scholarly journals Automated Coarse-Grained Mapping Algorithm for the Martini Force Field and Benchmarks for Membrane–Water Partitioning

Author(s):  
Thomas D. Potter ◽  
Elin L. Barrett ◽  
Mark A. Miller
2017 ◽  
Vol 146 (5) ◽  
pp. 054501 ◽  
Author(s):  
Julian Michalowsky ◽  
Lars V. Schäfer ◽  
Christian Holm ◽  
Jens Smiatek

2020 ◽  
Author(s):  
Luis Itza Vazquez-Salazar ◽  
Michele Selle ◽  
Alex H. de Vries ◽  
Siewert-Jan Marrink ◽  
Paulo C. T. Souza

<div> <div> <div> <p>Ionic liquids (IL) are remarkable green solvents, which find applications in many areas of nano- and biotechnology including extraction and purification of value-added compounds or fine chemicals. These liquid salts possess versatile solvation properties that can be tuned by modifications in the cation or anion structure. So far, in contrast to the great success of theoretical and computational methodologies applied to other fields, only a few IL models have been able to bring insights towards the rational design of such solvents. In this work, we develop coarse-grained (CG) models for imidazolium-based ILs using a new version of the Martini force field. The model is able to reproduce the main structural properties of pure ILs, including spatial heterogeneity and global densities over a wide range of temperatures. More importantly, given the high intermolecular compatibility of the Martini force field, this new IL CG model opens the possibility of large-scale simulations of liquid-liquid extraction experiments. As examples, we show two applications, namely the extraction of aromatic molecules from a petroleum oil model and the extraction of omega-3 polyunsaturated fatty acids from a fish oil model. In semi-quantitative agreement with the experiments, we show how the extraction capacity and selectivity of the IL could be affected by the cation chain length or addition of co-solvents. </p> </div> </div> </div>


2021 ◽  
Author(s):  
Xiang-feng Jia ◽  
Jing-fei Chen ◽  
Hui-xue Ren ◽  
Qi Wang ◽  
Wen Xu ◽  
...  

Abstract Through analyzing the deficiency of the current coarse-grained (CG) model, a new CG model for the ionic surfactant was proposed based on the Martini force field and iterative Boltzmann inversion method. In this model, the electrostatic interaction can be tackled by using a self-defined piecewise function to avoid the disadvantage of using coarse-grained solvents, and the VDW interaction parameters were derived by iterative methods. Using the improved model, the radial distribution function of NaCl and SDS solution in all-atom OPLS can be completely reproduced. The successful setup of the new coarse-grained model provides a good example of the construction of a high-precision coarse-grained force field.


2015 ◽  
Vol 11 (9) ◽  
pp. 4486-4494 ◽  
Author(s):  
Yifei Qi ◽  
Helgi I. Ingólfsson ◽  
Xi Cheng ◽  
Jumin Lee ◽  
Siewert J. Marrink ◽  
...  

Author(s):  
Mauricio P. Sica ◽  
Cristian R. Smulski

The Tumor Necrosis Factor (TNF) and the TNF receptor (TNFR) superfamilies are composed of 19 ligands and 30 receptors, respectively. The oligomeric properties of ligands, both membrane bound and soluble, has been studied most. However, less is known about the oligomeric properties of TNFRs. Earlier reports identified the extracellular, membrane-distal, cysteine-rich domain as a pre-ligand assembly domain which stabilizes receptor dimers and/or trimers in the absence of ligand. Nevertheless, recent reports based on structural nuclear magnetic resonance (NMR) highlight the intrinsic role of the transmembrane domains to form dimers (p75NTR), trimers (Fas), or dimers of trimers (DR5). Thus, understanding the structural basis of transmembrane oligomerization may shed light on the mechanism for signal transduction and the impact of disease-associated mutations in this region. To this end, here we used an in silico coarse grained molecular dynamics approach with Martini force field to study TNFR transmembrane homotypic interactions. We have first validated this approach studying the three TNFR described by NMR (p75NTR, Fas, and DR5). We have simulated membrane patches composed of 36 helices of the same receptor equidistantly distributed in order to get unbiassed information on spontaneous proteins assemblies. Good agreement was found in the specific residues involved in homotypic interactions and we were able to observe dimers, trimers, and higher-order oligomers corresponding to those reported in NMR experiments. We have, applied this approach to study the assembly of disease-related mutations being able to assess their impact on oligomerization stability. In conclusion, our results showed the usefulness of coarse grained simulations with Martini force field to study in an unbiased manner higher order transmembrane oligomerization.


