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From vesicles to protocells: the roles of amphiphilic molecules.

Sakuma Y, Imai M - Life (Basel) (2015)

Bottom Line: It is very challenging to construct protocells from molecular assemblies.Here, we show that simple binary phospholipid vesicles have the potential to reproduce the relevant functions of adhesion, pore formation and self-reproduction of vesicles, by coupling the lipid geometries (spontaneous curvatures) and the phase separation.This achievement will elucidate the pathway from molecular assembly to cellular life.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics, Tohoku University, Aoba, Sendai 980-8578, Japan. sakuma@bio.phys.tohoku.ac.jp.

ABSTRACT
It is very challenging to construct protocells from molecular assemblies. An important step in this challenge is the achievement of vesicle dynamics that are relevant to cellular functions, such as membrane trafficking and self-reproduction, using amphiphilic molecules. Soft matter physics will play an important role in the development of vesicles that have these functions. Here, we show that simple binary phospholipid vesicles have the potential to reproduce the relevant functions of adhesion, pore formation and self-reproduction of vesicles, by coupling the lipid geometries (spontaneous curvatures) and the phase separation. This achievement will elucidate the pathway from molecular assembly to cellular life.

No MeSH data available.


Related in: MedlinePlus

Shape deformation pathways of the one-phase giant unilamellar vesicles (GUVs) under a constant osmotic pressure difference (taken from [8]).
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life-05-00651-f001: Shape deformation pathways of the one-phase giant unilamellar vesicles (GUVs) under a constant osmotic pressure difference (taken from [8]).

Mentions: The shape of the assembly is determined by the geometry of the amphiphilic molecule [3]. Molecules that have a cylindrical shape prefer to form flat bilayers. To avoid direct contact between water and the edge of the bilayer, the bilayer forms a closed membrane, i.e., a vesicle. A unique feature is that vesicle shape can be modulated by changing the external conditions. For example, when solute is added to the external medium, the vesicle exhibits a parade of shape transitions through the excess area produced by the osmotic pressure difference. The shape deformation pathways of the one-phase giant unilamellar vesicles (GUVs) under a constant osmotic pressure difference are shown in Figure 1 [7,8]. By adding solute, the shape of spherical GUV starts to fluctuate and then transforms to prolate or discocyte [9]. A further increase in the excess area causes bifurcations from prolate (discocyte) shapes to tubes (stomatocyte shape) and pears (starfish). The observed shape deformations are well described by the area difference elasticity (ADE) theory [10,11,12]. In the ADE theory, the vesicle shape is determined from the minimization of the total elastic energy, Ft, given by:


From vesicles to protocells: the roles of amphiphilic molecules.

Sakuma Y, Imai M - Life (Basel) (2015)

Shape deformation pathways of the one-phase giant unilamellar vesicles (GUVs) under a constant osmotic pressure difference (taken from [8]).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4390873&req=5

life-05-00651-f001: Shape deformation pathways of the one-phase giant unilamellar vesicles (GUVs) under a constant osmotic pressure difference (taken from [8]).
Mentions: The shape of the assembly is determined by the geometry of the amphiphilic molecule [3]. Molecules that have a cylindrical shape prefer to form flat bilayers. To avoid direct contact between water and the edge of the bilayer, the bilayer forms a closed membrane, i.e., a vesicle. A unique feature is that vesicle shape can be modulated by changing the external conditions. For example, when solute is added to the external medium, the vesicle exhibits a parade of shape transitions through the excess area produced by the osmotic pressure difference. The shape deformation pathways of the one-phase giant unilamellar vesicles (GUVs) under a constant osmotic pressure difference are shown in Figure 1 [7,8]. By adding solute, the shape of spherical GUV starts to fluctuate and then transforms to prolate or discocyte [9]. A further increase in the excess area causes bifurcations from prolate (discocyte) shapes to tubes (stomatocyte shape) and pears (starfish). The observed shape deformations are well described by the area difference elasticity (ADE) theory [10,11,12]. In the ADE theory, the vesicle shape is determined from the minimization of the total elastic energy, Ft, given by:

Bottom Line: It is very challenging to construct protocells from molecular assemblies.Here, we show that simple binary phospholipid vesicles have the potential to reproduce the relevant functions of adhesion, pore formation and self-reproduction of vesicles, by coupling the lipid geometries (spontaneous curvatures) and the phase separation.This achievement will elucidate the pathway from molecular assembly to cellular life.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics, Tohoku University, Aoba, Sendai 980-8578, Japan. sakuma@bio.phys.tohoku.ac.jp.

ABSTRACT
It is very challenging to construct protocells from molecular assemblies. An important step in this challenge is the achievement of vesicle dynamics that are relevant to cellular functions, such as membrane trafficking and self-reproduction, using amphiphilic molecules. Soft matter physics will play an important role in the development of vesicles that have these functions. Here, we show that simple binary phospholipid vesicles have the potential to reproduce the relevant functions of adhesion, pore formation and self-reproduction of vesicles, by coupling the lipid geometries (spontaneous curvatures) and the phase separation. This achievement will elucidate the pathway from molecular assembly to cellular life.

No MeSH data available.


Related in: MedlinePlus