Infrared spectroscopy of supported lipid monolayer, bilayer, and multibilayer membranes

Cecropin A was examined in supported monolayer, bilayer, and multibilayer l ipid membranes using attenuated total internal reflection Fourier-transform infrared spectroscopy. The spectral features provide an abundance of infor mation about the conformation and orientation of the peptide, as well as ab out the effects of the peptide on lipid order. In this case, they serve to contrast results from the three preparations. The results of monolayer and bilayer studies are generally similar, although differences in the nature o f the membranes appear to cause minor changes in the conformation and orien tation of the peptide. The results of the multibilayer studies are differen t in many respects from those of the monolayer and bilayer studies, suggest ing that fundamentally different peptide-lipid interactions occur in multib ilayers. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.