Synthesis of α-Helices Having a Positively Charged Random Coil-Block on Either N- or C-Terminal

To study a charge-induced stabilization of α-helix, α-helical peptides having a positively charged random-coil block on either N- or C-terminal of the helix, and having a strictly defined length, (Ala)20(X)20Phe and (X)20(Ala)20Phe (X=Lys or Orn), were synthesized. Component dipeptides were coupled on p-(oxymethyl)phenylacetamidomethyl polystyrene.