scholarly journals A large, square-shaped, DNA origami nanopore with sealing function on a giant vesicle membrane

2021 ◽  
Author(s):  
Shoji Iwabuchi ◽  
Ibuki Kawamata ◽  
Satoshi Murata ◽  
Shin-ichiro M. Nomura

DNA origami nanopore with large size of a 10 nm square, equipping a tunable lid, enables size-selective molecular transportation through the lipid membrane of giant vesicle.

2020 ◽  
Author(s):  
Shoji Iwabuchi ◽  
Ibuki Kawamata ◽  
Satoshi Murata ◽  
Shin-ichiro Nomura

Here, we report on the design and function of a membrane nanopore through a DNA origami square tube with a cross-section of 100 nm2 . When the nanopore is added onto the giant vesicle membrane, the permeation of hydrophilic fluorescent molecules was observed. It can be sealed by the existence of the four specific single strand DNAs. A controllable artificial nanopore should help to communicate the vesicle components with their environment


2020 ◽  
Author(s):  
Shoji Iwabuchi ◽  
Ibuki Kawamata ◽  
Satoshi Murata ◽  
Shin-ichiro Nomura

Here, we report on the design and function of a membrane nanopore through a DNA origami square tube with a cross-section of 100 nm2 . When the nanopore is added onto the giant vesicle membrane, the permeation of hydrophilic fluorescent molecules was observed. It can be sealed by the existence of the four specific single strand DNAs. A controllable artificial nanopore should help to communicate the vesicle components with their environment


1989 ◽  
Vol 93 (2) ◽  
pp. 201-210 ◽  
Author(s):  
F S Cohen ◽  
W D Niles ◽  
M H Akabas

Phospholipid vesicles fuse with a planar membrane when they are osmotically swollen. Channels in the vesicle membrane are required for swelling to occur when the vesicle-containing compartment is made hyperosmotic by adding a solute (termed an osmoticant). We have studied fusion using two different channels, porin, a highly permeable channel, and nystatin, a much less permeable channel. We report that an osmoticant's ability to support fusion (defined as the magnitude of osmotic gradient necessary to obtain sustained fusion) depends on both its permeability through lipid bilayer as well as its permeability through the channel by which it enters the vesicle interior. With porin as the channel, formamide requires an osmotic gradient about ten times that required with urea, which is approximately 1/40th as permeant as formamide through bare lipid membrane. When nystatin is the channel, however, fusion rates sustained by osmotic gradients of formamide are within a factor of two of those obtained with urea. Vesicles containing a porin-impermeant solute can be induced to swell and fuse with a planar membrane when the impermeant bathing the vesicles is replaced by an isosmotic quantity of a porin-permeant solute. With this method of swelling, formamide is as effective as urea in obtaining fusion. In addition, we report that binding of vesicles to the planar membrane does not make the contact region more permeable to the osmoticant than is bare lipid bilayer. In the companion paper, we quantitatively account for the observation that the ability of a solute to promote fusion depends on its permeability properties and the method of swelling. We show that the intravesicular pressure developed drives fusion.


2015 ◽  
Vol 112 (32) ◽  
pp. 9822-9827 ◽  
Author(s):  
On Shun Pak ◽  
Y.-N. Young ◽  
Gary R. Marple ◽  
Shravan Veerapaneni ◽  
Howard A. Stone

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.


2019 ◽  
Author(s):  
Chuchu Wang ◽  
Jia Tu ◽  
Shengnan Zhang ◽  
Bin Cai ◽  
Zhenying Liu ◽  
...  

