Conformational studies of sequential polypeptides containing lysine and tyrosine

Abstract

Abstract The conformation of three sequential copolypeptides, poly( L ‐tyrosyl‐ L ‐lysine), poly( L ‐tyrosyl‐ L ‐lysyl‐ L ‐lysine), and poly[ L ‐tyrosyl‐( L ‐lysyl) 2 ‐ L ‐lysine] have been studied by a variety of techniques, including CD, ir spectroscopy, analytical ultracentrifugation, and x‐ray diffraction. Depending upon the pH and sovent composition, poly( L ‐tyrosyl‐ L lysyl‐ L ‐lysine) and poly [ L ‐tyrosyl‐( L lysyl) 2 ‐ L ‐lysine] can adopt either the α‐helical or random‐coil conformation, while poly( L ‐tyrosyl‐ L ‐lysine) forms either inter‐ or intramolecular β‐structures.