Interaction of water with poly-α-amino acids. I. Relationships between conformation and relaxation processes

✍ Scribed by H. Shiraishi; A. Hiltner; E. Baer

• Book ID: 102764732
• Publisher: Wiley (John Wiley & Sons)
• Year: 1976
• Tongue: English
• Weight: 522 KB
• Volume: 15
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/bip.1976.360150611

✦ Synopsis

Abstract

The relaxation behaviour of the sodium salt of poly (L‐glutamic acid) in the solid state has been examined by means of dynamic mechanical spectroscopy. Bound water was found to exert a profound influence on the relaxation behaviour and on a bulk property, the rigidity. Certain features of the loss spectrum have been identified with the hydration‐dependent β‐to‐α conformational transition. Thus two side‐chain relaxations are observed below ambient temperature, one associated with the β from (β~1~^β^) and a second at a lower temperature associated with the α form (β~1~^α^). The greater rigidity of the α form below the relaxation temperature and the larger rigidity drop accompanying the β~1~^α^ can be explained in terms of the structural differences of the two conformations.