Relationship between water permeation and flip-flop motion in a bilayer membrane

2018 ◽  
Vol 20 (44) ◽  
pp. 28155-28161 ◽  
Author(s):  
Takuya Inokuchi ◽  
Noriyoshi Arai
Keyword(s):  
Lipid Membrane ◽  
Bilayer Membrane ◽  
Flip Flop ◽  
Water Permeation

We have investigated the effect of the flip-flop motion on the water permeation into the lipid membrane.

scholarly journals Fast flip–flop of halogenated cobalt bis(dicarbollide) anion in a lipid bilayer membrane

2017 ◽  
Vol 19 (36) ◽  
pp. 25122-25128 ◽  
Author(s):  
Tatyana I. Rokitskaya ◽  
Irina D. Kosenko ◽  
Igor B. Sivaev ◽  
Yuri N. Antonenko ◽  
Vladimir I. Bregadze
Keyword(s):  
Lipid Bilayer ◽  
Lipid Membrane ◽  
Bilayer Membrane ◽  
Lipid Bilayer Membrane ◽  
Flip Flop

Halogenation dramatically affects the flip–flop of cobalt bis(dicarbollide) across the lipid membrane causing acceleration (Cl, Br, I) or deceleration (F).

scholarly journals Gating of a mechanosensitive channel due to cellular flows

2015 ◽  
Vol 112 (32) ◽  
pp. 9822-9827 ◽  
Author(s):  
On Shun Pak ◽  
Y.-N. Young ◽  
Gary R. Marple ◽  
Shravan Veerapaneni ◽  
Howard A. Stone
Keyword(s):  
Intracellular Transport ◽  
Lipid Membrane ◽  
Fluid Flows ◽  
Bilayer Membrane ◽  
Flow Strength ◽  
Vesicle Membrane ◽  
Physiological Conditions ◽  
Planar Shear ◽  
Simulation Results ◽  
Pressure Driven Flow

A multiscale continuum model is constructed for a mechanosensitive (MS) channel gated by tension in a lipid bilayer membrane under stresses due to fluid flows. We illustrate that for typical physiological conditions vesicle hydrodynamics driven by a fluid flow may render the membrane tension sufficiently large to gate a MS channel open. In particular, we focus on the dynamic opening/closing of a MS channel in a vesicle membrane under a planar shear flow and a pressure-driven flow across a constriction channel. Our modeling and numerical simulation results quantify the critical flow strength or flow channel geometry for intracellular transport through a MS channel. In particular, we determine the percentage of MS channels that are open or closed as a function of the relevant measure of flow strength. The modeling and simulation results imply that for fluid flows that are physiologically relevant and realizable in microfluidic configurations stress-induced intracellular transport across the lipid membrane can be achieved by the gating of reconstituted MS channels, which can be useful for designing drug delivery in medical therapy and understanding complicated mechanotransduction.

scholarly journals The Flip-Flop Diffusion Mechanism across Lipids in a Hybrid Bilayer Membrane

2016 ◽  
Vol 110 (11) ◽  
pp. 2451-2462 ◽  
Author(s):  
Christopher J. Barile ◽  
Edmund C.M. Tse ◽  
Ying Li ◽  
John P. Gewargis ◽  
Nicholas A. Kirchschlager ◽  
...  
Keyword(s):  
Diffusion Mechanism ◽  
Bilayer Membrane ◽  
Flip Flop

Phospholipid Scrambling by G Protein–Coupled Receptors

2021 ◽  
Vol 51 (1) ◽  
Author(s):  
George Khelashvili ◽  
Anant K. Menon
Keyword(s):  
G Protein ◽  
Conformational Changes ◽  
Credit Card ◽  
Lipid Membrane ◽  
G Protein Coupled Receptors ◽  
Annual Review ◽  
Publication Date ◽  
Flip Flop ◽  
G Protein Coupled

Rapid flip-flop of phospholipids across the two leaflets of biological membranes is crucial for many aspects of cellular life. The transport proteins that facilitate this process are classified as pump-like flippases and floppases and channel-like scramblases. Unexpectedly, Class A G protein–coupled receptors (GPCRs), a large class of signaling proteins exemplified by the visual receptor rhodopsin and its apoprotein opsin, are constitutively active as scramblases in vitro. In liposomes, opsin scrambles lipids at a unitary rate of >100,000 per second. Atomistic molecular dynamics simulations of opsin in a lipid membrane reveal conformational transitions that expose a polar groove between transmembrane helices 6 and 7. This groove enables transbilayer lipid movement, conceptualized as the swiping of a credit card (lipid) through a card reader (GPCR). Conformational changes that facilitate scrambling are distinct from those associated with GPCR signaling. In this review, we discuss the physiological significance of GPCR scramblase activity and the modes of its regulation in cells. Expected final online publication date for the Annual Review of Biophysics, Volume 51 is May 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

scholarly journals Investigation of Fusion between Nanosized Lipid Vesicles and a Lipid Monolayer Toward Formation of Giant Lipid Vesicles with Various Kinds of Biomolecules

Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 133
Author(s):  
Koki Kamiya ◽  
Chika Arisaka ◽  
Masato Suzuki
Keyword(s):  
Lipid Droplets ◽  
Lipid Membrane ◽  
Lipid Vesicles ◽  
Cationic Lipids ◽  
Lipid Monolayer ◽  
Fusion Method ◽  
Flip Flop ◽  
Artificial Cell ◽  
Large Unilamellar Vesicles ◽  
Anionic Lipids

