The Conformation of the Trisaccharide and Tetrasaccharide Produced in the Hydrolysis of Barley Glucan with the Enzyme Endo-1,3-1,4-beta-glucan 4-glucanohydrolase From Bacillus-licheniformis

The solution conformation of the tri- and tetrasaccharide obtained by enzymatic degradation of glucan has been analysed using molecular mechanics and dynamics calculations and nuclear magnetic resonance data. The overall shape of both compounds is fairly similar and may be described by an equilibrium formed by conformers included in the low energy regions for both glycosidic linkages. The interglycosidic torsion angles for these conformers are Phi(H)=15+/-45 degrees and Psi(H)=-20+/-30 degrees for both beta(1->4) linkages and Phi(H)=40+/-15 degrees and Psi(H)=-20+/-35 degrees for the corresponding beta(1->3)-linked moiety.