SummaryVesicle associated membrane protein 2 (VAMP2) contains a conserved SNARE motif that forms helix bundles with the homologous motifs of syntaxin-1 and SNAP25 to assemble into a SNARE complex for the exocytosis of synaptic vesicles (SV). Prior to SNARE assembly, the structure of VAMP2 is unclear. Here, using in-cell NMR spectroscopy, we described the dynamic membrane association of VAMP2 SNARE motif in mammalian cells at atomic resolution, and further tracked the intracellular structural changes of VAMP2 upon the lipid environmental changes. The underlying mechanistic basis was then investigated by solution NMR combined with mass-spectrometry-based lipidomic profiling. We analyzed the lipid compositions of lipid-raft and non-raft phases of SV membrane and revealed that VAMP2 configures distinctive conformations in different phases of SV membrane. The phase of cholesterol-rich lipid rafts could largely weaken the association of SNARE motif with SV membrane and thus, facilitate vesicle docking; While in the non-raft phase, the SNARE motif tends to hibernate on SV membrane with minor activity. Our work provides a spatial regulation of different lipid membrane phases to the structure of core SNARE proteins, which deepens our knowledge on the modulation of SNARE machinery.


2005 ◽  
Vol 230 (5) ◽  
pp. 307-319 ◽  
Author(s):  
Bhanu P. Jena

Secretion occurs in all living cells and involves the delivery of intracellular products to the cell exterior. Secretory products are Packaged and stored in membranous sacs or vesicles within the cell. When the cell needs to secrete these products, the secretory vesicles containing them dock and fuse at plasma membrane-associated supramolecular structures, called poro-somes, to release their contents. Specialized cells for neurotransmission, enzyme secretion, or hormone release use a highly regulated secretory process. Similar to other fundamen-tal cellular processes, cell secretion is precisely regulated. During secretion, swelling of secretory vesicles results in a build-up of intravesicular pressure, allowing expulsion of vesicular contents. The extent of vesicle swelling dictates the amount of vesicular contents expelled. The discovery of the Porosome as the universal secretory machinery, its isolation, its structure and dynamics at nanometer resolution and in real time, and its biochemical composition and functional reconstitution into artificial lipid membrane have been determined. The Molecular mechanism of secretory vesicle swelling and the fusion of opposing bilayers, that is, the fusion of secretory vesicle membrane at the base of the porosome membrane, have also been resolved. These findings reveal, for the first time, the universal molecular machinery and mechanism of secretion in cells.


Soft Matter ◽  
2007 ◽  
Vol 3 (7) ◽  
pp. 844-851 ◽  
Author(s):  
Cyrille Vézy ◽  
Gladys Massiera ◽  
Annie Viallat

2015 ◽  
Vol 54 (22) ◽  
pp. 6501-6505 ◽  
Author(s):  
Aleksander Czogalla ◽  
Dominik J. Kauert ◽  
Henri G. Franquelim ◽  
Veselina Uzunova ◽  
Yixin Zhang ◽  
...  

Author(s):  
Alessio Fragasso ◽  
Nicola De Franceschi ◽  
Pierre Stömmer ◽  
Eli O. van der Sluis ◽  
Hendrik Dietz ◽  
...  

AbstractMolecular traffic across lipid membranes is a vital process in cell biology that involves specialized biological pores with a great variety of pore diameters, from fractions of a nanometer to >30 nm. Creating artificial membrane pores covering similar size and complexity will aid the understanding of transmembrane molecular transport in cells, while artificial pores are also a necessary ingredient for synthetic cells. Here, we report the construction of DNA origami nanopores that have an inner diameter as large as 30 nm. We developed new methods to successfully insert these ultrawide pores into the lipid membrane of giant unilamellar vesicles (GUVs) by administering the pores concomitantly with vesicle formation in an inverted-emulsion cDICE technique. The reconstituted pores permit the transmembrane diffusion of large macromolecules such as folded proteins, which demonstrates the formation of large membrane-spanning open pores. The pores are size selective as dextran molecules with a diameter up to 22 nm can traverse the pores, whereas larger dextran molecules are blocked. By FRAP measurements and modelling of the GFP influx rate, we find that up to hundreds of pores can be functionally reconstituted into a single GUV. Our technique bears great potential for applications across different fields from biomimetics, synthetic biology, to drug delivery.


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