Limits...
Membrane fusion induced by small molecules and ions.

Mondal Roy S, Sarkar M - J Lipids (2011)

Bottom Line: Small molecules/ions do not share this advantage.Here we intend to present, how a variety of small molecules/ions act as independent fusogens.The detailed mechanism of some are well understood but for many it is still an unanswered question.

View Article: PubMed Central - PubMed

Affiliation: Chemical Sciences Division, Saha Institute of Nuclear Physics, Sector 1, Block AF, Bidhannagar, Kolkata 700064, India.

ABSTRACT
Membrane fusion is a key event in many biological processes. These processes are controlled by various fusogenic agents of which proteins and peptides from the principal group. The fusion process is characterized by three major steps, namely, inter membrane contact, lipid mixing forming the intermediate step, pore opening and finally mixing of inner contents of the cells/vesicles. These steps are governed by energy barriers, which need to be overcome to complete fusion. Structural reorganization of big molecules like proteins/peptides, supplies the required driving force to overcome the energy barrier of the different intermediate steps. Small molecules/ions do not share this advantage. Hence fusion induced by small molecules/ions is expected to be different from that induced by proteins/peptides. Although several reviews exist on membrane fusion, no recent review is devoted solely to small moleculs/ions induced membrane fusion. Here we intend to present, how a variety of small molecules/ions act as independent fusogens. The detailed mechanism of some are well understood but for many it is still an unanswered question. Clearer understanding of how a particular small molecule can control fusion will open up a vista to use these moleucles instead of proteins/peptides to induce fusion both in vivo and in vitro fusion processes.

No MeSH data available.


Related in: MedlinePlus

Binding of Ca2+ with PS headgroup.
© Copyright Policy - open-access
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3108104&req=5

fig3: Binding of Ca2+ with PS headgroup.

Mentions: Along with Ca2+, all other divalent cations are expected to follow a similar kind of mechanism of fusion. Although charge screening is necessary for the close association of the vesicles, but it is not sufficient to complete the fusion of PS containing vesicles. During fusion induced by Ca2+ or any other divalent cations, there is also an increase of membrane surface tension resulting in lateral compressibility and structural defects [16, 56]. This change in PS membrane surface is extremely necessary [49] for destabilization of the lipid bilayer along with surface charge screening by cations. Also, presence of Ca2+ or other divalent cations, the negative PS headgroups readily absorb the positive divalent ions, forming covalent bond through the carboxylate oxygen of the PS headgroup (Figure 3). This uptake of cations by the negatively charged sites of PS headgroups either cause the removal of structural water from the membrane surface [72], or cause the formation of “trans” “divalent cation-phosphatidylserine” complex. This brings the negatively charged PS headgroups close together; forcing the hydrocarbon phase of the membranes to face the hydrophobic phase [73, 74] thereby promoting the HII phase formation that is conducive for membrane fusion.


Membrane fusion induced by small molecules and ions.

Mondal Roy S, Sarkar M - J Lipids (2011)

Binding of Ca2+ with PS headgroup.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3108104&req=5

fig3: Binding of Ca2+ with PS headgroup.
Mentions: Along with Ca2+, all other divalent cations are expected to follow a similar kind of mechanism of fusion. Although charge screening is necessary for the close association of the vesicles, but it is not sufficient to complete the fusion of PS containing vesicles. During fusion induced by Ca2+ or any other divalent cations, there is also an increase of membrane surface tension resulting in lateral compressibility and structural defects [16, 56]. This change in PS membrane surface is extremely necessary [49] for destabilization of the lipid bilayer along with surface charge screening by cations. Also, presence of Ca2+ or other divalent cations, the negative PS headgroups readily absorb the positive divalent ions, forming covalent bond through the carboxylate oxygen of the PS headgroup (Figure 3). This uptake of cations by the negatively charged sites of PS headgroups either cause the removal of structural water from the membrane surface [72], or cause the formation of “trans” “divalent cation-phosphatidylserine” complex. This brings the negatively charged PS headgroups close together; forcing the hydrocarbon phase of the membranes to face the hydrophobic phase [73, 74] thereby promoting the HII phase formation that is conducive for membrane fusion.

Bottom Line: Small molecules/ions do not share this advantage.Here we intend to present, how a variety of small molecules/ions act as independent fusogens.The detailed mechanism of some are well understood but for many it is still an unanswered question.

View Article: PubMed Central - PubMed

Affiliation: Chemical Sciences Division, Saha Institute of Nuclear Physics, Sector 1, Block AF, Bidhannagar, Kolkata 700064, India.

ABSTRACT
Membrane fusion is a key event in many biological processes. These processes are controlled by various fusogenic agents of which proteins and peptides from the principal group. The fusion process is characterized by three major steps, namely, inter membrane contact, lipid mixing forming the intermediate step, pore opening and finally mixing of inner contents of the cells/vesicles. These steps are governed by energy barriers, which need to be overcome to complete fusion. Structural reorganization of big molecules like proteins/peptides, supplies the required driving force to overcome the energy barrier of the different intermediate steps. Small molecules/ions do not share this advantage. Hence fusion induced by small molecules/ions is expected to be different from that induced by proteins/peptides. Although several reviews exist on membrane fusion, no recent review is devoted solely to small moleculs/ions induced membrane fusion. Here we intend to present, how a variety of small molecules/ions act as independent fusogens. The detailed mechanism of some are well understood but for many it is still an unanswered question. Clearer understanding of how a particular small molecule can control fusion will open up a vista to use these moleucles instead of proteins/peptides to induce fusion both in vivo and in vitro fusion processes.

No MeSH data available.


Related in: MedlinePlus