Premium
Solvent effects on the cooperative order–disorder transition of aqueous solutions of schizophyllan, a triple‐helical polysaccharide
Author(s) -
Hirao Takayuki,
Sato Takahiro,
Teramoto Akio,
Matsuo Takasuke,
Suga Hiroshi
Publication year - 1990
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.360291417
Subject(s) - chemistry , aqueous solution , solvent , molecule , polysaccharide , triple helix , side chain , solvent effects , polymer chemistry , crystallography , computational chemistry , organic chemistry , stereochemistry , polymer
A triple‐helical polysaccharide schizophyllan in aqueous solution exhibited a highly cooperative transition between ordered and disordered states associated with the conformation of its side chains and nearby water molecules. The transition was followed by optical rotation and containing additives such as NaOH and DMSO as solvents. The ordered state was stabilized or destabilized or depending on the kind and amount of the additive employed; in particular, the addition of DMSO had a remarkable stabilizing effect. This effect was analyzed by means of a statistical mechanical theory of linear cooperative transitions, where DMSO was assumed to interact favorably with the ordered side chains. A small amount of NaOH in a solvent mixture stabilized the ordered state and made the transition curve very gradual. No molecular mechanism was elucidated to account for the role of NaOH.