Related Experiment Videos
The hemifusion intermediate and its conversion to complete fusion: regulation by membrane composition
L Chernomordik1, A Chanturiya, J Green
1Laboratory of Theoretical and Physical Biology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA.
Biophysical Journal
|September 1, 1995
Summary
Membrane fusion involves lipid bending. Adding lysophosphatidylcholine to contacting monolayers inhibited hemifusion, while its effect on fusion pores depended on the distal monolayer, suggesting distinct intermediates in membrane fusion.
Area of Science:
- Membrane biophysics
- Lipid bilayer dynamics
- Cellular fusion mechanisms
Background:
- Membrane fusion requires lipids to bend, with spontaneous curvature influencing energy minimization.
- Lysophosphatidylcholine and arachidonic acid induce opposing spontaneous curvatures in lipid monolayers.
Purpose of the Study:
- To investigate the role of spontaneous curvature in membrane fusion intermediates.
- To determine how different lipid monolayers influence hemifusion and fusion pore formation.
Main Methods:
- Utilized planar phospholipid membranes and lipid vesicles.
- Introduced lysophosphatidylcholine and arachidonic acid to specific membrane monolayers.
- Observed and analyzed hemifusion and fusion pore formation.
Main Results:
- Lysophosphatidylcholine on contacting monolayers inhibited hemifusion between vesicles and planar membranes.
- Fusion pore formation was promoted by lysophosphatidylcholine and inhibited by arachidonic acid on the distal monolayer.
- Hemifusion and fusion pore intermediates involve different monolayers and potentially opposite net curvatures.
Conclusions:
- Hemifusion and fusion pore formation exhibit distinct monolayer dependencies and curvature preferences.
- Biological fusion processes may utilize intermediates with opposing net curvatures, mediated by specific lipid compositions.