Conformational studies on polypeptides. The effect of sodium perchlorate on the conformation of poly-L-lysine and of random copolymers of L-lysine and L-phenylalanine in aqueous solution.

Abstract

AbstractCircular Dichroism measurements have been carried out on poly‐L‐lysine (PLL) and on random copolymers of lysine and phenylalanine at various pH values and in the presence of different amounts of NaClO4. The results indicate that either the homopolymer or the copolymers at pH conditions at which the side‐chain amino groups are fully protonated, assume the right‐handed α‐helical conformation in the presence of NaClO4. The results are interpreted in terms of specific binding of ClO4− ions on charged side‐chain amino groups.