[Analysis Example] Coarse-grained models for lipid membranes 

Lipid molecules are the major components of biomembranes, and various lipid molecules self-aggregate to form planar or spherical membranes. When lipid membranes are analyzed by molecular simulation, full-atomistic models or coarse-grained models are used.[1] Here we present some example models using the MARTINI coarse-grained model.[2]
Figure 1 shows a planar bilayer membrane composed of DPPC, a type of phospholipid, and cholesterol. The analysis of lipid membranes is focused on the structural characteristics such as thickness, density and mechanical properties.[3]

Lipid Nano Particles (LNPs) composed of lipids are used for drug delivery due to their high biocompatibility. Figure 2 shows a model of LNP of about 2 nm in diameter composed of DPPC, DOPC, and cholesterol, which can be easily modeled by J-OCTA and analyzed by MD calculations.

Figure 1. A Coarse-grained (MARTINI) model of lipid membranes composed of DPPC and CHOL.

Figure2. An LNP model composed of DPPC/DOPC/CHOL.