| Regional Biophysics Meeting 2005, March 16-20, Zreče, Slovenia | [MembBiophys] |
Interest in biophysical studies on the interaction of antimicrobial peptides and lipids has strongly increased because of the rapid emergence of antibiotic-resistant bacterial strains. Antimicrobial peptides exert their effects on cells largely by interacting with the lipids of their cell membranes and are able to distinguish between bacterial and eukaryotic membranes. Hydrophobicity of the peptides is one of the crucial determinants that affects function and specificity of peptides that interact with membranes. In the following work peptides have been investigated which are acylated analogs of a lactoferrin fragment. Attachment of a lipophilic chain into a peptide sequence allows the modulation of peptide hydrophobicity and affinity with membranes. These so called lipopetides have various lipophilic chains at the N-terminus which cause different bilayer destabilizing properties. This allows us to gain information about the role of chain length, position of the branched acyl group within the lipophilic chain and length of the side chain. The effects of lipopeptides have been tested on model membrane systems consisting of either dipalmitoyl-phoshatidylcholine (DPPC) as major component of mammalian cell membranes or dipalmitoyl-phoshatidylglycerol (DPPG) and dipalmitoyl-phoshatidylethanolamine (DPPE) as components of bacterial membranes. The effects on model membranes were determined by microcalorimetry, monolayer - techniques and X-ray diffraction. Supported by grant ANEPID (QLK2-CT-2002-01001) from the EC.
Email: guenter.deutsch@oeaw.ac.at
Address: Institute of Biophysics and X-ray Structure Research, Austrian Academy of Sciences, Schmiedlstraße 6, 8042 Graz, Austria