Dynamic Clustering Regulates Activity of Mechanosensitive Membrane Channels

2021

Soft Matter

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Section: Surface Stretching and Volume Adaptation Are Coupled To The mentioning

confidence: 99%

Modelling the dynamics of vesicle reshaping and scission under osmotic shocks

Campos

2021

Soft Matter

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Section: Resultsmentioning

confidence: 99%

Modelling the dynamics of vesicle reshaping and scission under osmotic shocks

Campos

2020

Preprint

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We study the effects of osmotic shocks on lipid vesicles via coarse-grained molecular dynamics simulations by explicitly considering the solute in the system. We find that depending on their nature (hypo- or hypertonic) such shocks can lead to bursting events or engulfing of external material into inner compartments, among other morphology transformations. We characterize the dynamics of these processes and observe a separation of time scales between the osmotic shock absorption and the shape relaxation. Our work consequently provides an insight into the dynamics of compartmentalization in vesicular systems as a result of osmotic shocks, which can be of interest in the context of early proto-cell development and proto-cell compartmentalisation.

“…[10,12,17] as it particlebased: it incorporates explicit molecular ingredients, their interactions and mechanics. Our simulation set-up can easily incorporate additional effects regularly found in more biologically-realistic settings, such as heterogeneity in the lipid composition [45], direct interactions between membrane proteins [46], asymmetry of the nanoparticle ligand arrangement [47], or the presence of membrane-deforming machinery [48]. We hope that our study will inspire future feedback between experimental studies of membrane-adhering components and coarse-grained simulations.…”

Section: Discussionmentioning

confidence: 98%

Characterising the Diffusion of Biological Nanoparticles on Fluid and Elastic Membranes

Debets

Janssen

2020

Preprint

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Tracing the motion of macromolecules, viruses, and nanoparticles adsorbed onto cell membranes is currently the most direct way of probing the complex dynamic interactions behind vital biological processes, including cell signalling, trafficking, and viral infection. The resulting trajectories are usually consistent with some type of anomalous diffusion, but the molecular origins behind the observed anomalous behaviour are usually not obvious. Here we use coarse-grained molecular dynamics simulations to help identify the physical mechanisms that can give rise to experimentally observed trajectories of nanoscopic objects moving on biological membranes. We find that diffusion on membranes of high fluidities typically results in normal diffusion of the adsorbed nanoparticle, irrespective of the concentration of receptors, receptor clustering, or multivalent interactions between the particle and membrane receptors. Gel-like membranes on the other hand result in anomalous diffusion of the particle, which becomes more pronounced at higher receptor concentrations. This anomalous diffusion is characterised by local particle trapping in the regions of high receptor concentrations and fast hopping between such regions. The normal diffusion is recovered in the limit where the gel membrane is saturated with receptors. We conclude that hindered receptor diffusivity can be a common reason behind the observed anomalous diffusion of viruses, vesicles, and nanoparticles adsorbed on cell and model membranes. Our results enable direct comparison with experiments and offer a new route for interpreting motility experiments on cell membranes.