Membrane Leaflet Dynamics
Membrane Leaflet Dynamics - Related Videos
11:12
Protocol for Relative Hydrodynamic Assessment of Tri-leaflet Polymer Valves
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Cited by 5 •
2013
There has been renewed interest in developing polymer valves. Here, the objectives are to demonstrate the feasibility of modifying a commercial pulse duplicator to accommodate tri-leaflet geometries and to define a protocol to present polymer valve hydrodynamic data in comparison to native and prosthetic valve data collected under near-identical conditions.
12:48
Measuring Near Plasma Membrane and Global Intracellular Calcium Dynamics in Astrocytes
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Cited by 16 •
2009
We describe how to measure near membrane and global intracellular calcium dynamics in cultured astrocytes using total internal reflection and epifluorescence microscopy.
10:31
A Model Membrane Platform for Reconstituting Mitochondrial Membrane Dynamics
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Cited by 4 •
2020
Mitochondrial fusion is an important homeostatic reaction underlying mitochondrial dynamics. Described here is an in vitro reconstitution system to study mitochondrial inner-membrane fusion that can resolve membrane tethering, docking, hemifusion, and pore opening. The versatility of this approach in exploring cell membrane systems is discussed.
10:01
Flash-and-Freeze: A Novel Technique to Capture Membrane Dynamics with Electron Microscopy
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Cited by 7 •
2017
We developed a novel technique in electron microscopy, "flash-and-freeze," that enables the visualization of membrane dynamics with ms temporal resolution. This technique combines the optogenetic stimulation of neurons with high-pressure freezing. Here, we demonstrate the procedures and describe the protocols in detail.
09:42
Unraveling Entropic Rate Acceleration Induced by Solvent Dynamics in Membrane Enzymes
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Cited by 17 •
2016
Channels for the transportation of water molecules in enzymes influence active site solvation and catalysis. Herein we present a protocol for the engineering of these additional catalytic motifs based on in silico computer modeling and experiments. This will enhance our understanding of the influence of solvent dynamics on enzyme catalysis.
FAQs
The hydrophobic core of a lipid bilayer presents a substantial barrier to moving polar lipid headgroups between leaflets, making spontaneous flip-flop slow. Consequently, cells depend on flippases, floppases, and scramblases to control redistribution on biologically useful timescales. This distinction explains how membranes can preserve organized asymmetry while still permitting rapid remodeling when cellular conditions change.
These protein-mediated activities regulate leaflet composition through different modes of control. Flippases and floppases use energy to drive lipid redistribution, whereas scramblases alter lipid mobility and can disrupt preexisting asymmetry. Their combined activity allows a membrane to establish, maintain, or release compositional differences between its two leaflets, linking molecular transport to larger changes in cell behavior.
Unequal lipid redistribution between the two leaflets changes the relative composition and packing of each membrane layer. Those differences can affect membrane curvature, making leaflet dynamics relevant to bending and vesicle formation. The process therefore connects molecular-scale lipid movement with membrane trafficking, where curved regions and vesicles support the organization and movement of cellular materials.
Phosphatidylserine is normally concentrated in the inner leaflet, so its appearance on the outer surface provides a detectable change in membrane organization. During apoptosis, this exposure can mark the cell for clearance. Leaflet dynamics therefore connect a physical rearrangement of membrane lipids with a biological communication signal that helps distinguish cells undergoing programmed removal.
Researchers can use leaflet behavior as a framework for examining membrane organization, cellular communication, signaling, curvature, vesicle formation, and trafficking. Changes in lipid distribution reveal how membranes respond when asymmetry is maintained or disrupted. This perspective is also useful for connecting molecular membrane events with broader outcomes, including disease mechanisms and altered cell clearance.
Understanding how lipid composition changes between leaflets helps inform the design of biomimetic membranes that reproduce selected features of biological bilayers. The same principles can guide drug-delivery systems by linking membrane organization with curvature, vesicle formation, and trafficking. Such applications use leaflet behavior as a design variable rather than treating the membrane as a static barrier.