scholarly journals Using molecular dynamics simulations to prioritize and understand AI-generated cell penetrating peptides

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Duy Phuoc Tran ◽  
Seiichi Tada ◽  
Akiko Yumoto ◽  
Akio Kitao ◽  
Yoshihiro Ito ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
De Novo ◽  
Homology Modelling ◽  
Md Simulations ◽  
Cell Penetrating Peptides ◽  
Generative Models ◽  
Cell Penetrating ◽  
Wet Lab ◽  
Dynamics Simulations ◽  
De Novo Peptide

AbstractCell-penetrating peptides have important therapeutic applications in drug delivery, but the variety of known cell-penetrating peptides is still limited. With a promise to accelerate peptide development, artificial intelligence (AI) techniques including deep generative models are currently in spotlight. Scientists, however, are often overwhelmed by an excessive number of unannotated sequences generated by AI and find it difficult to obtain insights to prioritize them for experimental validation. To avoid this pitfall, we leverage molecular dynamics (MD) simulations to obtain mechanistic information to prioritize and understand AI-generated peptides. A mechanistic score of permeability is computed from five steered MD simulations starting from different initial structures predicted by homology modelling. To compensate for variability of predicted structures, the score is computed with sample variance penalization so that a peptide with consistent behaviour is highly evaluated. Our computational pipeline involving deep learning, homology modelling, MD simulations and synthesizability assessment generated 24 novel peptide sequences. The top-scoring peptide showed a consistent pattern of conformational change in all simulations regardless of initial structures. As a result of wet-lab-experiments, our peptide showed better permeability and weaker toxicity in comparison to a clinically used peptide, TAT. Our result demonstrates how MD simulations can support de novo peptide design by providing mechanistic information supplementing statistical inference.

scholarly journals Peptide-Ligand Binding Modeling of siRNA with Cell-Penetrating Peptides

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Alfonso T. García-Sosa ◽  
Indrek Tulp ◽  
Kent Langel ◽  
Ülo Langel
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Binding Affinity ◽  
Cell Penetrating Peptides ◽  
Peptide Ligand ◽  
Intermolecular Hydrogen Bonds ◽  
Cell Penetrating ◽  
The Stability ◽  
Dynamics Simulations ◽  
Explicit Water

The binding affinity of a series of cell-penetrating peptides (CPP) was modeled through docking and making use of the number of intermolecular hydrogen bonds, lipophilic contacts, and the number of sp3 molecular orbital hybridization carbons. The new ranking of the peptides is consistent with the experimentally determined efficiency in the downregulation of luciferase activity, which includes the peptides’ ability to bind and deliver the siRNA into the cell. The predicted structures of the complexes of peptides to siRNA were stable throughout 10 ns long, explicit water molecular dynamics simulations. The stability and binding affinity of peptide-siRNA complexes was related to the sidechains and modifications of the CPPs, with the stearyl and quinoline groups improving affinity and stability. The reranking of the peptides docked to siRNA, together with explicit water molecular dynamics simulations, appears to be well suited to describe and predict the interaction of CPPs with siRNA.

scholarly journals Molecular Dynamics Simulations of Mitochondrial Uncoupling Protein 2

2021 ◽  
Vol 22 (3) ◽  
pp. 1214
Author(s):  
Sanja Škulj ◽  
Zlatko Brkljača ◽  
Jürgen Kreiter ◽  
Elena E. Pohl ◽  
Mario Vazdar
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Proton Transport ◽  
Uncoupling Protein ◽  
Homology Modelling ◽  
Md Simulations ◽  
Phospholipid Bilayer ◽  
Mitochondrial Membranes ◽  
Fatty Acid Binding ◽  
Dynamics Simulations

Molecular dynamics (MD) simulations of uncoupling proteins (UCP), a class of transmembrane proteins relevant for proton transport across inner mitochondrial membranes, represent a complicated task due to the lack of available structural data. In this work, we use a combination of homology modelling and subsequent microsecond molecular dynamics simulations of UCP2 in the DOPC phospholipid bilayer, starting from the structure of the mitochondrial ATP/ADP carrier (ANT) as a template. We show that this protocol leads to a structure that is impermeable to water, in contrast to MD simulations of UCP2 structures based on the experimental NMR structure. We also show that ATP binding in the UCP2 cavity is tight in the homology modelled structure of UCP2 in agreement with experimental observations. Finally, we corroborate our results with conductance measurements in model membranes, which further suggest that the UCP2 structure modeled from ANT protein possesses additional key functional elements, such as a fatty acid-binding site at the R60 region of the protein, directly related to the proton transport mechanism across inner mitochondrial membranes.

