Osmotic pressure-induced pores in phospholipid vesicles

Taupin, C.; Dvolaïtzky, M.; Sauterey, C.

doi:10.1021/bi00692a032

Cited by 270 publications

(202 citation statements)

References 10 publications

Supporting

Mentioning

190

Contrasting

Order By: Relevance

“…In turn, this induces a lateral tension in the plasma membrane or lipid membrane, and this tension plays various important roles in the physiological functions and physicochemical properties of the membrane (1)(2)(3)(4). When the tension reaches a critical magnitude, pore formation occurs, causing lysis (rupture) of the vesicles which induces leakage (efflux) of their internal contents (5,6). The P-induced increase of vesicle volume was used to investigate the elastic properties of lipid bilayers of large unilamellar vesicles (LUVs) by measuring the change of average diameters of the LUVs under P using dynamic light scattering (DLS) (7)(8)(9).…”

Section: Introductionmentioning

confidence: 99%

Experimental Estimation of Membrane Tension Induced by Osmotic Pressure

Shibly

Ghatak

Karal

et al. 2016

Biophysical Journal

View full text Add to dashboard Cite

Osmotic pressure (P) induces the stretching of plasma membranes of cells or lipid membranes of vesicles, which plays various roles in physiological functions. However, there have been no experimental estimations of the membrane tension of vesicles upon exposure to P. In this report, we estimated experimentally the lateral tension of the membranes of giant unilamellar vesicles (GUVs) when they were transferred into a hypotonic solution. First, we investigated the effect of P on the rate constant, k p , of constant-tension (s ex )-induced rupture of dioleoylphosphatidylcholine (DOPC)-GUVs using the method developed by us recently. We obtained the s ex dependence of k p in GUVs under P and by comparing this result with that in the absence of P, we estimated the tension of the membrane due to P at the swelling equilibrium, s eq osm . Next, we measured the volume change of DOPC-GUVs under small P. The experimentally obtained values of s eq osm and the volume change agreed with their theoretical values within the limits of the experimental errors. Finally, we investigated the characteristics of the P-induced pore formation in GUVs. The s eq osm corresponding to the threshold P at which pore formation is induced is similar to the threshold tension of the s ex -induced rupture. The time course of the radius change of GUVs in the P-induced pore formation depends on the total membrane tension, s t ; for small s t , the radius increased with time to an equilibrium one, which remained constant for a long time until pore formation, but for large s t , the radius increased with time and pore formation occurred before the swelling equilibrium was reached. Based on these results, we discussed the s eq osm and the P-induced pore formation in lipid membranes.

show abstract

Section: Introductionmentioning

confidence: 99%

Experimental Estimation of Membrane Tension Induced by Osmotic Pressure

Shibly

Ghatak

Karal

et al. 2016

Biophysical Journal

View full text Add to dashboard Cite

show abstract

“…4). In that case, exchanges through the membrane were facilitated by the spontaneous formation of nanopores due to the osmotic pressure (46). Although many problems remain to be solved, efficient cell-free expression inside synthetic phospholipid vesicles was a major step in the constructive approach to artificial cells.…”

Section: Bottom-up Development Of An Artificial Cell: Broad Consideramentioning

confidence: 99%

Development of an artificial cell, from self-organization to computation and self-reproduction

Noireaux¹,

Maeda

Libchaber

2011

Proc. Natl. Acad. Sci. U.S.A.

