Does oxidative damage enhance or hinder antimicrobial peptide insertion into model bacterial lipid monolayers?

A number of antimicrobial agents work, at least in part, by interacting with the lipid layers of microbial cells, the composition of which differs in significant ways from that of mammalian cells. For instance, the antibacterial peptide protegrin is known to interact preferentially with bacterial membranes, which contain large amounts of anionic lipids, such as phosphoglycerol, PG, lipids, rather than mammalian cell membranes which are richer in phosphocholine, PC, lipids. The lipids layers of both microbial and mammalian cells are subject to continuous oxidative attack. In this proposal we wish to explore how the presence of oxidized lipids within model bacterial lipid monolayers changes the extend and nature of the interaction with protegrin. The results will lead to a better understanding of how antimicrobial peptides interact with more realistic models of bacterial membranes.