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

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


getmorefigures.php?uid=PMC3108104&req=5

fig7: Ethanol.

Mentions: Short-chain alcohols are found to induce the hemifusion process which finally leads the process to fusion. It is already known that general fusogens induce the formation of the HII phase, which in turn stabilizes the hemifusion intermediate to promote fusion. Short-chain alcohols are expected to work differently. Alcohols, mostly methanol and ethanol (Figure 7), do not alter the curvature of the membrane bilayer. Both methanol and ethanol apparently support positive spontaneous curvature of lipid monolayers [97, 98]. That is why it is highly unlikely for them to induce the formation of the HII phase. Researchers have found that short-chain alcohols like ethanol can induce the formation of the hemifusion or stalk intermediate in GUVs [99]. Moreover, ethanol is reported to induce the fusion of PC SUVs [100]. Imaging techniques like fluorescence microscopy and freeze fracture electron microscopy were used to monitor the fusion processes. Both the authors pointed that it was not the HII phase formation but the destabilization of the outer membrane monolayer that led the process to complete fusion. During the formation of hemifusion or stalk intermediate, it was proposed that short-chain alcohols disrupted the outer leaflet of lipid layer to cause the local breakage of the monolayer to induce the stalk formation [99]. During stalk formation, the hydrophobic voids are created between the bilayer leaflets [101]. It was proposed that ethanol affected the lipid chain packing in the void region to decrease the energy of the hydrophobic voids to stabilize the stalk intermediate [102].


Membrane fusion induced by small molecules and ions.

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

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

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

fig7: Ethanol.
Mentions: Short-chain alcohols are found to induce the hemifusion process which finally leads the process to fusion. It is already known that general fusogens induce the formation of the HII phase, which in turn stabilizes the hemifusion intermediate to promote fusion. Short-chain alcohols are expected to work differently. Alcohols, mostly methanol and ethanol (Figure 7), do not alter the curvature of the membrane bilayer. Both methanol and ethanol apparently support positive spontaneous curvature of lipid monolayers [97, 98]. That is why it is highly unlikely for them to induce the formation of the HII phase. Researchers have found that short-chain alcohols like ethanol can induce the formation of the hemifusion or stalk intermediate in GUVs [99]. Moreover, ethanol is reported to induce the fusion of PC SUVs [100]. Imaging techniques like fluorescence microscopy and freeze fracture electron microscopy were used to monitor the fusion processes. Both the authors pointed that it was not the HII phase formation but the destabilization of the outer membrane monolayer that led the process to complete fusion. During the formation of hemifusion or stalk intermediate, it was proposed that short-chain alcohols disrupted the outer leaflet of lipid layer to cause the local breakage of the monolayer to induce the stalk formation [99]. During stalk formation, the hydrophobic voids are created between the bilayer leaflets [101]. It was proposed that ethanol affected the lipid chain packing in the void region to decrease the energy of the hydrophobic voids to stabilize the stalk intermediate [102].

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