scholarly journals Peptide Terminus Tilting: an Unusual conformational transition of MHC Class I Revealed by Molecular Dynamics Simulations

2017 ◽  
Author(s):  
Yeping Sun ◽  
Po Tian
Keyword(s):  
Molecular Dynamics ◽  
Antigen Presentation ◽  
Influenza A ◽  
Conformational Transition ◽  
Md Simulations ◽  
Lymphocytic Choriomeningitis ◽  
Class I ◽  
Accelerated Molecular Dynamics ◽  
Binding Pockets ◽  
Dynamics Simulations

ABSTRACTA conventional picture for major histocompatibility complex class I (MHCI) antigen presentation is that the terminal anchor residues of the antigenic peptide bind to the pockets at the bottom of the MHC cleft, leaving the central peptide residues exposed for T cell antigen receptor (TCR) recognition. However, in the present study, we show that in canonical or accelerated molecular dynamics (MD) simulations, the peptide terminus in some immunodominant peptide-MHCI (pMHCI) complexes can detach from their binding pockets and stretch outside the MHC cleft. These pMHCI complexes include the complex of the H-2Kb and the lymphocytic choriomeningitis virus (LCMV) gp33 peptide, and the complex of the HLA-A*0201 and the influenza A virus M1 peptide. The detached peptide terminus becomes the most prominent spot at the pMHC interface, and so can serves as a novel TCR recognition target. Thus, peptide terminus detaching may be a novel mechanism for MHC antigen presentation.

scholarly journals Accelerated molecular dynamics simulations of ligand binding to a muscarinic G-protein-coupled receptor

2015 ◽  
Vol 48 (4) ◽  
pp. 479-487 ◽  
Author(s):  
Kalli Kappel ◽  
Yinglong Miao ◽  
J. Andrew McCammon
Keyword(s):  
Molecular Dynamics ◽  
Ligand Binding ◽  
Binding Site ◽  
G Protein ◽  
Partial Agonist ◽  
Md Simulations ◽  
G Protein Coupled Receptor ◽  
Accelerated Molecular Dynamics ◽  
Dynamics Simulations ◽  
G Protein Coupled

AbstractElucidating the detailed process of ligand binding to a receptor is pharmaceutically important for identifying druggable binding sites. With the ability to provide atomistic detail, computational methods are well poised to study these processes. Here, accelerated molecular dynamics (aMD) is proposed to simulate processes of ligand binding to a G-protein-coupled receptor (GPCR), in this case the M3 muscarinic receptor, which is a target for treating many human diseases, including cancer, diabetes and obesity. Long-timescale aMD simulations were performed to observe the binding of three chemically diverse ligand molecules: antagonist tiotropium (TTP), partial agonist arecoline (ARc) and full agonist acetylcholine (ACh). In comparison with earlier microsecond-timescale conventional MD simulations, aMD greatly accelerated the binding of ACh to the receptor orthosteric ligand-binding site and the binding of TTP to an extracellular vestibule. Further aMD simulations also captured binding of ARc to the receptor orthosteric site. Additionally, all three ligands were observed to bind in the extracellular vestibule during their binding pathways, suggesting that it is a metastable binding site. This study demonstrates the applicability of aMD to protein–ligand binding, especially the drug recognition of GPCRs.

OMMProtocol: A Command Line Application to Launch Molecular Dynamics Simulations with OpenMM

2018 ◽  
Author(s):  
Jaime Rodríguez-Guerra Pedregal ◽  
Lur Alonso-Cotchico ◽  
Lorea Velasco-Carneros ◽  
Jean-Didier Maréchal
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Md Simulations ◽  
Third Party ◽  
Command Line ◽  
Input File ◽  
Accelerated Molecular Dynamics ◽  
Multi Stage ◽  
Simulation Protocol ◽  
Dynamics Simulations

<p>OpenMM is a free and GPU-accelerated Molecular Dynamics (MD) engine written as a layered and reusable library. This approach allows maximum flexibility to configure MD simulations and develop new molecular mechanics (MM) methods. However, this powerful versatility comes at a cost: the user is expected to write Python scripts to run a simulation. OMMProtocol aims to fill this gap by stitching OpenMM and additional third-party modules together, providing an easy way to create an input file to configure a full multi-stage simulation protocol, from minimization to equilibration and production. OMMProtocol is LGPL-licensed and freely available at <a href="https://github.com/insilichem/ommprotocol">https://github.com/insilichem/ommprotocol</a>. </p>