We determined the properties of fusion between large unilamellar vesicles (LUVs) and the lipid monolayer by measuring the fluorescence intensity of rhodamine-conjugated phospholipids in cell-sized lipid vesicles. The charge of LUVs (containing cationic lipids) and lipid droplets (containing anionic lipids) promoted lipid membrane fusion. We also investigated the formation of cell-sized lipid vesicles with asymmetric lipid distribution using this fusion method. Moreover, cell-sized asymmetric ganglioside vesicles can be generated from the planar lipid bilayer formed at the interface between the lipid droplets with/without LUVs containing ganglioside. The flip-flop dynamics of ganglioside were observed on the asymmetric ganglioside vesicles. This fusion method can be used to form asymmetric lipid vesicles with poor solubility in n-decane or lipid vesicles containing various types of membrane proteins for the development of complex artificial cell models.

Surface Plasmon Resonance Spectroscopic Study on Pore-Forming Behavior of Streptolysin O on Supported Phospholipid Bilayers

2003 ◽  
Vol 774 ◽  
Author(s):  
Thomas Wilkop ◽  
Danke Xu ◽  
Quan Cheng
Keyword(s):  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Lipid Membrane ◽  
Bilayer Membrane ◽  
Membrane Properties ◽  
Toxin Binding ◽  
Streptolysin O ◽  
Spacer Layer ◽  
Biomimetic Membrane

AbstractA novel supported bilayer membrane was formed on top of a hydrophobic spacer layer of hexyl thioctate (HT) and its application in the detection of pore forming toxins was demonstrated. The formation kinetics, effect of different flow rates on the fusion process of vesicles and perforation by incubation with streptolysin O (SLO) and pristine membranes were investigated. Individual layers of the multilayer structure were successfully characterized with surface plasmon resonance (SPR), and the resulting spectra were analyzed in order to determine the layer thickness and other membrane properties. The interaction of SLO with the pristine biomimetic membrane resulted in a pronounced change in the reflectivity spectrum. Elements of these spectral changes were analyzed to explain the process of toxin binding and pore formation taking place on the lipid membrane.

Synthetic meroterpenoids based on terpene alcohols: synthesis, self-assembly, and membranotropic properties

2020 ◽  
Vol 63 (7) ◽  
pp. 11-18
Author(s):  
Alan A. Akhmedov ◽  
◽  
Dmitriy N. Shurpik ◽  
Zainab R. Latypova ◽  
Rustem R. Gamirov ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Aqueous Solutions ◽  
Self Assembly ◽  
Lipid Membrane ◽  
Bilayer Membrane ◽  
Water Soluble ◽  
Polar Component ◽  
Terpene Alcohols ◽  
Archaeal Lipids ◽  
Pharmacologically Active

Currently, targeted drug delivery is of great interest in the field of medicine. The study of compounds capable of permeating cell membranes is a major problem in this area. The synthesis of pharmacologically active compounds includes the formation of structures with various combinations of pharmacophore fragments and properties. Amphiphilic compounds tend to exhibit membranotropic activity. From this point of view, the modification of natural products, especially terpenoids, is of particular interest. Terpenoid structures are used as membrane anchors in the development of modulators for membrane-integrated proteins or structures for creating nanocontainers. In this paper we synthesized a number of water-soluble amphiphilic meroterpenoids containing a charged pyridinium fragment on the basis of acyclic terpene alcohols. Residue of terpene alcohols – geraniol (monoterpenol), farnesol (sesquiterpenol), and phytol (diterpenol) – were used as the hydrophobic part of the amphiphilic structure. Linear acyclic alcohols are commercially available reagents and have a structure similar to that of polyprenols in archaeal lipids, which made it possible to obtain synthetic lipid-like meroterpenoids capable of self-assembly in aqueous solutions. The charged pyridinium fragment, which is included in numerous natural compounds, was of interest as a polar component. This meroterpenoids are synthetic analogs of archaeal lipids. It was shown that the studied meroterpenoids form nanosized aggregates in aqueous solutions by the method of dynamic light scattering and the Doppler microelectrophoresis method. Turbidimetric titration on model dipalmitoylphosphatidylcholine vesicles revealed that the synthesized compounds are embedded into the bilayer membrane without destroying it. Self-assembled aggregates of synthesized compounds in water can find application for drug delivery – in the creation of nanocontainers containing membrane anchors capable of interacting with the outer surface of the cell (lipid membrane).

A Molecular Dynamics Simulation Study on the Effect of Methanol on the Structural Characteristics of Lipid Bilayers

2005 ◽  
Author(s):  
Dinesh Pinisetty ◽  
Dorel Moldovan ◽  
Ram Devireddy
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Lipid Bilayers ◽  
Structural Characteristics ◽  
Fluid Phase ◽  
Md Simulations ◽  
Bilayer Membrane ◽  
Dynamics Simulation ◽  
Equilibrium Conditions ◽  
Water Permeation

To further our understanding on the water permeation process through a lipid bilayer membrane in the presence of a commonly used cryoprotective agent (methanol), we performed detailed molecular dynamics simulation (MD) studies. The MD simulations analyzed the influence of methanol (12 mol %) on the structure of a fully hydrated dipalmitoylphosphatidylcholine (DPPC) in the fluid phase and under equilibrium conditions at 323K.

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