scholarly journals Binding of Ca2+-independent C2 domains to lipid membranes: A multi-scale molecular dynamics study

Structure ◽  
2021 ◽  
Author(s):  
Andreas Haahr Larsen ◽  
Mark S.P. Sansom
Author(s):  
P. Rangamani ◽  
D. J. Steigmann

A continuum theory for lipid membranes is developed that accounts for mechanical interactions between lipid tilt and membrane shape. For planar membranes, a linear version of the theory is used to predict tilt variations similar to those observed in experiments and molecular dynamics simulations.


Author(s):  
William W. F. Chong ◽  
Hedong Zhang

Using Molecular Dynamics (MD) simulation, the current study determined the surface forces between iron oxide surfaces when immersed in methyl oleate. Condensed-phase Optimized Molecular Potentials for Atomistic Simulation Studies (COMPASS) force field was used to model the methyl oleate molecules. For the nano-confinement simulation, the iron oxide wall was modelled from its crystal structure. The nano-confinement simulation model was setup in a manner where the confined methyl oleate molecules were in contact with the bulk molecules surrounding each side of the iron oxide walls. Through the simulation, the load-separation gap profile was obtained by reducing the separation gap between the ferric oxide walls. When the separation gap was reduced from 2.75 nm to 1.88 nm, the load is shown to increase monotonically. Such increase in load bearing ability of the contact is observed to correspond to a more densely packed methyl oleate molecules, reflected by four well-formed layers across the separation gap. As the gap is dropped from 1.88 nm to 1.63 nm, the load instead reduces, indicating deteriorating load bearing ability of the contact. However, the load bearing ability of the contact is then shown to recover when the gap was further reduced till 1.38 nm. This oscillatory load trend is shown to be as a result of a layer of methyl oleate molecules being squeezed out of contact, corroborated by the density profile change where four well-formed layers were reduced to only three layers from 1.88 nm to 1.38 nm gap. This also indicates that the simulated contact exhibits structural forces, known as solvation forces. Thus, the MD simulation discussed in this study is demonstrated to be capable of providing a foundation to allow for a multi-scale simulation, integrating various force laws at different length scales, to study larger scale tribological contacts.


RSC Advances ◽  
2015 ◽  
Vol 5 (83) ◽  
pp. 68227-68233 ◽  
Author(s):  
Jipeng Li ◽  
Yiyun Ouyang ◽  
Xian Kong ◽  
Jingying Zhu ◽  
Diannan Lu ◽  
...  

PMAL as a novel carrier for the delivery of siRNA into lipid bilayer membranes.


2021 ◽  
Author(s):  
Tom Pace ◽  
Hadi Rahmaninejad ◽  
Bin Sun ◽  
Peter Kekenes-Huskey

Silica-based materials including zeolites are commonly used for wide ranging applications including separations and catalysis.<br>Substrate transport rates in these materials often significantly influence the efficiency of such applications.<br>Two factors that contribute to transport rates include<br>1) the porosity of the silicate matrix and<br>2) non-bonding interactions between the diffusing species and the silicate surface.<br>Here, we utilize computer simulation to resolve the relative contribution of these factors to effective methane transport rates in a silicate channel.<br>Specifically, we develop a `homogenized' model of methane transport valid at micron and longer length scales that incorporates atomistic-scale kinetic information.<br>The atomistic-scale data are obtained from extensive molecular dynamics simulations that yield local diffusion coefficients and potentials of mean force.<br>With this model, we demonstrate how nuances in silicate hydration and silica/methane interactions impact 'macroscale' methane diffusion rates in bulk silicate materials.<br>This hybrid homogenization/molecular dynamics approach will be of general use for describing small molecule transport in materials with detailed molecular interactions.<br><br>


2021 ◽  
Vol 14 (10) ◽  
pp. 1062
Author(s):  
Tomasz Róg ◽  
Mykhailo Girych ◽  
Alex Bunker

We review the use of molecular dynamics (MD) simulation as a drug design tool in the context of the role that the lipid membrane can play in drug action, i.e., the interaction between candidate drug molecules and lipid membranes. In the standard “lock and key” paradigm, only the interaction between the drug and a specific active site of a specific protein is considered; the environment in which the drug acts is, from a biophysical perspective, far more complex than this. The possible mechanisms though which a drug can be designed to tinker with physiological processes are significantly broader than merely fitting to a single active site of a single protein. In this paper, we focus on the role of the lipid membrane, arguably the most important element outside the proteins themselves, as a case study. We discuss work that has been carried out, using MD simulation, concerning the transfection of drugs through membranes that act as biological barriers in the path of the drugs, the behavior of drug molecules within membranes, how their collective behavior can affect the structure and properties of the membrane and, finally, the role lipid membranes, to which the vast majority of drug target proteins are associated, can play in mediating the interaction between drug and target protein. This review paper is the second in a two-part series covering MD simulation as a tool in pharmaceutical research; both are designed as pedagogical review papers aimed at both pharmaceutical scientists interested in exploring how the tool of MD simulation can be applied to their research and computational scientists interested in exploring the possibility of a pharmaceutical context for their research.


2018 ◽  
Vol 209 ◽  
pp. 341-358 ◽  
Author(s):  
Martin Vögele ◽  
Jürgen Köfinger ◽  
Gerhard Hummer

Carbon nanotube porins embedded in lipid membranes are studied by molecular dynamics simulations.


2005 ◽  
Vol 29 (3) ◽  
pp. 403-421
Author(s):  
Kamran Behdinan ◽  
Yigui Xu ◽  
Zouheir Fawaz

A new technique called Molecular Element Method is proposed for multi-scale modeling and simulations of nano/micro-systems. In this technique, the system is divided into molecular elements whose properties are represented by sets of equivalent physical parameters obtained from atomic information. The discrete system is solved based on continuum mechanics theories. The resultant element information from system solving is then used as an external constraint for the elements, to investigate the atomic information within, using molecular dynamics calculations. Both system properties and atomic information at local zones can be obtained accurately and efficiently in this way, A crystal of Cu having 285,883 atoms with a through the thickness hole inside is investigated using this technique. Tension stresses of the crystal and the slip of atoms around the hole’s edge are revealed corresponding to five strain loads. Compared with the results obtained from the classical molecular dynamics method, the maximum stress error is 2.7%, while the computational time is only 7.2-11.8% of that taken by the classical method.


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