Solvent relaxation in phospholipids bilayers: physical understanding and biophysical applications.

Abstract:
After the uderstanding of solvent relaxation (SR) in isotropic solvents, scinetists started abour 10 years ago to characterise SR in biosasemblies. It was our group that established the SR method for probing micro-mobilities and -polarities in biomembranes. Despite several applications of the SR method in membrane research, the origin of the observed slow SR kinetics probed by dyes defined localised in the external interface, headgroup region, or backbone region of the bilayer is still unclear. We suggest to combine defined fluorescence experiments with molecular dynamic simulations in order to elucidate the origin of the nanosecond SR kinetics observed in the headgroup and backbone region of lipid bilayers. The second part of the proposal comprises an application of the SR approach in an actual question in protein sciences, the characterisation of the interaction of the alfa-defensine cryptidin-4 with membranes in order to understand the bactericidal properties of this protein.