The Membrane Bending Modulus in Experiments and Simulations

2016 ◽  
pp. 117-143 ◽  
Author(s):  
D. Bochicchio ◽  
L. Monticelli
Keyword(s):  
Bending Modulus ◽  
Membrane Bending

scholarly journals Estimation of membrane bending modulus of stiffness tuned human red blood cells from micropore filtration studies

PLoS ONE ◽  
2019 ◽  
Vol 14 (12) ◽  
pp. e0226640 ◽  
Author(s):  
Rekha Selvan ◽  
Praveen Parthasarathi ◽  
Shruthi S. Iyengar ◽  
Sharath Ananthamurthy ◽  
Sarbari Bhattacharya
Keyword(s):  
Red Blood Cells ◽  
Blood Cells ◽  
Human Red Blood Cells ◽  
Bending Modulus ◽  
Membrane Bending

scholarly journals Physical Characterization of Triolein and Implications for Its Role in Lipid Droplet Biogenesis

2021 ◽  
Author(s):  
Siyoung Kim ◽  
Gregory A. Voth
Keyword(s):  
Negative Curvature ◽  
Critical Concentration ◽  
Bilayer Membrane ◽  
The Other ◽  
Coarse Grained ◽  
Membrane Properties ◽  
Bending Modulus ◽  
Cytosolic Side ◽  
Membrane Bending ◽  
Free Energy Sampling

Lipid droplets (LDs) are neutral lipid storing organelles surrounded by a phospholipid (PL) monolayer. At present, how LDs are formed in the endoplasmic reticulum (ER) bilayer is poorly understood. In this study, we present a revised triolein (TG) model, the main constituent of the LD core, and characterize its properties in a bilayer membrane to demonstrate the implications of its behavior in LD biogenesis. In all-atom (AA) bilayer simulations, TG resides at the surface, adopting PL-like conformations (denoted in this work as SURF-TG). Free energy sampling simulation results estimate the barrier for TG relocating from the bilayer surface to the bilayer center to be ~2 kcal/mol in the absence of an oil lens. Conical SURF-TG is able to modulate membrane properties by increasing PL ordering, decreasing bending modulus, and creating local negative curvature. The other conical lipid, dioleoyl-glycerol (DAG), also reduces the membrane bending modulus and populates the negative curvature regions. A phenomenological coarse-grained (CG) model is also developed to observe larger scale SURF-TG-mediated membrane deformation. The CG simulations confirm that TG nucleates between the bilayer leaflets at a critical concentration when SURF-TG is evenly distributed. However, when one monolayer contains more SURF-TG, the membrane bends toward the other leaflet. The central conclusion of this study is that SURF-TG is a negative curvature inducer, as well as a membrane modulator. To this end, a model has proposed in which the accumulation of SURF-TG in the luminal leaflet bends the ER bilayer toward the cytosolic side, followed by TG nucleation.

scholarly journals Correction: Estimation of membrane bending modulus of stiffness tuned human red blood cells from micropore filtration studies

PLoS ONE ◽  
2020 ◽  
Vol 15 (1) ◽  
pp. e0228125
Author(s):  
Rekha Selvan ◽  
Praveen Parthasarathi ◽  
Shruthi S. Iyengar ◽  
Sharath Ananthamurthy ◽  
Sarbari Bhattacharya
Keyword(s):  
Red Blood Cells ◽  
Blood Cells ◽  
Human Red Blood Cells ◽  
Bending Modulus ◽  
Membrane Bending

scholarly journals Membrane Bending Modulus and Adhesion Energy of Wild-Type and Mutant Cells of Dictyostelium Lacking Talin or Cortexillins

1998 ◽  
Vol 74 (1) ◽  
pp. 514-522 ◽  
Author(s):  
Rudolf Simson ◽  
Eva Wallraff ◽  
Jan Faix ◽  
Jens Niewöhner ◽  
Günther Gerisch ◽  
...  
Keyword(s):  
Adhesion Energy ◽  
Wild Type ◽  
Bending Modulus ◽  
Membrane Bending ◽  
Mutant Cells

scholarly journals Stiffness of Fluid and Gel Phase Lipid Nanovesicles: Weighting the Contributions of Membrane Bending Modulus and Luminal Pressurization

Langmuir ◽  
2021 ◽  
Author(s):  
Andrea Ridolfi ◽  
Lucrezia Caselli ◽  
Matteo Baldoni ◽  
Costanza Montis ◽  
Francesco Mercuri ◽  
...  
Keyword(s):  
Bending Modulus ◽  
Gel Phase ◽  
Membrane Bending

scholarly journals Interleaflet coupling of n-alkane incorporated bilayers

2020 ◽  
Vol 22 (10) ◽  
pp. 5418-5426 ◽  
Author(s):  
Hatsuho Usuda ◽  
Mafumi Hishida ◽  
Elizabeth G. Kelley ◽  
Yasuhisa Yamamura ◽  
Michihiro Nagao ◽  
...  
Keyword(s):  
Bending Modulus ◽  
Membrane Bending ◽  
The Relationship

The relationship between the membrane bending modulus (κ) and compressibility modulus (KA) depends on the extent of coupling between the two monolayers (leaflets).

