scholarly journals Self-Assembly of Filopodia-Like Structures on Supported Lipid Bilayers

Science ◽  
2010 ◽  
Vol 329 (5997) ◽  
pp. 1341-1345 ◽  
Author(s):  
Kwonmoo Lee ◽  
Jennifer L. Gallop ◽  
Komal Rambani ◽  
Marc W. Kirschner
Keyword(s):  
Lipid Bilayers ◽  
Self Assembly ◽  
Membrane Microdomains ◽  
Supported Lipid Bilayers ◽  
Actin Bundles ◽  
Bar Domain ◽  
Egg Extracts ◽  
Domain Protein

Filopodia are finger-like protrusive structures, containing actin bundles. By incubating frog egg extracts with supported lipid bilayers containing phosphatidylinositol 4,5 bisphosphate, we have reconstituted the assembly of filopodia-like structures (FLSs). The actin assembles into parallel bundles, and known filopodial components localize to the tip and shaft. The filopodia tip complexes self-organize—they are not templated by preexisting membrane microdomains. The F-BAR domain protein toca-1 recruits N-WASP, followed by the Arp2/3 complex and actin. Elongation proteins, Diaphanous-related formin, VASP, and fascin are recruited subsequently. Although the Arp2/3 complex is required for FLS initiation, it is not essential for elongation, which involves formins. We propose that filopodia form via clustering of Arp2/3 complex activators, self-assembly of filopodial tip complexes on the membrane, and outgrowth of actin bundles.

scholarly journals S-Layer Self-Assembly on Supported Lipid-Bilayers: The Importance of Amorphous Precursors and Folding Transitions

2010 ◽  
Vol 98 (3) ◽  
pp. 10a
Author(s):  
Sungwook Chung ◽  
Seong-Ho Shin ◽  
Stephen Whitelam ◽  
Carolyn Bertozzi ◽  
Jim De Yoreo
Keyword(s):  
Lipid Bilayers ◽  
Self Assembly ◽  
Supported Lipid Bilayers

scholarly journals On the Kinetics of Adsorption and Two-Dimensional Self-Assembly of Annexin A5 on Supported Lipid Bilayers

2005 ◽  
Vol 89 (5) ◽  
pp. 3372-3385 ◽  
Author(s):  
Ralf P. Richter ◽  
Joséphine Lai Kee Him ◽  
Béatrice Tessier ◽  
Céline Tessier ◽  
Alain R. Brisson
Keyword(s):  
Lipid Bilayers ◽  
Self Assembly ◽  
Supported Lipid Bilayers ◽  
Annexin A5 ◽  
Two Dimensional ◽  
Kinetics Of Adsorption ◽  
Kinetics Of

scholarly journals Vesicle capture by discrete self-assembled clusters of membrane-bound Munc13

2020 ◽  
Author(s):  
Feng Li ◽  
Venkat Kalyana Sundaram ◽  
Alberto T. Gatta ◽  
Jeff Coleman ◽  
Shyam S. Krishnakumar ◽  
...  
Keyword(s):  
Lipid Bilayers ◽  
Self Assembly ◽  
Synaptic Vesicles ◽  
Supported Lipid Bilayers ◽  
Membrane Domains ◽  
Vesicle Docking ◽  
Multiple Copies ◽  
Membrane Bound ◽  
Small Unilamellar Vesicles ◽  
Active Zones

ABSTRACTMunc13 is a large banana-shaped soluble protein that is involved in the regulation of synaptic vesicle docking and fusion. Recent studies suggested that multiple copies of Munc13 form nanoassemblies in active zones of neurons. However, it is not known if such clustering is an inherent self-assembly property of Munc13 or whether Munc13 clusters indirectly by multivalent binding to synaptic vesicles or specific plasma membrane domains at docking sites in the active zone. The functional significance of putative Munc13 clustering is also unknown. Here we report that nano-clustering is an inherent property of Munc13, and is indeed required for vesicle binding to bilayers containing Munc13. Pure Munc13 reconstituted onto supported lipid bilayers assembled into clusters containing from 2 to ∼20 copies as revealed by a combination of quantitative TIRF microscopy and step-wise photobleaching. Surprisingly, only clusters a minimum of 6 copies of Munc13 were capable of efficiently capturing and retaining small unilamellar vesicles. The C-terminal C2C domain of Munc13 is not required for Munc13 clustering, but is required for efficient vesicle capture.

scholarly journals Phospholipid membranes promote the early stage assembly of α-synuclein aggregates

2018 ◽  
Author(s):  
Zhengjian Lv ◽  
Mohtadin Hashemi ◽  
Siddhartha Banerjee ◽  
Karen Zagorski ◽  
Jean-Christophe Rochet ◽  
...  
Keyword(s):  
Lipid Bilayers ◽  
Self Assembly ◽  
Early Stage ◽  
Time Lapse ◽  
Supported Lipid Bilayers ◽  
Membrane Composition ◽  
Force Microscopy ◽  
Atomic Force ◽  
Nanomolar Concentration ◽  
Surface Changes

