scholarly journals In Silico Analysis of the Subtype Selective Blockage of KCNA Ion Channels through the µ-Conotoxins PIIIA, SIIIA, and GIIIA

Marine Drugs ◽  
2019 ◽  
Vol 17 (3) ◽  
pp. 180 ◽  
Author(s):  
Desirée Kaufmann ◽  
Alesia Tietze ◽  
Daniel Tietze
Keyword(s):  
In Silico Analysis ◽  
Binding Mode ◽  
Dynamic Simulations ◽  
Drug Candidates ◽  
Toxin Binding ◽  
Subtype Specificity ◽  
Pore Blockage ◽  
Natural Peptide ◽  
Dynamics Simulations ◽  
Subtype Selective

Understanding subtype specific ion channel pore blockage by natural peptide-based toxins is crucial for developing such compounds into promising drug candidates. Herein, docking and molecular dynamics simulations were employed in order to understand the dynamics and binding states of the µ-conotoxins, PIIIA, SIIIA, and GIIIA, at the voltage-gated potassium channels of the KV1 family, and they were correlated with their experimental activities recently reported by Leipold et al. Their different activities can only adequately be understood when dynamic information about the toxin-channel systems is available. For all of the channel-bound toxins investigated herein, a certain conformational flexibility was observed during the molecular dynamic simulations, which corresponds to their bioactivity. Our data suggest a similar binding mode of µ-PIIIA at KV1.6 and KV1.1, in which a plethora of hydrogen bonds are formed by the Arg and Lys residues within the α-helical core region of µ-PIIIA, with the central pore residues of the channel. Furthermore, the contribution of the K+ channel’s outer and inner pore loops with respect to the toxin binding. and how the subtype specificity is induced, were proposed.

scholarly journals The Repurposed Drugs Suramin and Quinacrine Cooperatively Inhibit SARS-CoV-2 3CLpro In Vitro

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 873
Author(s):  
Raphael J. Eberle ◽  
Danilo S. Olivier ◽  
Marcos S. Amaral ◽  
Ian Gering ◽  
Dieter Willbold ◽  
...  
Keyword(s):  
Binding Mode ◽  
Drug Candidates ◽  
Main Protease ◽  
Ic50 Values ◽  
Repurposed Drugs ◽  
Antiparasitic Drugs ◽  
Inhibitory Potential ◽  
Dynamics Simulations ◽  
Micromolar Range

Since the first report of a new pneumonia disease in December 2019 (Wuhan, China) the WHO reported more than 148 million confirmed cases and 3.1 million losses globally up to now. The causative agent of COVID-19 (SARS-CoV-2) has spread worldwide, resulting in a pandemic of unprecedented magnitude. To date, several clinically safe and efficient vaccines (e.g., Pfizer-BioNTech, Moderna, Johnson & Johnson, and AstraZeneca COVID-19 vaccines) as well as drugs for emergency use have been approved. However, increasing numbers of SARS-Cov-2 variants make it imminent to identify an alternative way to treat SARS-CoV-2 infections. A well-known strategy to identify molecules with inhibitory potential against SARS-CoV-2 proteins is repurposing clinically developed drugs, e.g., antiparasitic drugs. The results described in this study demonstrated the inhibitory potential of quinacrine and suramin against SARS-CoV-2 main protease (3CLpro). Quinacrine and suramin molecules presented a competitive and noncompetitive inhibition mode, respectively, with IC50 values in the low micromolar range. Surface plasmon resonance (SPR) experiments demonstrated that quinacrine and suramin alone possessed a moderate or weak affinity with SARS-CoV-2 3CLpro but suramin binding increased quinacrine interaction by around a factor of eight. Using docking and molecular dynamics simulations, we identified a possible binding mode and the amino acids involved in these interactions. Our results suggested that suramin, in combination with quinacrine, showed promising synergistic efficacy to inhibit SARS-CoV-2 3CLpro. We suppose that the identification of effective, synergistic drug combinations could lead to the design of better treatments for the COVID-19 disease and repurposable drug candidates offer fast therapeutic breakthroughs, mainly in a pandemic moment.

Clustering and Sampling of the c-Met Conformational Space: A Computational Drug Discovery Study

2020 ◽  
Vol 22 (9) ◽  
pp. 635-648 ◽  
Author(s):  
Korosh Mashayekh ◽  
Shahrzad Sharifi ◽  
Tahereh Damghani ◽  
Maryam Elyasi ◽  
Mohammad S. Avestan ◽  
...  
Keyword(s):  
Critical Role ◽  
Scientific Work ◽  
Binding Mode ◽  
Docking Studies ◽  
Conformational Space ◽  
Hydrogen Bond Interactions ◽  
Docking Program ◽  
Dynamics Simulations ◽  
Computational Drug Discovery ◽  
Dynamic Ensembles

