Exploring the antibacterial and hemolytic activity of shorter- and longer-chain β- α,β-, and γ-peptides, and of β-peptides from β2-3-aza- and β3-2-methylidene-amino acids bearing proteinogenic side chains -: A survey

The antibacterial activities of 31 different beta-, mixed alpha/beta-, and gamma-peptides, as well as of beta-peptides derived from beta(2)-3-aza- and beta(3)-2-methylidene-amino acids were assayed against six pathogens (Enterococcus faecalis, Staphylococcus aureus, Streptococcus pneumoniae, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa), and the results were compared with literature data. The interaction of these peptides with mammalian cells, as modeled by measuring the hemolysis of human erythrocytes, was also investigated. In addition to those peptides designed to fold into amphiphilic helical conformations with positive charges on one face of the helix, one new peptide with hemolytic activity was detected within the sample set. Moreover, it was demonstrated that neither cationic peptides used for membrane translocation (beta(3)-oligoarginines), nor mixed alpha/beta- or gamma-peptides with somatostatin-mimicking activities display unwanted hemolytic activity.