Lipid Bilayers as Models of Biological Membranes

BioScience ◽  
1976 ◽  
Vol 26 (7) ◽  
pp. 436-443 ◽  
Author(s):  
Stuart McLaughlin
Keyword(s):  
Lipid Bilayers ◽  
Biological Membranes

Observation of Concanavalin-A receptors on hydrated planar erythrocyte membrane film by in situ electron microscopy

1983 ◽  
Vol 41 ◽  
pp. 608-609
Author(s):  
Neng-Bo He ◽  
S.W. Hui
Keyword(s):  
Lipid Bilayers ◽  
Erythrocyte Membrane ◽  
Lipid Membranes ◽  
Surface Film ◽  
Biological Membranes ◽  
Electron Microscopic Observation ◽  
Electron Microscopic ◽  
Black Lipid Membranes ◽  
Fine Mesh ◽  
Planar Films

Monolayers and planar "black" lipid membranes have been widely used as models for studying the structure and properties of biological membranes. Because of the lack of a suitable method to prepare these membranes for electron microscopic observation, their ultrastructure is so far not well understood. A method of forming molecular bilayers over the holes of fine mesh grids was developed by Hui et al. to study hydrated and unsupported lipid bilayers by electron diffraction, and to image phase separated domains by diffraction contrast. We now adapted the method of Pattus et al. of spreading biological membranes vesicles on the air-water interfaces to reconstitute biological membranes into unsupported planar films for electron microscopic study. hemoglobin-free human erythrocyte membrane stroma was prepared by hemolysis. The membranes were spreaded at 20°C on balanced salt solution in a Langmuir trough until a surface pressure of 20 dyne/cm was reached. The surface film was repeatedly washed by passing to adjacent troughs over shallow partitions (fig. 1).

scholarly journals Fracture faces of frozen membranes: 50th anniversary

2016 ◽  
Vol 27 (3) ◽  
pp. 421-423
Author(s):  
Daniel Branton
Keyword(s):  
Electron Microscopy ◽  
Lipid Bilayers ◽  
Fracture Process ◽  
Relative Proportion ◽  
50Th Anniversary ◽  
Biological Membranes ◽  
Bilayer Membrane ◽  
Biological Cells ◽  
Membrane Surfaces ◽  
Freeze Etching

In 1961, the development of an improved freeze-etching (FE) procedure to prepare rapidly frozen biological cells or tissues for electron microscopy raised two important questions. How does a frozen cell membrane fracture? What do the extensive face views of the cell’s membranes exposed by the fracture process of FE tell us about the overall structure of biological membranes? I discovered that all frozen membranes tend to split along weakly bonded lipid bilayers. Consequently, the fracture process exposes internal membrane faces rather than either of the membrane’s two external surfaces. During etching, when ice is allowed to sublime after fracturing, limited regions of the actual membrane surfaces are revealed. Examination of the fractured faces and etched surfaces provided strong evidence that biological membranes are organized as lipid bilayers with some proteins on the surface and other proteins extending through the bilayer. Membrane splitting made it possible for electron microscopy to show the relative proportion of a membrane’s area that exists in either of these two organizational modes.

scholarly journals Non-axisymmetric shapes of biological membranes from locally induced curvature

2019 ◽  
Author(s):  
Yannick A. D. Omar ◽  
Amaresh Sahu ◽  
Roger A. Sauer ◽  
Kranthi K. Mandadapu
Keyword(s):  
Phase Separation ◽  
Cell Membrane ◽  
Viscous Flow ◽  
Lipid Bilayers ◽  
Biological Membranes ◽  
Rate Of Change ◽  
Computational Studies ◽  
Biological Processes ◽  
Resting Tension ◽  
Physical Phenomena

In various biological processes such as endocytosis and caveolae formation, the cell membrane is locally deformed into curved configurations. Previous theoretical and computational studies to understand membrane morphologies resulting from locally induced curvature are often limited to axisymmetric shapes, which severely restricts the physically admissible morphologies. Under the restriction of axisymmetry, past efforts predict that the cell membrane buds at low resting tensions and stalls at a flat pit at high resting tensions. In this work, we lift the restriction of axisymmetry by employing recent theoretical and numerical advances to understand arbitrarily curved and deforming lipid bilayers. Our non-axisymmetric morphologies reveal membrane morphologies which agree well with axisymmetric studies—however only if the resting tension of the membrane is low. When the resting tension is moderate to high, we show that (i) axisymmetric invaginations are unstable; and (ii) non-axisymmetric ridge-shaped structures are energetically favorable. We further study the dynamical effects resulting from the interplay between intramembrane viscous flow and induced curvature, and find the rate at which the locally induced curvature increases is a key determinant in the formation of ridges. In particular, we show that axisymmetric buds are favored when the induced curvature is rapidly increased, while non-axisymmetric ridges are favored when the curvature is slowly increased: The rate of change of induced curvature affects the intramembrane viscous flow of lipids, which can impede the membrane’s ability to transition into ridges. We conclude that the appearance of non-axisymmetric ridges indicates that axisymmetry cannot be generally assumed when understanding processes involving locally induced curvature. Our results hold potentially relevant implications for biological processes such as endocytosis, and physical phenomena like phase separation in lipid bilayers.