AbstractDevelopment of Parkinson’s disease is associated with spontaneous self-assembly of α-synuclein (α-syn). Efforts aimed at understanding this process have produced little clarity and the mechanism remains elusive. We report a novel effect of phospholipid bilayers on the catalysis of α-syn aggregation from monomers. We directly visualized α-syn aggregation on supported lipid bilayers using time-lapse atomic force microscopy. We discovered that α-syn assemble in aggregates on bilayer surfaces even at the nanomolar concentration of monomers in solution. The efficiency of the aggregation process depends on the membrane composition, being highest for a negatively charged bilayer. Furthermore, assembled aggregates can dissociate from the surface, suggesting that on-surface aggregation can be a mechanism by which pathological aggregates are produced. Computational modeling revealed that interaction of α-syn with bilayer surface changes the protein conformation and its affinity to assemble into dimers, and these properties depend on the bilayer composition. A model of the membrane-mediated aggregation triggering the assembly of neurotoxic aggregates is proposed.

scholarly journals Dry Two-Step Self-Assembly of Stable Supported Lipid Bilayers on Silicon Substrates

2020 ◽  
Vol 21 (18) ◽  
pp. 6819
Author(s):  
Marcelo A. Cisternas ◽  
Francisca Palacios-Coddou ◽  
Sebastian Molina ◽  
Maria Jose Retamal ◽  
Nancy Gomez-Vierling ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Lipid Bilayers ◽  
Self Assembly ◽  
Liquid Crystalline ◽  
High Vacuum ◽  
Supported Lipid Bilayers ◽  
Silicon Substrates ◽  
Long Term Stability ◽  
Assembly Method ◽  
Annealing Step

Artificial membranes are models for biological systems and are important for applications. We introduce a dry two-step self-assembly method consisting of the high-vacuum evaporation of phospholipid molecules over silicon, followed by a subsequent annealing step in air. We evaporate dipalmitoylphosphatidylcholine (DPPC) molecules over bare silicon without the use of polymer cushions or solvents. High-resolution ellipsometry and AFM temperature-dependent measurements are performed in air to detect the characteristic phase transitions of DPPC bilayers. Complementary AFM force-spectroscopy breakthrough events are induced to detect single- and multi-bilayer formation. These combined experimental methods confirm the formation of stable non-hydrated supported lipid bilayers with phase transitions gel to ripple at 311.5 ± 0.9 K, ripple to liquid crystalline at 323.8 ± 2.5 K and liquid crystalline to fluid disordered at 330.4 ± 0.9 K, consistent with such structures reported in wet environments. We find that the AFM tip induces a restructuring or intercalation of the bilayer that is strongly related to the applied tip-force. These dry supported lipid bilayers show long-term stability. These findings are relevant for the development of functional biointerfaces, specifically for fabrication of biosensors and membrane protein platforms. The observed stability is relevant in the context of lifetimes of systems protected by bilayers in dry environments.

scholarly journals Colloid supported lipid bilayers for self-assembly

Soft Matter ◽  
2019 ◽  
Vol 15 (6) ◽  
pp. 1345-1360 ◽  
Author(s):  
Melissa Rinaldin ◽  
Ruben W. Verweij ◽  
Indrani Chakraborty ◽  
Daniela J. Kraft
Keyword(s):  
Lipid Bilayers ◽  
Self Assembly ◽  
Flexible Structures ◽  
The Self ◽  
Supported Lipid Bilayers ◽  
Experimental Parameters

Careful tuning of the experimental parameters involved in preparing colloid supported lipid bilayers enables the self-assembly of flexible structures.

Bridging Across Length Scales: Multi-Scale Ordering of Supported Lipid Bilayers via Lipoprotein Self-assembly and Surface Patterning

2008 ◽  
Vol 130 (33) ◽  
pp. 11164-11169 ◽  
Author(s):  
Madhuri S. Vinchurkar ◽  
Daniel A. Bricarello ◽  
Jens O. Lagerstedt ◽  
James P. Buban ◽  
Henning Stahlberg ◽  
...  
Keyword(s):  
Lipid Bilayers ◽  
Self Assembly ◽  
Surface Patterning ◽  
Supported Lipid Bilayers ◽  
Length Scales ◽  
Multi Scale

Influence of Brain Gangliosides on the Formation and Properties of Supported Lipid Bilayers for Binding Kinetics Studies

2018 ◽  
Author(s):  
Luke Jordan ◽  
Nathan Wittenberg
Keyword(s):  
Lipid Bilayers ◽  
Binding Kinetics ◽  
Supported Lipid Bilayers ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Supported Lipid Bilayer ◽  
Head Groups ◽  
Lipid Diffusion ◽  
Kinetics Of ◽  
Brain Gangliosides

This is a comprehensive study of the effects of the four major brain gangliosides (GM1, GD1b, GD1a, and GT1b) on the adsorption and rupture of phospholipid vesicles on SiO2 surfaces for the formation of supported lipid bilayer (SLB) membranes. Using quartz crystal microbalance with dissipation monitoring (QCM-D) we show that gangliosides GD1a and GT1b significantly slow the SLB formation process, whereas GM1 and GD1b have smaller effects. This is likely due to the net ganglioside charge as well as the positions of acidic sugar groups on ganglioside glycan head groups. Data is included that shows calcium can accelerate the formation of ganglioside-rich SLBs. Using fluorescence recovery after photobleaching (FRAP) we also show that the presence of gangliosides significantly reduces lipid diffusion coefficients in SLBs in a concentration-dependent manner. Finally, using QCM-D and GD1a-rich SLB membranes we measure the binding kinetics of an anti-GD1a antibody that has similarities to a monoclonal antibody that is a hallmark of a variant of Guillain-Barre syndrome.

Sign in / Sign up

Export Citation Format

Share Document