Background: c-Met kinase plays a critical role in a myriad of human cancers, and a massive scientific work was devoted to design more potent inhibitors. Objective: In this study, 16 molecular dynamics simulations of different complexes of potent c-Met inhibitors with U-shaped binding mode were carried out regarding the dynamic ensembles to design novel potent inhibitors. Methods: A cluster analysis was performed, and the most representative frame of each complex was subjected to the structure-based pharmacophore screening. The GOLD docking program investigated the interaction energy and pattern of output hits from the virtual screening. The most promising hits with the highest scoring values that showed critical interactions with c-Met were presented for ADME/Tox analysis. Results: The screening yielded 45,324 hits that all of them were subjected to the docking studies and 10 of them with the highest-scoring values having diverse structures were presented for ADME/Tox analyses. Conclusion: The results indicated that all the hits shared critical Pi-Pi stacked and hydrogen bond interactions with Tyr1230 and Met1160 respectively.

scholarly journals Exploring aromatic cage flexibility of the histone methyllysine reader protein Spindlin1 and its impact on binding mode prediction: an in silico study

2021 ◽  
Author(s):  
Chiara Luise ◽  
Dina Robaa ◽  
Wolfgang Sippl
Keyword(s):  
Molecular Dynamic ◽  
In Silico ◽  
Binding Pocket ◽  
Binding Mode ◽  
Molecular Dynamic Simulations ◽  
Flexible Docking ◽  
Dynamic Simulations ◽  
Binding Mode Prediction ◽  
Aromatic Cage ◽  
The Right

AbstractSome of the main challenges faced in drug discovery are pocket flexibility and binding mode prediction. In this work, we explored the aromatic cage flexibility of the histone methyllysine reader protein Spindlin1 and its impact on binding mode prediction by means of in silico approaches. We first investigated the Spindlin1 aromatic cage plasticity by analyzing the available crystal structures and through molecular dynamic simulations. Then we assessed the ability of rigid docking and flexible docking to rightly reproduce the binding mode of a known ligand into Spindlin1, as an example of a reader protein displaying flexibility in the binding pocket. The ability of induced fit docking was further probed to test if the right ligand binding mode could be obtained through flexible docking regardless of the initial protein conformation. Finally, the stability of generated docking poses was verified by molecular dynamic simulations. Accurate binding mode prediction was obtained showing that the herein reported approach is a highly promising combination of in silico methods able to rightly predict the binding mode of small molecule ligands in flexible binding pockets, such as those observed in some reader proteins.

scholarly journals Pyrrolidine in Drug Discovery: A Versatile Scaffold for Novel Biologically Active Compounds

2021 ◽  
Vol 379 (5) ◽  
Author(s):  
Giovanna Li Petri ◽  
Maria Valeria Raimondi ◽  
Virginia Spanò ◽  
Ralph Holl ◽  
Paola Barraja ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Binding Mode ◽  
Biologically Active ◽  
Bioactive Molecules ◽  
Biological Profile ◽  
Pyrrolidine Ring ◽  
Reaction Conditions ◽  
Drug Candidates ◽  
Steric Factors ◽  
Proline Derivatives

AbstractThe five-membered pyrrolidine ring is one of the nitrogen heterocycles used widely by medicinal chemists to obtain compounds for the treatment of human diseases. The great interest in this saturated scaffold is enhanced by (1) the possibility to efficiently explore the pharmacophore space due to sp3-hybridization, (2) the contribution to the stereochemistry of the molecule, (3) and the increased three-dimensional (3D) coverage due to the non-planarity of the ring—a phenomenon called “pseudorotation”. In this review, we report bioactive molecules with target selectivity characterized by the pyrrolidine ring and its derivatives, including pyrrolizines, pyrrolidine-2-one, pyrrolidine-2,5-diones and prolinol described in the literature from 2015 to date. After a comparison of the physicochemical parameters of pyrrolidine with the parent aromatic pyrrole and cyclopentane, we investigate the influence of steric factors on biological activity, also describing the structure–activity relationship (SAR) of the studied compounds. To aid the reader’s approach to reading the manuscript, we have planned the review on the basis of the synthetic strategies used: (1) ring construction from different cyclic or acyclic precursors, reporting the synthesis and the reaction conditions, or (2) functionalization of preformed pyrrolidine rings, e.g., proline derivatives. Since one of the most significant features of the pyrrolidine ring is the stereogenicity of carbons, we highlight how the different stereoisomers and the spatial orientation of substituents can lead to a different biological profile of drug candidates, due to the different binding mode to enantioselective proteins. We believe that this work can guide medicinal chemists to the best approach in the design of new pyrrolidine compounds with different biological profiles.

scholarly journals Solvents to Fragments to Drugs: MD Applications in Drug Design

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3269 ◽  
Author(s):  
Lucas Defelipe ◽  
Juan Arcon ◽  
Carlos Modenutti ◽  
Marcelo Marti ◽  
Adrián Turjanski ◽  
...  
Keyword(s):  
Binding Free Energy ◽  
Mixed Solvents ◽  
Md Simulations ◽  
Binding Mode ◽  
Condensed State ◽  
Protein Targets ◽  
Drug Candidates ◽  
Interaction Sites ◽  
Aqueous Solvation ◽  
The Common

Simulations of molecular dynamics (MD) are playing an increasingly important role in structure-based drug discovery (SBDD). Here we review the use of MD for proteins in aqueous solvation, organic/aqueous mixed solvents (MDmix) and with small ligands, to the classic SBDD problems: Binding mode and binding free energy predictions. The simulation of proteins in their condensed state reveals solvent structures and preferential interaction sites (hot spots) on the protein surface. The information provided by water and its cosolvents can be used very effectively to understand protein ligand recognition and to improve the predictive capability of well-established methods such as molecular docking. The application of MD simulations to the study of the association of proteins with drug-like compounds is currently only possible for specific cases, as it remains computationally very expensive and labor intensive. MDmix simulations on the other hand, can be used systematically to address some of the common tasks in SBDD. With the advent of new tools and faster computers we expect to see an increase in the application of mixed solvent MD simulations to a plethora of protein targets to identify new drug candidates.

