glucoside detergent was consistently revealed in all benzene-containing simulations. The addition of benzene also enhanced the flexibility and hydrophobic exposure of cryptic pockets at a key, functional interface in the E protein, and revealed a novel, potentially druggable pocket that may be targeted to prevent conformational changes associated with viral entry into the cell.GRAPHICAL ABSTRACT

scholarly journals Antiviral activity of silymarin and baicalein against dengue virus

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhao Xuan Low ◽  
Brian Ming OuYong ◽  
Pouya Hassandarvish ◽  
Chit Laa Poh ◽  
Babu Ramanathan
Keyword(s):  
Antiviral Activity ◽  
Dengue Virus ◽  
Viral Entry ◽  
Dengue Infection ◽  
Antiviral Agents ◽  
Antiviral Drug ◽  
Vero Cells ◽  
Viral Envelope ◽  
E Protein

AbstractDengue is an arthropod-borne viral disease that has become endemic and a global threat in many countries with no effective antiviral drug available currently. This study showed that flavonoids: silymarin and baicalein could inhibit the dengue virus in vitro and were well tolerated in Vero cells with a half-maximum cytotoxic concentration (CC50) of 749.70 µg/mL and 271.03 µg/mL, respectively. Silymarin and baicalein exerted virucidal effects against DENV-3, with a selective index (SI) of 10.87 and 21.34, respectively. Baicalein showed a better inhibition of intracellular DENV-3 progeny with a SI of 7.82 compared to silymarin. Baicalein effectively blocked DENV-3 attachment (95.59%) to the Vero cells, while silymarin prevented the viral entry (72.46%) into the cells, thus reducing viral infectivity. Both flavonoids showed promising antiviral activity against all four dengue serotypes. The in silico molecular docking showed that silymarin could bind to the viral envelope (E) protein with a binding affinity of − 8.5 kcal/mol and form hydrogen bonds with the amino acids GLN120, TRP229, ASN89, and THR223 of the E protein. Overall, this study showed that silymarin and baicalein exhibited potential anti-DENV activity and could serve as promising antiviral agents for further development against dengue infection.

The Research of New Inhibitors of Bacterial Methionine Aminopeptidase by Structure Based Virtual Screening Approach of ZINC DATABASE and In Vitro Validation

2020 ◽  
Vol 16 (4) ◽  
pp. 389-401 ◽  
Author(s):  
Hanane Boucherit ◽  
Abdelouahab Chikhi ◽  
Abderrahmane Bensegueni ◽  
Amina Merzoug ◽  
Jean-Michel Bolla
Keyword(s):  
Virtual Screening ◽  
Bacterial Survival ◽  
Methionine Aminopeptidase ◽  
Bacterial Strains ◽  
Microdilution Method ◽  
Zinc Database ◽  
Promising Target ◽  
New Antibiotics ◽  
Potential Inhibitors

Background: The great emergence of multi-resistant bacterial strains and the low renewal of antibiotics molecules are leading human and veterinary medicine to certain therapeutic impasses. Therefore, there is an urgent need to find new therapeutic alternatives including new molecules in the current treatments of infectious diseases. Methionine aminopeptidase (MetAP) is a promising target for developing new antibiotics because it is essential for bacterial survival. Objective: To screen for potential MetAP inhibitors by in silico virtual screening of the ZINC database and evaluate the best potential lead molecules by in vitro studies. Methods: We have considered 200,000 compounds from the ZINC database for virtual screening with FlexX software to identify potential inhibitors against bacterial MetAP. Nine chemical compounds of the top hits predicted were purchased and evaluated in vitro. The antimicrobial activity of each inhibitor of MetAP was tested by the disc-diffusion assay against one Gram-positive (Staphylococcus aureus) and two Gram-negative (Escherichia coli & Pseudomonas aeruginosa) bacteria. Among the studied compounds, compounds ZINC04785369 and ZINC03307916 showed promising antibacterial activity. To further characterize their efficacy, the minimum inhibitory concentration was determined for each compound by the microdilution method which showed significant results. Results: These results suggest compounds ZINC04785369 and ZINC03307916 as promising molecules for developing MetAP inhibitors. Conclusion: Furthermore, they could therefore serve as lead molecules for further chemical modifications to obtain clinically useful antibacterial agents.

