Two groups of amphipathic peptides, based on the Schiffer/Edmundson helical-wheel
model, were designed, synthesized and their antimicrobial and hemolytic activities were studied. The
first group includes the peptides X-RWLRLLWRFLRL- NH2, where X=H, Ac, Ahx (aminohexanoic)
and Myr (Myristoyl). Specific substitutions were introduced in the hydrophobic /hydrophilic face or
the N-terminal group in order to investigate how these modifications affect their antimicrobial activity.
The second group comprises three analogs of aurein 1.2 H- GLFDIIKKIAESF-NH2, a natural antimicrobial
amphipathic peptide, obtained by replacing Gly with Ala, Val and Leu successively. The influence
of these modifications on the reactivity of aurein was also studied. The helical conformation of
the synthetic peptides was evaluated by circular dichroism. Comments regarding the nature, the total charge and the availability
of the N-terminal groups are discussed in relation to the antimicrobial reactivity of the reported peptides.