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.

scholarly journals Molecular dynamics simulations and CD spectroscopy reveal hydration-induced unfolding of the intrinsically disordered LEA proteins COR15A and COR15B from Arabidopsis thaliana

2016 ◽  
Vol 18 (37) ◽  
pp. 25806-25816 ◽  
Author(s):  
Carlos Navarro-Retamal ◽  
Anne Bremer ◽  
Jans Alzate-Morales ◽  
Julio Caballero ◽  
Dirk K. Hincha ◽  
...  
Keyword(s):  
Experimental Data ◽  
Molecular Dynamics ◽  
Arabidopsis Thaliana ◽  
Molecular Dynamics Simulations ◽  
Md Simulations ◽  
Cd Spectroscopy ◽  
Lea Proteins ◽  
Intrinsically Disordered ◽  
Dynamics Simulations ◽  
Crowded Environment

Unfolding of intrinsically unstructured full-length LEA proteins in a differentially crowded environment can be modeled by 30 ns MD simulations in accordance with experimental data.

scholarly journals On the dynamics of some small structural motifs in rRNA upon ligand binding

2008 ◽  
Vol 73 (1) ◽  
pp. 41-53
Author(s):  
Aleksandra Rakic ◽  
Petar Mitrasinovic
Keyword(s):  
Molecular Dynamics ◽  
Conformational Changes ◽  
Binding Sites ◽  
De Novo ◽  
Reference Structure ◽  
Base Pairs ◽  
Rna Sequences ◽  
Conformational Model ◽  
Thermodynamic Variables ◽  
Dynamics Simulations

The present study characterizes using molecular dynamics simulations the behavior of the GAA (1186-1188) hairpin triloops with their closing c-g base pairs in large ribonucleoligand complexes (PDB IDs: 1njn, 1nwy, 1jzx). The relative energies of the motifs in the complexes with respect to that in the reference structure (unbound form of rRNA; PDB ID: 1njp) display the trends that agree with those of the conformational parameters reported in a previous study1 utilizing the de novo pseudotorsional (?,?) approach. The RNA regions around the actual RNA-ligand contacts, which experience the most substantial conformational changes upon formation of the complexes were identified. The thermodynamic parameters, based on a two-state conformational model of RNA sequences containing 15, 21 and 27 nucleotides in the immediate vicinity of the particular binding sites, were evaluated. From a more structural standpoint, the strain of a triloop, being far from the specific contacts and interacting primarily with other parts of the ribosome, was established as a structural feature which conforms to the trend of the average values of the thermodynamic variables corresponding to the three motifs defined by the 15-, 21- and 27-nucleotide sequences. From a more functional standpoint, RNA-ligand recognition is suggested to be presumably dictated by the types of ligands in the complexes.

scholarly journals Simulated Breathing: Application of Molecular Dynamics Simulations to Pulmonary Lung Surfactant

Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1259
Author(s):  
Maksymilian Dziura ◽  
Basel Mansour ◽  
Mitchell DiPasquale ◽  
P. Charukeshi Chandrasekera ◽  
James W. Gauld ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Pulmonary Surfactant ◽  
Lung Surfactant ◽  
Protein Composition ◽  
Md Simulations ◽  
Building Blocks ◽  
Future Research ◽  
Total Composition ◽  
Protein Components ◽  
Dynamics Simulations

In this review, we delve into the topic of the pulmonary surfactant (PS) system, which is present in the respiratory system. The total composition of the PS has been presented and explored, from the types of cells involved in its synthesis and secretion, down to the specific building blocks used, such as the various lipid and protein components. The lipid and protein composition varies across species and between individuals, but ultimately produces a PS monolayer with the same role. As such, the composition has been investigated for the ways in which it imposes function and confers peculiar biophysical characteristics to the system as a whole. Moreover, a couple of theories/models that are associated with the functions of PS have been addressed. Finally, molecular dynamic (MD) simulations of pulmonary surfactant have been emphasized to not only showcase various group’s findings, but also to demonstrate the validity and importance that MD simulations can have in future research exploring the PS monolayer system.

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