scholarly journals Discovery of a Bradykinin B2 Partial Agonist Profile of Raloxifene in a Drug Repurposing Campaign

2020 ◽  
Vol 22 (1) ◽  
pp. 257
Author(s):  
Patricia Gomez-Gutierrez ◽  
Juan J. Perez
Keyword(s):  
Virtual Screening ◽  
Molecular Mechanisms ◽  
Partial Agonist ◽  
Drug Repurposing ◽  
Cytokine Storm ◽  
Bradykinin Receptors ◽  
Screening Process ◽  
Bradykinin Antagonists ◽  
Illness Progression

Covid-19 urges a deeper understanding of the underlying molecular mechanisms involved in illness progression to provide a prompt therapeutical response with an adequate use of available drugs, including drug repurposing. Recently, it was suggested that a dysregulated bradykinin signaling can trigger the cytokine storm observed in patients with severe Covid-19. In the scope of a drug repurposing campaign undertaken to identify bradykinin antagonists, raloxifene was identified as prospective compound in a virtual screening process. The pharmacodynamics profile of raloxifene towards bradykinin receptors is reported in the present work, showing a weak selective partial agonist profile at the B2 receptor. In view of this new profile, its possible use as a therapeutical agent for the treatment of severe Covid-19 is discussed.

scholarly journals Site-specific N-glycosylation analysis of animal cell culture-derived Zika virus proteins

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alexander Pralow ◽  
Alexander Nikolay ◽  
Arnaud Leon ◽  
Yvonne Genzel ◽  
Erdmann Rapp ◽  
...  
Keyword(s):  
Zika Virus ◽  
Animal Cell ◽  
Gradient Centrifugation ◽  
Viral Envelope ◽  
Protein Glycosylation ◽  
High Yield ◽  
Structural Protein ◽  
Site Specific ◽  
E Protein ◽  
The Impact

AbstractHere, we present for the first time, a site-specific N-glycosylation analysis of proteins from a Brazilian Zika virus (ZIKV) strain. The virus was propagated with high yield in an embryo-derived stem cell line (EB66, Valneva SE), and concentrated by g-force step-gradient centrifugation. Subsequently, the sample was proteolytically digested with different enzymes, measured via a LC–MS/MS-based workflow, and analyzed in a semi-automated way using the in-house developed glyXtoolMS software. The viral non-structural protein 1 (NS1) was glycosylated exclusively with high-mannose structures on both potential N-glycosylation sites. In case of the viral envelope (E) protein, no specific N-glycans could be identified with this method. Nevertheless, N-glycosylation could be proved by enzymatic de-N-glycosylation with PNGase F, resulting in a strong MS-signal of the former glycopeptide with deamidated asparagine at the potential N-glycosylation site N444. This confirmed that this site of the ZIKV E protein is highly N-glycosylated but with very high micro-heterogeneity. Our study clearly demonstrates the progress made towards site-specific N-glycosylation analysis of viral proteins, i.e. for Brazilian ZIKV. It allows to better characterize viral isolates, and to monitor glycosylation of major antigens. The method established can be applied for detailed studies regarding the impact of protein glycosylation on antigenicity and human pathogenicity of many viruses including influenza virus, HIV and corona virus.

scholarly journals Biophysical characterization of the SARS-CoV-2 E protein

2021 ◽  
Author(s):  
Aujan Mehregan ◽  
Sergio Perez-Conesa ◽  
Yuxuan Zhuang ◽  
Ahmad Elbahnsi ◽  
Diletta Pasini ◽  
...  
Keyword(s):  
Recombinant Expression ◽  
Structural Data ◽  
Md Simulations ◽  
Full Length ◽  
Coarse Grained ◽  
Biophysical Characterization ◽  
Viral Budding ◽  
Nmr Structures ◽  
E Protein

