Publication Details (including relevant citation information):
Y. Takechi, Y. Shintani, D. Kimoto, E. Okamura, Membrane,40, 38-45 (2015).
The regulation of the phospholipid protrusion, the vertical fluctuation at the surface of cell-sized vesicles (CSVs), was investigated by solution NMR in combination with the 1H-1H nuclear Overhauser effect (NOE) enhancement measurement. Using deuterated bisphenol A (BP-d) and palmitic acid (PA-d) as model hydrophobic components, we compared how the lipid protrusion is modulated by the presence of BP-d and PA-d in the fluid, soft CSV membrane. It is found that the phospholipid protrusion is suppressed by BP-d but not by PA-d, although both BP-d and PA-d are trapped in the membrane inside. The contrasting effect of BP-d and PA-d on the protrusion motion is interpreted by the difference in the mode of interaction between these substances and lipids in the membrane; rather hydrogen bonding than van der Waals forces is the decisive parameter to regulate the phospholipid protrusion motion.