OMMProtocol: A Command Line Application to Launch Molecular Dynamics Simulations with OpenMM

2018 ◽  
Author(s):  
Jaime Rodríguez-Guerra Pedregal ◽  
Lur Alonso-Cotchico ◽  
Lorea Velasco-Carneros ◽  
Jean-Didier Maréchal
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Md Simulations ◽  
Third Party ◽  
Command Line ◽  
Input File ◽  
Accelerated Molecular Dynamics ◽  
Multi Stage ◽  
Simulation Protocol ◽  
Dynamics Simulations

<p>OpenMM is a free and GPU-accelerated Molecular Dynamics (MD) engine written as a layered and reusable library. This approach allows maximum flexibility to configure MD simulations and develop new molecular mechanics (MM) methods. However, this powerful versatility comes at a cost: the user is expected to write Python scripts to run a simulation. OMMProtocol aims to fill this gap by stitching OpenMM and additional third-party modules together, providing an easy way to create an input file to configure a full multi-stage simulation protocol, from minimization to equilibration and production. OMMProtocol is LGPL-licensed and freely available at <a href="https://github.com/insilichem/ommprotocol">https://github.com/insilichem/ommprotocol</a>. </p>

scholarly journals Exploring the conformational transition between the fully folded and locally unfolded substates of Escherichia coli thiol peroxidase

2020 ◽  
Vol 22 (17) ◽  
pp. 9518-9533
Author(s):  
Diego S. Vazquez ◽  
Ari Zeida ◽  
William A. Agudelo ◽  
Mónica R. Montes ◽  
Gerardo Ferrer-Sueta ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Conformational Transition ◽  
Accelerated Molecular Dynamics ◽  
Thiol Peroxidase ◽  
Dynamics Simulations ◽  
Conformational Substate

Temporal acquisition of the fully folded conformational substate of the Escherichia coli thiol peroxidase by accelerated molecular dynamics simulations.

scholarly journals Deciphering collaborative sidechain motions in proteins during molecular dynamics simulations

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Bruck Taddese ◽  
Antoine Garnier ◽  
Hervé Abdi ◽  
Daniel Henrion ◽  
Marie Chabbert
Keyword(s):  
Molecular Dynamics ◽  
Large Scale ◽  
Conformational Transition ◽  
Transmembrane Helix ◽  
Principal Component ◽  
Dynamic Structure ◽  
Md Simulations ◽  
Outward Motion ◽  
Dynamics Simulations

Abstract The dynamic structure of proteins is essential for their functions and may include large conformational transitions which can be studied by molecular dynamics (MD) simulations. However, details of these transitions are difficult to automatically track. To facilitate their analysis, we developed two scores of correlation between sidechain dihedral angles. The CIRCULAR and OMES scores are computed from, respectively, dihedral angle values and rotamer distributions. As a case study, we applied our methods to an activation-like transition of the chemokine receptor CXCR4, observed during accelerated MD simulations. The principal component analysis of the correlation matrices was consistent with the networking structure of the top ranking pairs. Both scores identify a set of residues whose “collaborative” sidechain rotamerization immediately preceded or accompanied the conformational transition of CXCR4. Detailed analysis of the sequential order of these rotamerizations suggests that an allosteric mechanism, involving the outward motion of an asparagine residue in transmembrane helix 3, might be a prerequisite to the large scale conformational transition of CXCR4. This case study provides the proof-of-concept that the correlation methods developed here are valuable exploratory techniques to help decipher complex reactional pathways.

Assessing the Antimalarial Potentials of Phytochemicals: Virtual Screening, Molecular Dynamics and In-Vitro Investigations

2019 ◽  
Vol 16 (3) ◽  
pp. 291-300
Author(s):  
Saumya K. Patel ◽  
Mohd Athar ◽  
Prakash C. Jha ◽  
Vijay M. Khedkar ◽  
Yogesh Jasrai ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Structural Integrity ◽  
Md Simulations ◽  
Tylophora Indica ◽  
Multidrug Resistance Protein 1 ◽  
Receptor Complexes ◽  
Resistance Protein ◽  
Dynamics Simulations ◽  
Stable Trajectory