SARS-CoV-2 is the virus responsible for the COVID-19 pandemic which continues to wreak havoc across the world, over a year and a half after its effects were first reported in the general media. Current fundamental research efforts largely focus on the SARS-CoV-2 Spike protein. Since successful antiviral therapies are likely to target multiple viral components, there is considerable interest in understanding the biophysical role of its other proteins, in particular structural membrane proteins. Here, we have focused our efforts on the characterization of the full-length E protein from SARS-CoV-2, combining experimental and computational approaches. Recombinant expression of the full-length E protein from SARS-CoV-2 reveals that this membrane protein is capable of independent multimerization, possibly as a tetrameric or smaller species. Fluorescence microscopy shows that the protein localizes intracellularly, and coarse-grained MD simulations indicate it causes bending of the surrounding lipid bilayer, corroborating a potential role for the E protein in viral budding. Although we did not find robust electrophysiological evidence of ion-channel activity, cells transfected with the E protein exhibited reduced intracellular Ca2+, which may further promote viral replication. However, our atomistic MD simulations revealed that previous NMR structures are relatively unstable, and result in models incapable of ion conduction. Our study highlights the importance of using high-resolution structural data obtained from a full-length protein to gain detailed molecular insights, and eventually permitting virtual drug screening.

scholarly journals Zika E Glycan Loop Region and Guillain-Barré Syndrome-Related Proteins: A Possible Molecular Mimicry to be Taken in Account for Vaccine Development

2021 ◽  
Author(s):  
Lebeau Grégorie ◽  
Frumence Etienne ◽  
Turpin Jonathan ◽  
Hoarau Jean-jacques ◽  
Gadea Gilles ◽  
...  
Keyword(s):  
Autoimmune Diseases ◽  
Vaccine Development ◽  
Molecular Mimicry ◽  
In Silico Analysis ◽  
Neurological Complications ◽  
Viral Envelope ◽  
Loop Region ◽  
E Protein ◽  
Voltage Dependent ◽  
Related Proteins

Neurological complications of infection by the mosquito-borne Zika virus (ZIKV) include Guillain-Barré syndrome (GBS), an acute inflammatory demyelinating polyneuritis. GBS was first associated with recent ZIKV epidemics caused by the emergence of ZIKV Asian lineage in South Pacific. Here, we hypothesize that ZIKV-associated GBS relates to a molecular mimicry between viral envelope E (E) protein and neural proteins involved in GBS. Analysis of ZIKV epidemic strains showed that glycan loop (GL) region of the E protein includes an IVNDT motif which is conserved in voltage-dependent L-type calcium channel subunit alpha-1C (Cav1.2) and Heat Shock 70 kDa protein 12A (HSP70 12A). Both VSCC-alpha 1C and HSP70 12A belong to protein families which have been associated with neurological autoimmune diseases in central nervous system. The purpose of our in silico analysis is to point out that IVNDT motif of ZIKV E-GL region should be taken in consideration for the development of safe and effective anti-Zika vaccines by precluding the possibility of adverse neurologic events including autoimmune diseases such as GBS.

scholarly journals Characterization of the Coronavirus Mouse Hepatitis Virus Strain A59 Small Membrane Protein E

2000 ◽  
Vol 74 (5) ◽  
pp. 2333-2342 ◽  
Author(s):  
Martin J. B. Raamsman ◽  
Jacomine Krijnse Locker ◽  
Alphons de Hooge ◽  
Antoine A. F. de Vries ◽  
Gareth Griffiths ◽  
...  
Keyword(s):  
Virus Strain ◽  
Hepatitis Virus ◽  
Expression System ◽  
Mouse Hepatitis Virus ◽  
Viral Envelope ◽  
Membrane Structures ◽  
Electron Microscopic ◽  
E Protein ◽  
Infected Cells ◽  
Virus Expression

