Article pubs.acs.org/Langmuir
Conformational, Dynamical. and Tensional Study of Tethered Bilayer Lipid Membranes in Coarse-Grained Molecular Simulations Chueh Liu and Roland Faller* Department of Chemical Engineering and Materials Science, University of California-Davis, Davis, California 95616, United States S Supporting Information *
ABSTRACT: Tethered bilayer lipid membranes (tBLMs) have attracted great interest recently due to their crucial roles in elucidating fundamental membrane characteristics and the implications in biochemical sensors and pharmaceutical drug carriers. Nevertheless, they have not yet been investigated computationally on the molecular scale. Here, we study tBLMs consisting of DOPCs (1,2-dioleoyl-sn-glycero-3phosphocholine) as free lipids and pegylated DOPCs (on phosphate group) as tethers in water by a variation of the MARTINI model. By varying grafting densities and tether lengths, distinct conformational changes from planar to undulated bilayers are observed. Lateral diffusivities and lateral pressure profiles show that the dynamical and tensional states are specific to the system configurations. These results suggest that the conformations, fluidity, and elasticity of the tBLMs can be tuned and manipulated to conform to various requirements in theoretical investigations and technological applications.
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INTRODUCTION Biomembranes composed of lipid bilayers are crucial in biological systems for separating the cytoplasm from the environment and regulating membrane protein functions. They have also applications in drug delivery systems1−6 for cancer treatment and biosensors7,8 for homeland security. Nevertheless, the complexity of real biomembranes hinders understanding of cellular mechanisms and development in technological applications. Simplified model membranes, such as supported lipid bilayers,9,10 are therefore investigated for the structural and functional properties. However, the study of membrane proteins is limited by the shallow water layer11 (
