Order at the Edge of the Bilayer: Membrane Remodeling at the Edge of a Planar Supported Bilayer Is Accompanied by a Localized Phase Change

2010 ◽  
Vol 132 (27) ◽  
pp. 9320-9327 ◽  
Author(s):  
Andreia M. Smith ◽  
Madhuri Vinchurkar ◽  
Niels Gronbech-Jensen ◽  
Atul N. Parikh
Keyword(s):  
Phase Change ◽  
Bilayer Membrane ◽  
Membrane Remodeling ◽  
Supported Bilayer

scholarly journals Natural channel protein inserts and functions in a completely artificial, solid-supported bilayer membrane

2013 ◽  
Vol 3 (1) ◽  
Author(s):  
Xiaoyan Zhang ◽  
Wangyang Fu ◽  
Cornelia G. Palivan ◽  
Wolfgang Meier
Keyword(s):  
Bilayer Membrane ◽  
Channel Protein ◽  
Supported Bilayer ◽  
Natural Channel

scholarly journals Quantitative analysis of membrane-mediated interactions and aggregation of flexible peripheral proteins orchestrating large-scale membrane remodeling

2021 ◽  
Author(s):  
Mohsen Sadeghi ◽  
Frank Noe
Keyword(s):  
Protein Interactions ◽  
Large Scale ◽  
Effective Interaction ◽  
Bilayer Membrane ◽  
Coarse Grained ◽  
Membrane Remodeling ◽  
Coarse Grained Model ◽  
Sequence Of Events ◽  
Peripheral Proteins ◽  
The Stability

Shaping and remodeling of biomembranes is essential for cellular trafficking, with membrane-binding peripheral proteins playing the key role in it. Significant membrane remodeling as in endo- and exocytosis is often due to clusters or aggregates of many proteins whose interactions may be direct or mediated via the membrane. While computer simulation could be an important tool to disentangle these interactions and understand what drives cooperative protein interactions in membrane remodeling, this has so far been extremely challenging: protein-membrane systems involve time- and lengthscales that make detailed atomistic simulations impractical, while most coarse-grained models lack the degree of detail needed to resolve the dynamics and physical effect of protein and membrane flexibility. Here, we develop a coarse-grained model of the bilayer membrane bestrewed with rotationally-symmetric flexible membrane-bound proteins. We show how this model can be parameterized based on local curvatures, protein flexibility, and the in-plane dynamics of proteins. We measure the effective interaction potential for the membrane-mediated interactions between peripheral proteins. Furthermore, we investigate the kinetics, equilibrium distributions, and the free energy landscape governing the formation and break-up of protein clusters on the surface of the membrane. We demonstrate how the flexibility of the protein plays a deciding role in highly selective macroscopic aggregation behavior. Finally, we present large-scale simulations of membrane tubulation, and discuss the sequence of events and the stability of intermediates.

scholarly journals Quantitative analysis of membrane-mediated interactions and aggregation of flexible peripheral proteins orchestrating large-scale membrane remodeling

2021 ◽  
Author(s):  
Mohsen Sadeghi ◽  
Frank Noé
Keyword(s):  
Protein Interactions ◽  
Large Scale ◽  
Effective Interaction ◽  
Bilayer Membrane ◽  
Coarse Grained ◽  
Membrane Remodeling ◽  
Coarse Grained Model ◽  
Sequence Of Events ◽  
Peripheral Proteins ◽  
The Stability

Abstract Shaping and remodeling of biomembranes is essential for cellular trafficking, with membrane-binding peripheral proteins playing the key role in it. Significant membrane remodeling as in endo- and exocytosis is often due to clusters or aggregates of many proteins whose interactions may be direct or mediated via the membrane. While computer simulation could be an important tool to disentangle these interactions and understand what drives cooperative protein interactions in membrane remodeling, this has so far been extremely challenging: protein-membrane systems involve time- and lengthscales that make detailed atomistic simulations impractical, while most coarse-grained models lack the degree of detail needed to resolve the dynamics and physical effect of protein and membrane flexibility. Here, we develop a coarse-grained model of the bilayer membrane bestrewed with rotationally-symmetric flexible membrane-bound proteins. We show how this model can be parameterized based on local curvatures, protein flexibility, and the in-plane dynamics of proteins. We measure the effective interaction potential for the membrane-mediated interactions between peripheral proteins. Furthermore, we investigate the kinetics, equilibrium distributions, and the free energy landscape governing the formation and break-up of protein clusters on the surface of the membrane. We demonstrate how the flexibility of the protein plays a deciding role in highly selective macroscopic aggregation behavior. Finally, we present large-scale simulations of membrane tubulation, and discuss the sequence of events and the stability of intermediates.