On dynamic molecular and elastic properties of lipid bilayers and biological membranes

1984 ◽  
Vol 10 ◽  
pp. 321-335 ◽  
Author(s):  
E. Sackmann ◽  
J. Engelhardt ◽  
K. Fricke ◽  
H. Gaub
Keyword(s):  
Lipid Bilayers ◽  
Elastic Properties ◽  
Biological Membranes

scholarly journals Structure and Dynamics of Glycosphingolipids in Lipid Bilayers: Insights from Molecular Dynamics Simulations

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Ronak Y. Patel ◽  
Petety V. Balaji
Keyword(s):  
Molecular Dynamics ◽  
Lipid Bilayers ◽  
Membrane Structure ◽  
Lipid Membrane ◽  
Biological Membranes ◽  
Md Simulations ◽  
Atomic Level ◽  
Structure And Dynamics ◽  
Hydrogen Bonding Interactions ◽  
Dynamics Simulations

Glycolipids are important constituents of biological membranes, and understanding their structure and dynamics in lipid bilayers provides insights into their physiological and pathological roles. Experimental techniques have provided details into their behavior at model and biological membranes; however, computer simulations are needed to gain atomic level insights. This paper summarizes the insights obtained from MD simulations into the conformational and orientational dynamics of glycosphingolipids and their exposure, hydration, and hydrogen-bonding interactions in membrane environment. The organization of glycosphingolipids in raft-like membranes and their modulation of lipid membrane structure are also reviewed.

Characterization of the fluorophore 4-heptadecyl-7-hydroxycoumarin: a probe for the head-group region of lipid bilayers and biological membranes

Biochemistry ◽  
1985 ◽  
Vol 24 (3) ◽  
pp. 573-581 ◽  
Author(s):  
Ranajit Pal ◽  
William A. Petri ◽  
Vered Ben-Yashar ◽  
Robert R. Wagner ◽  
Yechezkel Barenholz
Keyword(s):  
Lipid Bilayers ◽  
Biological Membranes ◽  
Head Group

scholarly journals A consensus segment in the M2 domain of the hP2X7 receptor shows ion channel activity in planar lipid bilayers and in biological membranes

2012 ◽  
Vol 1818 (1) ◽  
pp. 64-71 ◽  
Author(s):  
Cristina Alves Magalhães de Souza ◽  
Pedro Celso Nogueira Teixeira ◽  
Robson Xavier Faria ◽  
Oxana Krylova ◽  
Peter Pohl ◽  
...  
Keyword(s):  
Ion Channel ◽  
Lipid Bilayers ◽  
Biological Membranes ◽  
Planar Lipid Bilayers ◽  
Channel Activity

scholarly journals Assembly of Model Membrane Nanodiscs for Native Mass Spectrometry

2021 ◽  
Author(s):  
Marius Kostelic ◽  
Ciara K. Zak ◽  
Hiruni Jayasekera ◽  
Michael Marty
Keyword(s):  
Mass Spectrometry ◽  
Membrane Protein ◽  
Lipid Bilayers ◽  
Biological Membranes ◽  
Native Mass Spectrometry ◽  
Model Membrane ◽  
Peptide Interactions ◽  
Lipid Nanodiscs ◽  
Natural Lipid ◽  
Selection Of

Native mass spectrometry (MS) with nanodiscs is a promising technique for characterizing membrane protein and peptide interactions in lipid bilayers. However, prior studies have used nanodiscs made of only one or two lipids, which lack the complexity of a natural lipid bilayer. To better model specific biological membranes, we developed model mammalian, bacterial, and mitochondrial nanodiscs with up to four different phospholipids. Careful selection of lipids with similar masses that balance the fluidity and curvature enabled these complex nanodiscs to be assembled and resolved with native MS. We then applied this approach to characterize the specificity and incorporation of LL-37, a human antimicrobial peptide, in single lipid nanodiscs versus model bacterial nanodiscs. Overall, development of these model membrane nanodiscs reveals new insights into the assembly of complex nanodiscs and provides a useful toolkit for studying membrane protein, peptide, and lipid interactions in model biological membranes.

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