Coiled-coil formation on lipid bilayers--implications for docking and fusion efficiency
Gesa Pähler1, Cornelia Panse, Ulf Diederichsen
1Institute of Physical Chemistry, Georg August University, Göttingen, Germany.
Biophysical Journal
|January 4, 2013
Summary
This study investigates coiled-coil formation in peptides, revealing parallel orientations are crucial for membrane fusion, while antiparallel structures only facilitate docking. Binding constants are higher in solution than at interfaces.
Area of Science:
- Biochemistry
- Biophysics
- Materials Science
Background:
- Eukaryotic SNARE motifs mediate membrane fusion through coiled-coil interactions.
- Minimal peptide mimics are valuable tools for studying these complex biological processes.
Purpose of the Study:
- To characterize coiled-coil formation of synthetic peptides in solution and at membrane interfaces.
- To investigate the role of peptide orientation (parallel vs. antiparallel) in complex formation and membrane fusion.
Main Methods:
- Circular dichroism spectroscopy, surface plasmon resonance, and attenuated total reflection infrared spectroscopy were used.
- Peptides rich in glutamic acid or lysine were synthesized, including reverse sequences.
- Peptides were covalently attached to phospholipid anchors to form membrane interfaces.
Main Results:
- Coiled-coil formation was confirmed on hydrogels and membranes.
- Parallel coiled-coil structures were essential for hemifusion and full membrane fusion.
- Antiparallel coiled-coil motifs mediated only docking, not fusion.
- Binding constants were higher in solution compared to membrane interfaces due to entropic effects.
Conclusions:
- Peptide orientation dictates the outcome of membrane interactions, from docking to fusion.
- Understanding coiled-coil behavior at interfaces is key for designing biomimetic fusion systems.
- The study provides insights into the fundamental mechanisms of SNARE-mediated membrane fusion.
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