%0 Generic %A Abuillan, Wasim %D 2013 %F heidok:15735 %R 10.11588/heidok.00015735 %T Fine-Structures, Lateral Correlation and Diffusion of Membrane-Associated Proteins on Biological Membrane Surfaces %U https://archiv.ub.uni-heidelberg.de/volltextserver/15735/ %X The primary aim of this thesis is to investigate the lateral diffusion, correlation and interactions of proteins and peptides with cell membrane models by the combination of experimental techniques in real and reciprocal space. In Chapter 4, the characteristic distance and range of lateral correlation between non-crystalline proteins anchored to fluid lipid monolayers at high surface densities were determined by grazing incidence small angle X-ray scattering (GISAXS) for the first time. Moreover, the lateral density of membrane-anchored proteins could be quantified from Sulfur Kα emission detected by grazing incidence X-ray fluorescence (GIXF). In Chapter 5, the influence of molecular crowding on the lateral diffusion of membrane-anchored proteins was investigated by fluorescence recovery after photobleaching and single particle tracking microscopy, yielding a clear transition from free diffusion to confined diffusion. In Chapter 6, the interactions between antimicrobial peptides and bacterial membrane models are probed by GIXF that allows for the identification of the spatial localization of ions with Ångstrom accuracy. This enabled one to discriminate different "modes" of membrane-protein interactions, such as adsorption and incorporation on the molecular level. The obtained results demonstrated that the use of real and reciprocal space techniques can provide information about fine-structures, electrostatics, and dynamic correlation at biological interfaces.