Premium
Structural components of alginic acid. II. The crystalline structure of poly‐α‐ L ‐guluronic acid. Results of X‐ray diffraction and polarized infrared studies
Author(s) -
Atkins E. D. T.,
Nieduszynski I. A.,
Mackie W.,
Parker K. D.,
Smolko E. E.
Publication year - 1973
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.1973.360120814
Subject(s) - chemistry , hydrogen bond , molecule , crystallography , orthorhombic crystal system , intermolecular force , alginic acid , fiber diffraction , helix (gastropod) , x ray crystallography , diffraction , stereochemistry , crystal structure , organic chemistry , ecology , biochemistry , physics , snail , optics , biology
A structural investigation of the marine algal polysaccharide poly‐α‐ L ‐guluronic acid is described. The molecular chains consist of 1 → 4 diaxially linked L ‐guluronic acid residues in the 1C chair conformation and are stabilized in a twofold helix conformation by an intra‐molecular O(2)H … O(6)D hydrogen‐bond. The X‐ray fiber diffraction photograph has been indexed to an orthorhombic unit cell in which a = 8.6 Å, b (fiber axis) = 8.7 Å, c = 10.7 Å. A structure corresponding to the space group P2 1 2 1 2 1 is proposed, in which all intermolecular hydrogen bonds interact with water molecules and in which all oxygen atoms except for the inaccessible bridge oxygens are involed. The relationship between the shape and structure of the polyguluronic acid molecule and its biological function is discussed.