The effect of peptides derived from protein transmembrane domains on membranes

Rich structure of cell membranes raises broad number of questions regarding the mechanisms driving and regulating processes taking place on membranes. The thesis presents four articles investigating organization of lipid membranes and peptide-lipid interactions. The experiments were performed on model lipid membranes. These simplified systems that partially mimic cell membranes enable to study protein-lipid interactions at the molecular level and membrane physico-chemical properties in a controlled way. Advanced fluorescence techniques such as FCS, TDFS, FLIM and anisotropy were used for the system characterization. First publication describes newly designed fluorescence dyes based on boron dipyrromethene structure, the so- called molecular rotors, which are reported to be viscosity-sensitive probes. Detailed analysis of fluorescence lifetime of excited state of the molecular rotors inserted into lipid membranes showed diverse incorporation of dyes into membranes and their reorientation in membranes of different rigidity. The second part investigates existence of lipid nanodomains in membranes caused by the presence of a cross-linker. Even though standard fluorescence microscopy techniques do not allow direct visualization of the nanodomains, we were able to detect these structures by employment of..