The continuing emergence of antibiotic resistant bacterial strains has highlighted the importance of identifying and developing new therapeutic agents. In 26 July Nature Sara Fernadez-Lopez and colleagues from the Skaggs Institute for Chemical Biology, California describe six- and eight-residue cyclic D,L-α-peptides that preferentially act upon the membranes of both Gram positive and Gram negative bacteria.
Fernadez-Lopez et al. observed that amphiphilic D,L-α-peptides having three consecutive hydrophilic residues and repeating L-tryptophan and D-leucine residues can self-assemble into tubular structures that span synthetic membranes. These structures allow the highly efficient transport of ions and other small species across lipid bilayers (Nature 2001, 412:452-455).
By using single negatively charged amino acid substitutions they were able to modify the activity of individual peptides and used these against a variety of pathogenic bacteria. In vitro testing with multiple resistant Staphylococcus aureus (MRSA) and Escherichia coli showed up to 20-fold increased anti-bacterial activity. In addition the ...
