THE COMPUTER AS A LABORATORY FOR THE PHYSICAL-CHEMISTRY OF MEMBRANES

A mini-review is given of some recent advances in the use of computer- simulation approaches to the study of physico-chemical properties of l ipid bilayers and biological membranes. The simulations are based on m icroscopic molecular interaction models as well as random-surface mode ls of fluid membranes. Particular emphasis is put on those properties that are controlled by the many-particle character of the lamellar mem brane, i.e. correlations and fluctuations in density, composition and large-scale conformational structure. It is discussed how dynamic memb rane heterogeneity arises and how it is affected by various molecular species interacting with membranes, such as cholesterol, drugs, insect icides, as well as polypeptides and integral membrane proteins. The in fluence of bending rigidity and osmotic-pressure gradients on large-sc ale membrane conformation and topology is described.