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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

(a) Phase diagram of DPPE/DOPC binary GUV. Fluorescence micrograph images in the figures show the appearance of a vesicle at the one phase and two phase region. MDPPE is the mole fraction of DPPE. (b) Adhesion diagram of DPPE/DOPC binary GUV. Circles, crosses and triangles indicate adhesion, non-adhesion and boundary states, respectively (taken from [48]).
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life-05-00651-f013: (a) Phase diagram of DPPE/DOPC binary GUV. Fluorescence micrograph images in the figures show the appearance of a vesicle at the one phase and two phase region. MDPPE is the mole fraction of DPPE. (b) Adhesion diagram of DPPE/DOPC binary GUV. Circles, crosses and triangles indicate adhesion, non-adhesion and boundary states, respectively (taken from [48]).

Mentions: The hemifusion of GUVs induced by the inverse-cone-shaped lipid was realized using binary GUV composed of DPPE (inverse-cone-shaped lipid, Tm = 62 °C) and DOPC (cylinder-shaped lipid, Tm = −20 °C). The phase diagram is shown in Figure 13a, where the binary membrane with a DPPE mole fraction MDPPE >60% could not form GUVs due to the geometry of DPPE. Based on the phase diagram, the adhesion of the binary GUVs was examined by attaching two GUVs using a micro-manipulation technique. The obtained adhesion diagram for the DPPE/DOPC binary GUV is shown in Figure 13b, where circles indicate that the two GUVs adhere to one another in response to the contact, while cross symbols mean that the GUVs do not exhibit adhesion and triangles indicate the boundary region. The adhesion/non-adhesion boundary in Figure 13b agrees well with the immiscible boundary of the DPPE/DPPC binary vesicles in Figure 13a. In addition, when the temperature is increased so that one homogeneous phase region is present, the adhering vesicles separate spontaneously, indicating that the phase separation is responsible for the observed adhesion. A similar adhesion behavior was also confirmed for binary GUVs composed of DPhPC (inverse-cone-shaped lipid, Tm < −120 °C) and DPPC (cylinder-shaped lipid, Tm = 41 °C).


From vesicles to protocells: the roles of amphiphilic molecules.

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

(a) Phase diagram of DPPE/DOPC binary GUV. Fluorescence micrograph images in the figures show the appearance of a vesicle at the one phase and two phase region. MDPPE is the mole fraction of DPPE. (b) Adhesion diagram of DPPE/DOPC binary GUV. Circles, crosses and triangles indicate adhesion, non-adhesion and boundary states, respectively (taken from [48]).
© Copyright Policy
Related In: Results  -  Collection

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

life-05-00651-f013: (a) Phase diagram of DPPE/DOPC binary GUV. Fluorescence micrograph images in the figures show the appearance of a vesicle at the one phase and two phase region. MDPPE is the mole fraction of DPPE. (b) Adhesion diagram of DPPE/DOPC binary GUV. Circles, crosses and triangles indicate adhesion, non-adhesion and boundary states, respectively (taken from [48]).
Mentions: The hemifusion of GUVs induced by the inverse-cone-shaped lipid was realized using binary GUV composed of DPPE (inverse-cone-shaped lipid, Tm = 62 °C) and DOPC (cylinder-shaped lipid, Tm = −20 °C). The phase diagram is shown in Figure 13a, where the binary membrane with a DPPE mole fraction MDPPE >60% could not form GUVs due to the geometry of DPPE. Based on the phase diagram, the adhesion of the binary GUVs was examined by attaching two GUVs using a micro-manipulation technique. The obtained adhesion diagram for the DPPE/DOPC binary GUV is shown in Figure 13b, where circles indicate that the two GUVs adhere to one another in response to the contact, while cross symbols mean that the GUVs do not exhibit adhesion and triangles indicate the boundary region. The adhesion/non-adhesion boundary in Figure 13b agrees well with the immiscible boundary of the DPPE/DPPC binary vesicles in Figure 13a. In addition, when the temperature is increased so that one homogeneous phase region is present, the adhering vesicles separate spontaneously, indicating that the phase separation is responsible for the observed adhesion. A similar adhesion behavior was also confirmed for binary GUVs composed of DPhPC (inverse-cone-shaped lipid, Tm < −120 °C) and DPPC (cylinder-shaped lipid, Tm = 41 °C).

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