Polymers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 4044
Author(s):  
Jiramate Kitjanon ◽  
Wasinee Khuntawee ◽  
Saree Phongphanphanee ◽  
Thana Sutthibutpong ◽  
Nattaporn Chattham ◽  
...  

The mechanical properties of natural rubber (NR) composites depend on many factors, including the filler loading, filler size, filler dispersion, and filler-rubber interfacial interactions. Thus, NR composites with nano-sized fillers have attracted a great deal of attention for improving properties such as stiffness, chemical resistance, and high wear resistance. Here, a coarse-grained (CG) model based on the MARTINI force field version 2.1 has been developed and deployed for simulations of cis-1,4-polyisoprene (cis-PI). The model shows qualitative and quantitative agreement with the experiments and atomistic simulations. Interestingly, only a 0.5% difference with respect to the experimental result of the glass transition temperature (Tg) of the cis-PI in the melts was observed. In addition, the mechanical and thermodynamical properties of the cis-PI-fullerene(C60) composites were investigated. Coarse-grained molecular dynamics (MD) simulations of cis-PI-C60 composites with varying fullerene concentrations (0–32 parts per hundred of rubber; phr) were performed over 200 microseconds. The structural, mechanical, and thermal properties of the composites were determined. The density, bulk modulus, thermal expansion, heat capacity, and Tg of the NR composites were found to increase with increasing C60 concentration. The presence of C60 resulted in a slight increasing of the end-to-end distance and radius of the gyration of the cis-PI chains. The contribution of C60 and cis-PI interfacial interactions led to an enhancement of the bulk moduli of the composites. This model should be helpful in the investigations and design of effective fillers of NR-C60 composites for improving their properties.


2007 ◽  
Vol 111 (27) ◽  
pp. 7812-7824 ◽  
Author(s):  
Siewert J. Marrink ◽  
H. Jelger Risselada ◽  
Serge Yefimov ◽  
D. Peter Tieleman ◽  
Alex H. de Vries

2020 ◽  
Vol 22 (21) ◽  
pp. 7376-7386 ◽  
Author(s):  
Luis Itza Vazquez-Salazar ◽  
Michele Selle ◽  
Alex H. de Vries ◽  
Siewert J. Marrink ◽  
Paulo C. T. Souza

New coarse-grained models for imidazolium-based ionic liquids (ILs) were developed using the Martini force field. They were able to not only reproduce the structural properties but also allow simulations of liquid–liquid extraction experiments.


2021 ◽  
Vol 2108 (1) ◽  
pp. 012085
Author(s):  
Mingjia Fang

Abstract During the past few years, numerous studies have been done in self-assembly. Among most of these studies, Molecular Dynamic Simulation is widely used to construct the experiment model. This work firstly introduced three practical applications of MD simulation in self-assembly. Then, two main kinds of simulation are discussed including all-atom simulation and coarse-grained simulation, together with the way of thoughts before the simulation start. It is found that researchers always start with the whole analysis of the substances that need to be studied. It helps to confirm the appropriate model that can apply in the simulation naturally. Besides, depended on the principles that need to be studied, the way of establishing the simulation system varies, ranging from separation experiment in both types of simulation to the change of essential parameters. Furthermore, the adoption of L-J potential in MD simulation proves to be a wise option on account of its convenient and simple model. It is remarkable that, considering some small details like the differences between implicit and explicit solution, classical Martini force field is replaced by Dry Martini force field.


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