Molecular Dynamics of Phosphatidylcholine Model Membranes of Splenic Lymphoma Cells

In eukaryotic cell membranes, phosphatidylcholine (PC) is one of the most prevalent phospholipids. Using the CHARMM36 lipid force field, we conducted molecular dynamics (MD) simulations on phosphatidylcholine (PC) only headgroup with varied fatty acid chains. Specifically, we investigated five PC components: 1,2-diauroyl-sn-glycero-3-phospocholine (DLPC), 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), 1,2-dipalmitoyl-sn-glycero-3- phospcholine (DPPC), 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), and 1- stearoyl-2-oleoylphosphatidylcholine (SOPC) in both pure and cancer model of PCs. We analyzed various characteristics such as lipid area, lateral compressibility, deuterium order parameter, bilayer thickness, radial distribution functions, and electron density. Our research revealed that PCs in the cancer model membrane are larger in surface area per lipid compared with pure PC membranes. This suggests that our PC model for cancer PCs may be more permeable and porous compared to pure PC membraness. In general, chain order parameter values were lower in cancer PCs compared to pure PCs. The electron density studies of cancer PCs revealed a decrease in bilayer thickness as temperature increases, indicating that cancer PCs experience thinning at higher temperatures. Overall, our results give insight into significant differences between the cellular makeup and functioning of pure PCs and cancer PCs at the molecular level.