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Relaxed‐residue conformational mapping of the three linkage bonds of isomaltose and gentiobiose with MM3(92)
Author(s) -
Dowd Michael K.,
Reilly Peter J.,
French Alfred D.
Publication year - 1994
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.360340505
Subject(s) - isomaltose , chemistry , conformational isomerism , molecule , stereochemistry , crystallography , computational chemistry , organic chemistry , maltose , sucrose
Abstract Isoenergy surfaces were calculated for the α‐ and β‐anomers of isomaltose and gentiobiose, based on 46,656 conformers for each disaccharide. Low‐energy regions exist for each of the three staggered positions about the C‐5′ C‐6′ bonds, and known crystal structures lie in two of these regions. As expected, the molecular partition function showed greater flexibility for these three‐bond‐linked disaccharides than for comparable two‐bond‐linked structures. A model miniature crystal of gentiobiose accounts for most of the remaining structural differences between the modeled isolated molecule and the crystal structure. Based on models of isolated molecules of isomaltose and gentiobiose, the predicted Boltzmann‐weighted nmr coupling constants were satisfactory, as were predicted optical rotations for gentiobiose. © 1994 John Wiley & Sons, Inc.