Living cell motility

2007 ◽  
Vol 366 (1864) ◽  
pp. 319-328 ◽  
Author(s):  
José Coelho Neto ◽  
Oscar Nassif Mesquita
Keyword(s):  
Membrane Surface ◽  
Optical Microscope ◽  
Living Cells ◽  
Physical Models ◽  
Microscopy Technique ◽  
Bending Modulus ◽  
Membrane Fluctuations ◽  
Complex Process ◽  
Dynamical Parameters ◽  
Membrane Bending

The motility of living eukaryotic cells is a complex process driven mainly by polymerization and depolymerization of actin filaments underneath the plasmatic membrane (actin cytoskeleton). However, the exact mechanisms through which cells are able to control and employ ‘actin-generated’ mechanical forces, in order to change shape and move in a well-organized and coordinated way, are not quite established. Here, we summarize the experimental results obtained by our research group during recent years in studying the motion of living cells, such as macrophages and erythrocytes. By using our recently developed defocusing microscopy technique, which allows quantitative analysis of membrane surface dynamics of living cells using a simple bright-field optical microscope, we were able to analyse morphological and dynamical parameters of membrane ruffles and small membrane fluctuations, study the process of phagocytosis and also measure values for cell refractive index, membrane bending modulus and cell viscosity. Although many questions still remain unanswered, our data seem to corroborate some aspects of recent physical models of cell membranes and motility.

scholarly journals Membrane Bending Modulus for Ternary Mixture Models of the Cell Plasma Membrane

2015 ◽  
Vol 108 (2) ◽  
pp. 241a
Author(s):  
Rebecca Simpson ◽  
David Ackerman ◽  
Gerald Feigenson
Keyword(s):  
Plasma Membrane ◽  
Mixture Models ◽  
Ternary Mixture ◽  
Cell Plasma Membrane ◽  
Bending Modulus ◽  
Cell Plasma ◽  
Membrane Bending

scholarly journals Synaptotagmin-1 and Doc2b exhibit distinct membrane remodeling mechanisms

2019 ◽  
Author(s):  
Raya Sorkin ◽  
Margherita Marchetti ◽  
Emma Logtenberg ◽  
Melissa Piontek ◽  
Emma Kerklingh ◽  
...  
Keyword(s):  
Confocal Imaging ◽  
Coupling Mechanism ◽  
Dependent Manner ◽  
Membrane Remodeling ◽  
Membrane Interactions ◽  
Bending Modulus ◽  
Symmetrical Configuration ◽  
Synaptotagmin 1 ◽  
Membrane Bending ◽  
Sensor Proteins

AbstractWhile the role of Synaptotagmin-1 in living cells has been described in detail, it remains a challenge to dissect the contribution of membrane remodelling by its two cytoplasmic C2 domains (C2AB) to the Ca2+-secretion coupling mechanism. Here, we study membrane remodeling using pairs of optically-trapped beads coated with SNARE-free synthetic membranes. We find that the soluble C2AB domain of Syt1 strongly affects the probability and strength of membrane-membrane interactions in a strictly Ca2+- and protein-dependent manner. A lipid mixing assay with confocal imaging reveals that at low Syt1 concentrations, no hemifusion is observed. Notably, for similar low concentrations of Doc2b hemifusion does occur. Consistently, both C2AB fragments cause a reduction in the membrane bending modulus, as measured by an AFM-based method. This lowering of the energy required for membrane deformation likely contributes to the overall Ca2+-secretion triggering mechanism by calcium sensor proteins. When comparing symmetrical (both sides) and asymmetrical (one side) presence of protein on the membranes, Syt1 favors an asymmetrical but Doc2b a symmetrical configuration, as inferred from higher tether probabilities and break forces. This provides support for the direct bridging hypothesis for Syt-1, while hinting to possible preference for protein-protein (and not protein-membrane) interactions for Doc2b. Overall, our study sheds new light on the mechanism of Ca2+ induced fusion triggering, which is essential for fundamental understanding of secretion of neurotransmitters and endocrine substances.

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