Protein-membranes interactions are fundamentally important to biological function. We have developed advanced models of the Gram negative bacterial outer membrane and have examined the interaction of a1-Purothionin (Pth) with these models under different conditions to structurally probe the mode in which cationic amphiphilic proteins such as thionins and defensins interact with bacterial membranes to exert their antimicrobial activity. Results to date reveal that the interaction of a1-Pth with the bilayer tails appears to be mediated by bilayer defects. However, the lack of a mobile inner bilayer leaflet in the silicon supported bilayers studied maybe hampering the proteins interaction. Therefore here, we plan to examine the interaction of a1-Pth with free floating asymmetric models of the Gram negative bacterial outer membrane to gain further structural insights into h