Conformation of branched polypeptides based on poly(L-lysine): Circular dichroism study

Abstract

Circular dichroism (CD) spectra of branched (multichain) polypeptides based on poly(L-lysine) with DL-alanine and other amino-acid residues in the side chain have been measured under various conditions of pH. The spectra were interpreted using spectra of poly(L-lysine) as standard. No straightforward correlation between polypeptide CD spectra and their structure could be detected. The contribution of the side chain CD to that of the main chain is additive in some cases, but in other cases qualitatively different CD spectra arise. The reason for this CD behavior is discussed.