297

267

View full text Add to dashboard Cite

This article describes the state and the development of an artificial cell project. We discuss the experimental constraints to synthesize the most elementary cell-sized compartment that can self-reproduce using synthetic genetic information. The original idea was to program a phospholipid vesicle with DNA. Based on this idea, it was shown that in vitro gene expression could be carried out inside cell-sized synthetic vesicles. It was also shown that a couple of genes could be expressed for a few days inside the vesicles once the exchanges of nutrients with the outside environment were adequately introduced. The development of a cell-free transcription/translation toolbox allows the expression of a large number of genes with multiple transcription factors. As a result, the development of a synthetic DNA program is becoming one of the main hurdles. We discuss the various possibilities to enrich and to replicate this program. Defining a program for self-reproduction remains a difficult question as nongenetic processes, such as molecular self-organization, play an essential and complementary role. The synthesis of a stable compartment with an active interface, one of the critical bottlenecks in the synthesis of artificial cell, depends on the properties of phospholipid membranes. The problem of a self-replicating artificial cell is a long-lasting goal that might imply evolution experiments.Defining Life Since Schrödinger's classic book What Is Life? (1), the definition of life has always been a puzzle with a variety of partial answers, none really satisfying. One answer is that life is a coded system with mutation and error correction (2). The information is encoded into DNA (the genotype) and the genetic code allows translating this information into proteins (the phenotype). The genetic code is universal, and the genome can support mutations, recombination, duplication, and partial transfer from organisms to organisms. Error correction limits the risk of melting the information into random sequences. This is fine, but life is also metabolism with a permanent absorption and transformation of nutrients from the environment (3). A constant flux of energy is needed to sustain the operation of this living dynamical system out of equilibrium. But life is also self-reproduction (4). Cells originate from preexisting cells by cell division. The DNA genome is replicated, the cell self-reproduces as well as the complete organism. Is self-reproduction a constraint of evolution present at each step and imposing severe design constraints or a possible definition of life? Or is life an emerging phenomenon resulting from complex chemical reactions, developing networks and cycles until, at a certain critical size of this network, life starts as an emerging property (5)? Within this approach, life is a dynamical system where signal to noise is just marginal; a living system positions itself at the edge of chaos. Finally the only generally accepted theme is that life is the result of evolution, natural selection, and adaptation (6), a...

show abstract

“…Giant unilamellar vesicles (GUVs) composed of lipid membranes have been used to elucidate the kinetics and mechanism of tension-induced pore formation. [1][2][3][4][5][6] The classical theory of tension-induced pore formation 7,8 was based on the theory of how soap films rupture. 9 According to the classical theory, once a pre-pore with radius r is formed in the membrane, the total free energy of the system changes by an additional free energy component (called the free energy of a pre-pore U(r, σ)) consisting of two terms: one term (−πr 2 σ) associated with lateral tension (σ), favoring expansion of the pre-pore, and the other term (2πrΓ) associated with the line tension (Γ) of the pre-pore edge, favoring pre-pore closure.…”

Section: Introductionmentioning

confidence: 99%

Communication: Activation energy of tension-induced pore formation in lipid membranes

Karal

Yamazaki

2015

The Journal of Chemical Physics

View full text Add to dashboard Cite

Tension plays a vital role in pore formation in biomembranes, but the mechanism of pore formation remains unclear. We investigated the temperature dependence of the rate constant of constant tension (σ)-induced pore formation in giant unilamellar vesicles of lipid membranes using an experimental method we developed. By analyzing this result, we determined the activation energy (U a ) of tensioninduced pore formation as a function of tension. A constant (U 0 ) that does not depend on tension was found to contribute significantly to U a . Analysis of the activation energy clearly indicated that the dependence of U a on σ in the classical theory is correct, but that the classical theory of pore formation is not entirely correct due to the presence of U 0 . We can reasonably consider that U 0 is a nucleation free energy to form a hydrophilic pre-pore from a hydrophobic pre-pore or a region with lower lateral lipid density. After obtaining U 0 , the evolution of a pre-pore follows a classical theory. Our data provide valuable information that help explain the mechanism of tension-induced pore formation in biomembranes and lipid membranes. C 2015 AIP Publishing LLC. [http://dx

show abstract

Osmotic pressure-induced pores in phospholipid vesicles

Cited by 270 publications

References 10 publications

Experimental Estimation of Membrane Tension Induced by Osmotic Pressure

Experimental Estimation of Membrane Tension Induced by Osmotic Pressure

Development of an artificial cell, from self-organization to computation and self-reproduction

Communication: Activation energy of tension-induced pore formation in lipid membranes

Contact Info

Product

Resources

About