Molecular Theory of Chain Packing, Elasticity and Lipid-Protein Interaction in Lipid Bilayers

This chapter describes relationships, starting out from a microscopic, molecular picture of amphiphile organization in the membrane. Fluid bilayers are very flexible because they can relax a shear stress by hydrodynamic flow. The most important elastic modulus is their bending rigidity which may be related to the molecular structure of the membrane as reviewed in the chapter. Biological membranes, the subject matter of this volume, are extremely complex physico–chemical systems, not to mention their biological aspects. Even the “model” amphiphilic bilayers, which have been considered and which serve to mimic real membranes are also very complex many-body systems. In addition to their biological relevance, these systems are interesting and challenging theoretically because of the special coupling between their microscopic and macroscopic behaviors and because of their self-organizing characteristics. Most of the relevant information on either biological or model membranes is, naturally, experimental. On the other hand, analytical theories, such as mean field models, often provide the explicit parameter dependence. Furthermore, mean field theories may also be useful in suggesting the parameters and conditions that should be studied via simulation.