Molecular dynamic simulations of pressure-driven water transport through polyamide nanofiltration membranes at different membrane densities

RSC Advances ◽  
2016 ◽  
Vol 6 (68) ◽  
pp. 63586-63596 ◽  
Author(s):  
Luying Wang ◽  
Randall S. Dumont ◽  
James M. Dickson
Keyword(s):  
Molecular Dynamics ◽  
Porous Structure ◽  
Molecular Dynamic ◽  
Water Transport ◽  
Aromatic Polyamide ◽  
Molecular Dynamic Simulations ◽  
Nanofiltration Membranes ◽  
Dynamic Simulations ◽  
Dynamics Simulations ◽  
Pressure Driven

The amorphous aromatic polyamide membranes with different membrane densities were modeled to study the porous structure of free-volume pores and the pressure-driven water transport by using molecular dynamics simulations.

scholarly journals Conformational clamping by a membrane ligand activates the EphA2 receptor

2021 ◽  
Author(s):  
Justin M Westerfield ◽  
Amita Sahoo ◽  
Daiane S Alves ◽  
Brayan Grau ◽  
Alayna Cameron ◽  
...  
Keyword(s):  
Drug Target ◽  
Transmembrane Domain ◽  
Binding Mode ◽  
Membrane Receptors ◽  
Binding Motif ◽  
Active Conformation ◽  
Dynamic Simulations ◽  
Membrane Peptide ◽  
Migration Assays ◽  
Tm Domain

The EphA2 receptor is a promising drug target for cancer treatment, since EphA2 activation can inhibit metastasis and tumor progression. It has been recently described that the TYPE7 peptide activates EphA2 using a novel mechanism that involves binding to the single transmembrane domain of the receptor. TYPE7 is a conditional transmembrane (TM) ligand, which only inserts into membranes at neutral pH in the presence of the TM region of EphA2. However, how membrane interactions can activate EphA2 is not known. We systematically altered the sequence of TYPE7 to identify the binding motif used to activate EphA2. With the resulting six peptides, we performed biophysical and cell migration assays that identified a new potent peptide variant. We also performed a mutational screen that determined the helical interface that mediates dimerization of the TM domain of EphA2 in cells. These results, together with molecular dynamic simulations, allowed to elucidate the molecular mechanism that TYPE7 uses to activate EphA2, where the membrane peptide acts as a molecular clamp that wraps around the TM dimer of the receptor. We propose that this binding mode stabilizes the active conformation of EphA2. Our data, additionally, provide clues into the properties that TM ligands need to have in order to achieve activation of membrane receptors.

scholarly journals The substrate-binding cap of the UDP-diacylglucosamine pyrophosphatase LpxH is highly flexible, enabling facile substrate binding and product release

2018 ◽  
Vol 293 (21) ◽  
pp. 7969-7981 ◽  
Author(s):  
Thomas E. Bohl ◽  
Pek Ieong ◽  
John K. Lee ◽  
Thomas Lee ◽  
Jayakanth Kankanala ◽  
...  
Keyword(s):  
Rational Design ◽  
Substrate Binding ◽  
Flexible Substrate ◽  
Binding Mode ◽  
Antibiotic Development ◽  
Product Release ◽  
Outer Leaflet ◽  
Hydrogen Deuterium ◽  
Dynamics Simulations ◽  
Secondary Membrane

Gram-negative bacteria are surrounded by a secondary membrane of which the outer leaflet is composed of the glycolipid lipopolysaccharide (LPS), which guards against hydrophobic toxins, including many antibiotics. Therefore, LPS synthesis in bacteria is an attractive target for antibiotic development. LpxH is a pyrophosphatase involved in LPS synthesis, and previous structures revealed that LpxH has a helical cap that binds its lipid substrates. Here, crystallography and hydrogen–deuterium exchange MS provided evidence for a highly flexible substrate-binding cap in LpxH. Furthermore, molecular dynamics simulations disclosed how the helices of the cap may open to allow substrate entry. The predicted opening mechanism was supported by activity assays of LpxH variants. Finally, we confirmed biochemically that LpxH is inhibited by a previously identified antibacterial compound, determined the potency of this inhibitor, and modeled its binding mode in the LpxH active site. In summary, our work provides evidence that the substrate-binding cap of LpxH is highly dynamic, thus allowing for facile substrate binding and product release between the capping helices. Our results also pave the way for the rational design of more potent LpxH inhibitors.

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