Pulling on a Sphere Adhering to a Supported Bilayer Membrane

Langmuir ◽  
2000 ◽  
Vol 16 (7) ◽  
pp. 2991-2994 ◽  
Author(s):  
C. Tordeux ◽  
J.-B. Fournier
Keyword(s):  
Bilayer Membrane ◽  
Supported Bilayer

scholarly journals Key Factors Governing Initial Stages of Lipid Droplet Formation

2021 ◽  
Author(s):  
Siyoung Kim ◽  
Chenghan Li ◽  
Robert Farese ◽  
Tobias C Walther ◽  
Gregory A Voth
Keyword(s):  
Free Energy ◽  
Ostwald Ripening ◽  
Neutral Lipids ◽  
Bilayer Membrane ◽  
Potential Of Mean Force ◽  
Coarse Grained ◽  
Thermodynamic Quantities ◽  
Membrane Remodeling ◽  
Free Energy Sampling ◽  
A Minor

Lipid droplets (LDs) are neutral lipid storage organelles surrounded by a phospholipid (PL)monolayer. LD biogenesis from the endoplasmic reticulum (ER) is driven by phase separation of neutral lipids, overcoming surface tension and membrane deformation. However, the core biophysics of the initial steps of LD formation remain relatively poorly understood. Here, we use a tunable, phenomenological coarse-grained (CG) model to study triacylglycerol (TG) nucleation in a bilayer membrane. We show that PL rigidity has a strong influence on TG lensing and membrane remodeling: When membrane rigidity increases, TG clusters remain more planar with high anisotropy but a minor degree of phase nucleation. This finding is confirmed by free energy sampling simulations that calculate the potential of mean force (PMF) as a function of the degree of nucleation and anisotropy. We also show that asymmetric tension, controlled by the number of PLs on each membrane leaflet, determines the budding direction. A TG lens buds in the direction of the monolayer containing excess PLs to allow for better PL coverage of TG, consistent with reported experiments. Finally, two governing mechanisms of the LD growth, Ostwald ripening and merging, are observed. Taken together, this study characterizes the interplay between two thermodynamic quantities during the initial LD phases, the TG bulk free energy and membrane remodeling energy.

The effect of an aluminum heat-sink layer on the laser-induced amorphization of SiOx/TeGeSn/SiOx phase-change recording films

1989 ◽  
Vol 47 ◽  
pp. 574-575
Author(s):  
Matthew R. Libera ◽  
Martin Chen
Keyword(s):  
Thin Film ◽  
Phase Change ◽  
Heat Sink ◽  
Multilayer Film ◽  
Glassy Phase ◽  
Film Structure ◽  
Glass Forming ◽  
Active Storage ◽  
Dielectric Layers ◽  
Amorphous States

Phase-change erasable optical storage is based on the ability to switch a micron-sized region of a thin film between the crystalline and amorphous states using a diffraction-limited laser as a heat source. A bit of information can be represented as an amorphous spot on a crystalline background, and the two states can be optically identified by their different reflectivities. In a typical multilayer thin-film structure the active (storage) layer is sandwiched between one or more dielectric layers. The dielectric layers provide physical containment and act as a heat sink. A viable phase-change medium must be able to quench to the glassy phase after melting, and this requires proper tailoring of the thermal properties of the multilayer film. The present research studies one particular multilayer structure and shows the effect of an additional aluminum layer on the glass-forming ability.

Crystallization fractionation technology for paraffin-based phase change materials production

2020 ◽  
pp. 33-38
Author(s):  
S.S. Kruglov (Jr.) ◽  
◽  
G.L. Patashnikov ◽  
S.S. Kruglov (Sr.) ◽  
◽  
...  
Keyword(s):  
Phase Change ◽  
Phase Change Materials
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