Grazing incidence X-ray diffraction of highly aligned phospholipid membranes containing the antimicrobial peptide magainin 2

We present the first study of grazing incidence X-ray diffraction on a mode l system of phospholipid membranes and antimicrobial peptides. For this pur pose, highly oriented multilamellar samples have been prepared on solid sub strates. By this technique, the short-range order of the lipid chains in th e fluid L-alpha phase can be investigated quantitatively, including not onl y the mean distance between acyl chains, but also the associated correlatio n length. The short-range order in lecithin is found to be severely affecte d by the amphiphilic peptide magainin 2.