Random close-packed arrays of membrane components

Abstract

Consideration is given to random close-packed arrangements of membrane components in two-dimensional bilayer structures. Such arrangements are simulated by studying two-dimensional close-packed random arrangements of different sized discs (or plates). One disc is used to simulate a lipid hydrocarbon chain whilst the other disc (or plate) simulates either a cholesterol molecule or the stem of an intrinsic protein. It is assumed that the sole interaction between the components is the steric repulsion which prevents the molecules from overlapping. The arrays provide a useful visual representation which enables the consequences of such random arrangements of membrane components to be examined and enables the contacts which can occur between the two components to be counted. The approach, whilst crude, appears to provide some insight into arrangements of membrane components and points to questions which require further consideration.