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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

Sulfatide.
© Copyright Policy - open-access
Related In: Results  -  Collection


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fig4: Sulfatide.

Mentions: Other than PS vesicles, where electrostatic or charge-charge interaction plays a critical role during fusion, Ca2+ is also able to induce membrane fusion in vesicles containing lipids like PE and so forth. It has been found that 10 mM of Ca2+ enhances fusion of SUVs of dioleoylphosphatidylethanolamine (DOPE) containing less than 30 mole % sulfatides (Figure 4) [75]. The progress of fusion is monitored using two well-known assays, namely, NBD-PE/N-Rh-PE assay for lipid mixing and Tb/DPA assay for content mixing. PE has a natural tendency to fuse, but it is the negative charge of the sulphate (SO42−) moiety of sulfatides that prevents the inverted hexagonal (HII) phase formation in the DOPE vesicles by interfacial hydration, and hence this leads to the stabilization of the DOPE-sulfatide SUVs [76, 77]. The binding of positively charged Ca2+ to the negatively charged sulfatides not only neutralizes the negative charge present on the membrane surface, but also reduces bound water, thereby dehydrating the membrane surface [78]. This results in the formation of nonlamellar intermediate as the PE molecules revert back to the HII phase [79, 80]. Thus, fusion occurs following similar “destabilization of the membrane surface” mechanism as mentioned in case of pure Ca 2+-induced fusion.


Membrane fusion induced by small molecules and ions.

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

Sulfatide.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig4: Sulfatide.
Mentions: Other than PS vesicles, where electrostatic or charge-charge interaction plays a critical role during fusion, Ca2+ is also able to induce membrane fusion in vesicles containing lipids like PE and so forth. It has been found that 10 mM of Ca2+ enhances fusion of SUVs of dioleoylphosphatidylethanolamine (DOPE) containing less than 30 mole % sulfatides (Figure 4) [75]. The progress of fusion is monitored using two well-known assays, namely, NBD-PE/N-Rh-PE assay for lipid mixing and Tb/DPA assay for content mixing. PE has a natural tendency to fuse, but it is the negative charge of the sulphate (SO42−) moiety of sulfatides that prevents the inverted hexagonal (HII) phase formation in the DOPE vesicles by interfacial hydration, and hence this leads to the stabilization of the DOPE-sulfatide SUVs [76, 77]. The binding of positively charged Ca2+ to the negatively charged sulfatides not only neutralizes the negative charge present on the membrane surface, but also reduces bound water, thereby dehydrating the membrane surface [78]. This results in the formation of nonlamellar intermediate as the PE molecules revert back to the HII phase [79, 80]. Thus, fusion occurs following similar “destabilization of the membrane surface” mechanism as mentioned in case of pure Ca 2+-induced 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