Background: Combined in-silico and in-vitro approaches were adopted to investigate the antiplasmodial activity of Catharanthus roseus and Tylophora indica plant extracts as well as their isolated components (vinblastine, vincristine and tylophorine). </P><P> Methods: We employed molecular docking to prioritize phytochemicals from a library of 26 compounds against Plasmodium falciparum multidrug-resistance protein 1 (PfMDR1). Furthermore, Molecular Dynamics (MD) simulations were performed for a duration of 10 ns to estimate the dynamical structural integrity of ligand-receptor complexes. </P><P> Results: The retrieved bioactive compounds viz. tylophorine, vinblastin and vincristine were found to exhibit significant interacting behaviour; as validated by in-vitro studies on chloroquine sensitive (3D7) as well as chloroquine resistant (RKL9) strain. Moreover, they also displayed stable trajectory (RMSD, RMSF) and molecular properties with consistent interaction profile in molecular dynamics simulations. </P><P> Conclusion: We anticipate that the retrieved phytochemicals can serve as the potential hits and presented findings would be helpful for the designing of malarial therapeutics.

scholarly journals Unveiling Carbon Dioxide and Ethanol Diffusion in Carbonated Water-Ethanol Mixtures by Molecular Dynamics Simulations

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1711
Author(s):  
Mohamed Ahmed Khaireh ◽  
Marie Angot ◽  
Clara Cilindre ◽  
Gérard Liger-Belair ◽  
David A. Bonhommeau
Keyword(s):  
Carbon Dioxide ◽  
Molecular Dynamics ◽  
Diffusion Coefficients ◽  
Hydrodynamic Radius ◽  
Md Simulations ◽  
Molecular Models ◽  
Experimental Values ◽  
Carbon Dioxide Co2 ◽  
Dynamics Simulations ◽  
Apparent Disagreement

The diffusion of carbon dioxide (CO2) and ethanol (EtOH) is a fundamental transport process behind the formation and growth of CO2 bubbles in sparkling beverages and the release of organoleptic compounds at the liquid free surface. In the present study, CO2 and EtOH diffusion coefficients are computed from molecular dynamics (MD) simulations and compared with experimental values derived from the Stokes-Einstein (SE) relation on the basis of viscometry experiments and hydrodynamic radii deduced from former nuclear magnetic resonance (NMR) measurements. These diffusion coefficients steadily increase with temperature and decrease as the concentration of ethanol rises. The agreement between theory and experiment is suitable for CO2. Theoretical EtOH diffusion coefficients tend to overestimate slightly experimental values, although the agreement can be improved by changing the hydrodynamic radius used to evaluate experimental diffusion coefficients. This apparent disagreement should not rely on limitations of the MD simulations nor on the approximations made to evaluate theoretical diffusion coefficients. Improvement of the molecular models, as well as additional NMR measurements on sparkling beverages at several temperatures and ethanol concentrations, would help solve this issue.

Mechanism of stacking fault annihilation in 3C-SiC epitaxially grown on Si(001) by molecular dynamics simulations

CrystEngComm ◽  
2021 ◽  
Author(s):  
Andrey Sarikov ◽  
Anna Marzegalli ◽  
Luca Barbisan ◽  
Massimo Zimbone ◽  
Corrado Bongiorno ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Stacking Faults ◽  
Md Simulations ◽  
Stacking Fault ◽  
Dynamics Simulations

In this work, annihilation mechanism of stacking faults (SFs) in epitaxial 3C-SiC layers grown on Si(001) substrates is studied by molecular dynamics (MD) simulations. The evolution of SFs located in...

scholarly journals Molecular Dynamics Simulations of Crystal Nucleation near Interfaces in Incompatible Polymer Blends

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 347
Author(s):  
Wenlin Zhang ◽  
Lingyi Zou
Keyword(s):  
Molecular Dynamics ◽  
Polymer Blends ◽  
Md Simulations ◽  
Nucleation And Growth ◽  
Crystal Nucleation ◽  
Crystalline Order ◽  
Mobile Species ◽  
Deep Supercooling ◽  
Crystallizable Polymer ◽  
Dynamics Simulations

We apply molecular dynamics (MD) simulations to investigate crystal nucleation in incompatible polymer blends under deep supercooling conditions. Simulations of isothermal nucleation are performed for phase-separated blends with different degrees of incompatibility. In weakly segregated blends, slow and incompatible chains in crystallizable polymer domains can significantly hinder the crystal nucleation and growth. When a crystallizable polymer is blended with a more mobile species in interfacial regions, enhanced molecular mobility leads to the fast growth of crystalline order. However, the incubation time remains the same as that in pure samples. By inducing anisotropic alignment near the interfaces of strongly segregated blends, phase separation also promotes crystalline order to grow near interfaces between different polymer domains.

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