The precipitation of poly‐<scp>L</scp>‐glutamic acid. II. β‐Precipitation

Abstract

Abstract Infrared and X‐ray diffraction studies have established that in the β‐precipitation region of poly‐ L ‐glutamic acid the chains are in the β‐conformation. Therefore, a major molecular conformational change has taken place upon precipitation. It is shown that the size of the α‐helical aggregates remains constant with time in the β‐region. Strong evidence can be offered to indicate that the transformation involves a transitory random‐coil intermediate. Reasons are advanced, in view of the stability of the β‐form, as to why two distinct precipitation regions exist.