Computational simulation of lipid bilayer reorientation at gaps

Understanding cellular membrane processes is critical for the study of events such as viral entry, neurotransmitter exocytosis, and immune activation. Supported lipid bilayers serve as a model system for many membrane processes. Despite the relative simplicity of this system, many important structural and dynamic parameters are not experimentally observable with current techniques. Computational approaches allow the development of a high-resolution model of bilayer processes. We have performed molecular dynamics simulations of phospholipid bilayers to model the creation of bilayer gaps and to analyze their structure and dynamics. Our simulations show rapid reorientation and movement of phospholipids near simulated bilayer edges. These data suggest that lipids may undergo rapid local rearrangements during membrane fusion, facilitating formation of fusion intermediates thought key to the infection cycle of viruses such as influenza and HIV.