Protein-lipid\membrane interactions are fundamentally important to biological processes. We have examined the role protein hydrophobicity in protein-membrane interactions (rb1210133), finding that membrane disruption positively correlates with the hydrophobicity of amphiphillic proteins. For this study we examined the interaction purothionins ( antimicrobial proteins from higher plants) with silicon surface deposited asymmetrical bilayers mimicking the outer membrane of gram negative bacteria. We propose to continue this study by assessing how the fluidity of the membrane affects the ability of an amphiphillic protein to partition into the interior of the membrane. To do this we propose to examine the interaction of alpha1-purothionin with an asymmetric DPPC/rc-Lipopolysaccharide bilayer from 5-35 degrees Celsius. This study will advance our understanding of protein-membrane interactions