Model peptides and cholesterol

Proteins and lipids are the two major components of cell membranes. From the many membrane proteins and lipids, here we select one peptide (gramicidin) and two typical lipids (dimyristoyl- sn -glycero-3-phosphocholine (DMPC) and cholesterol) and develop a statistical mechanical model of this three-component membrane. This model is a combination of two of our previously developed membrane models: DMPC/cholesterol and DMPC/gramicidin. Using our model, the proportion of the densely packed area (i.e., the area covered by the rigid clusters) can be calculated if the compositions of the two layers of the membrane are the same. The results of our model can be experimentally tested by measuring the proportion of the densely packed area.