0000000000247752
AUTHOR
Simon Faiß
Melting and interdigitation of microstructured solid supported membranes quantified by imaging ellipsometry
The phase transition of individually addressable microstructured lipid bilayers was investigated by means of noncontact imaging ellipsometry. Two-dimensional membrane compartments were created on silicon substrates by micromolding in capillaries and the phase transition of supported dimyristoylphosphadiylcholine DMPC and dipentadecoylphosphatidylcholine DiC15PC membranes was determined measuring area expansion and thickness of the bilayer as a function of temperature, ethanol concentration, and cholesterol content. Apart from measuring the thermotropic behavior of DMPC on glass slides and silicon wafers, the authors were able to visualize the reversible induction of an interdigitated phase …
Partially Reversible Adsorption of Annexin A1 on POPC/POPS Bilayers Investigated by QCM Measurements, SFM, and DMC Simulations
The kinetics of annexin A1 binding to solid-supported lipid bilayers consisting of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC)/1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoserine (POPS; 4:1) has been investigated as a function of the calcium ion concentration in the bulk phase. Quartz crystal microbalance measurements in conjunction with scanning force microscopy, fluorescence microscopy, and computer simulations indicate that at a given Ca2+ concentration annexin A1 adsorbs irreversibly on membrane domains enriched in POPS. By contrast, annexin A1 adsorbs reversibly on the POPC-enriched phase, which is composed of single POPS molecules embedded within a POPC matrix. The overall are…