ABSTRACT

The development of particle-based mesoscopic models arose from the necessity to bridge the gap between the macroscopic description of biomembranes, viewed as thin elastic sheets, and the atomistic description. Within the particle-based description, groups of atoms or molecules are modeled by a set of particles, or beads. This leads to a considerable decrease in the computational time needed to solve the equations of motion of the system. Mesoscopic particle-based modeling of lipid membranes therefore enables to investigate phenomena that occur well beyond the time and length scales accessible by all-atoms simulations. Since the 1990s, the particle-based mesoscopic approach has been used to study specific biomembrane systems as well as generic ones, and to investigate biomembrane phenomena occurring both at small length scales and large ones. Because particle-based models retain some of the molecular or sub-molecular details of the systems, e.g., small length-scale deformations, such models can also be used to study the influence of small length-scale perturbations on the behavior of the whole large-scale system. The aim of this chapter is to introduce the mesoscopic particle-based approach and show how, depending on the model and simulation method, it enables to study very different biomembranes systems and phenomena. In this chapter, the results from some selected simulation studies that illustrate how the mesoscopic particle-based approach can contribute to the understanding of lipid membrane phenomena are presented. These range from understanding of what triggers phase changes in free standing and supported lipid bilayers, to what induces morphological changes in lipid membranes.