Lipid Membrane Curvature Elasticity and Protein Function
It is suggested that curvature elastic stress of the monolayers of biomembrane lipid bilayers can change the activity of certain imbedded membrane proteins and that this may be a rationale for the lipid compositions seen in cell membranes. Lipid monolayer curvature stress arises when lipids which are prone to exhibit nonlamellar mesomorphic phases are a large fraction of the lipids of bilayers. The stress builds as one approaches the boundry of a lamellar-nonlamellar phase transition form the lamellar side. A discussion is given of the competition governing the release of curvature stress during the formation of interfacially curved mesomorphs. The net stress energy in bilayers near to a transition is in the range of a few to perhaps ten times thermal (kT) energy per lipid molecule. Mechanisms of coupling this stress to protein conformational changes are given.
KeywordsLipid Bilayer Lipid Molecule Line Tension Lipid Monolayer Spontaneous Curvature
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- Cullis, P. R., Hope, M. J., de Kruijff, B., Verkleij, A. J. and Tilcock, C. P. S., 1985, Structural properties and functional roles of phospholipids in biological membranes, in: Phospholipids and Cellular Regulations, Vol. 1, J. F. Kuo, eds., CRC Press, Boca Raton, FL.Google Scholar
- Evans, E. A. and Skalak, R., 1979, Mechanics and thermodynamics of biomembranes, CRC Critical Rev. in Bioeng. 3: 180–419.Google Scholar
- Gruner, S. M., 1991, Nonlamellar lipid phases, in: The Structure and Function of Cell Membranes, P. L. Yeagle, ed., Telford Press, Caldwell, NJ (in press).Google Scholar
- Helfrich, W., 1973, Elastic properties of lipid bilayers: Theory and possible experiments, Z. für Naturforschung 28c: 693–703.Google Scholar
- Helfrich, W., 1980, Amphiphilic mesophases made of defects, in Physics of Defects, R. Balian, M. Kleman and J-P. Poirier, eds., North-Holland, Amsterdam.Google Scholar
- Luzzati, V., 1968, X-ray diffraction studies of lipid-water systems, in Biological Membranes, Vol. 1, D. Chapman, ed., Academic Press, NY.Google Scholar
- Tate, M. W., Eikenberry, E. F., Turner, D. C., Shyamsunder, E. and Gruner, S. M., 1991, Nonbilayer phases of membrane lipids, Chem. Phys. Lipids (in press).Google Scholar