ABSTRACT The small envelope (E) protein has recently been shown to play an essential role in the assembly of coronaviruses. Expression studies revealed that for formation of the viral envelope, actually only the E protein and the membrane (M) protein are required. Since little is known about this generally low-abundance virion component, we have characterized the E protein of mouse hepatitis virus strain A59 (MHV-A59), an 83-residue polypeptide. Using an antiserum to the hydrophilic carboxy terminus of this otherwise hydrophobic protein, we found that the E protein was synthesized in infected cells with similar kinetics as the other viral structural proteins. The protein appeared to be quite stable both during infection and when expressed individually using a vaccinia virus expression system. Consistent with the lack of a predicted cleavage site, the protein was found to become integrated in membranes without involvement of a cleaved signal peptide, nor were any other modifications of the polypeptide observed. Immunofluorescence analysis of cells expressing the E protein demonstrated that the hydrophilic tail is exposed on the cytoplasmic side. Accordingly, this domain of the protein could not be detected on the outside of virions but appeared to be inside, where it was protected from proteolytic degradation. The results lead to a topological model in which the polypeptide is buried within the membrane, spanning the lipid bilayer once, possibly twice, and exposing only its carboxy-terminal domain. Finally, electron microscopic studies demonstrated that expression of the E protein in cells induced the formation of characteristic membrane structures also observed in MHV-A59-infected cells, apparently consisting of masses of tubular, smooth, convoluted membranes. As judged by their colabeling with antibodies to E and to Rab-1, a marker for the intermediate compartment and endoplasmic reticulum, the E protein accumulates in and induces curvature into these pre-Golgi membranes where coronaviruses have been shown earlier to assemble by budding.

scholarly journals Homology Modeling and Virtual Screening Studies of Antigen MLAA-42 Protein: Identification of Novel Drug Candidates against Leukemia—An In Silico Approach

2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Ihsan A. Shehadi ◽  
Huda R. M. Rashdan ◽  
Aboubakr H. Abdelmonsef
Keyword(s):  
Virtual Screening ◽  
Homology Modeling ◽  
Protein Identification ◽  
Binding Affinities ◽  
Monocytic Leukemia ◽  
Drug Candidates ◽  
Promising Target ◽  
Leukemia Treatment ◽  
Potent Drug ◽  
Novel Drug

Monocytic leukemia-associated antigen-42 (MLAA-42) is associated with excessive cell division and progression of leukemia. Thus, human MLAA-42 is considered as a promising target for designing of new lead molecules for leukemia treatment. Herein, the 3D model of the target was generated by homology modeling technique. The model was then evaluated using various cheminformatics servers. Moreover, the virtual screening studies were performed to explore the possible binding patterns of ligand molecules to MLAA’s active site pocket. Thirteen ligand molecules from the ChemBank™ database were identified as they showed good binding affinities, scaffold diversity, and preferential ADME properties which may act as potent drug candidates against leukemia. The study provides the way to identify novel therapeutics with optimal efficacy, targeting MLAA-42.

scholarly journals Identification of Potent VHZ Phosphatase Inhibitors with Structure-Based Virtual Screening

2012 ◽  
Vol 18 (2) ◽  
pp. 226-231 ◽  
Author(s):  
Hwangseo Park ◽  
So Ya Park ◽  
Jung Jin Oh ◽  
Seong Eon Ryu
Keyword(s):  
Virtual Screening ◽  
Active Site ◽  
Structural Features ◽  
Drug Candidate ◽  
The Novel ◽  
Anticancer Activities ◽  
Phosphatase Inhibitors ◽  
Structure Activity ◽  
Promising Target ◽  
Further Development

VH1-like phosphatase Z (VHZ) has proved to be a promising target for the development of therapeutics for the treatment of human cancers. Here, we report the first example for a successful application of structure-based virtual screening to identify the novel small-molecule inhibitors of VHZ. These inhibitors revealed high potencies with the associated IC50 values ranging from 3 to 20 µM and were also screened for having desirable physicochemical properties as a drug candidate. Therefore, they deserve consideration for further development by structure-activity relationship studies to optimize inhibitory and anticancer activities. Structural features relevant to the stabilization of the newly identified inhibitors in the active site of VHZ are discussed in detail.

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