title: Conformational analysis of the anomeric forms of kojibiose, nigerose, and maltose using MM3.
abstract: Energy surfaces were computed for relative orientations of the relaxed pyranosyl rings of the two anomeric forms of kojibiose, nigerose, and maltose, the (1----2)-alpha, (1----3)-alpha, and (1----4)-alpha-linked D-glucosyl disaccharides, respectively. Twenty-four combinations of starting conformations of the rotatable side-groups were considered for each disaccharide. Optimized structures were calculated using MM3 on a 20 degree grid spacing of the torsional angles about the glycosidic bonds. The energy surfaces of the six disaccharides were similar in many respects but differed in detail within the low-energy regions. The maps also illustrate the importance of the exo-anomeric effect and linkage type in determining the conformational flexibility of disaccharides. Torsional conformations of known crystal structures of maltosyl-containing molecules lie in a lower MM3 energy range than previously reported.
authors.affiliation: Department of Chemical Engineering, Iowa State University, Ames 50011.
authors.forename: M K
authors.initials: MK
authors.lastname: Dowd
authors.forename: J
authors.initials: J
authors.lastname: Zeng
authors.forename: A D
authors.initials: AD
authors.lastname: French
authors.forename: P J
authors.initials: PJ
authors.lastname: Reilly
mesh_terms: D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D004187:Disaccharides / Q000737:chemistry*; D005936:Glucans / Q000737:chemistry*; D007536:Isomerism; D008320:Maltose / Q000737:chemistry*; D008969:Molecular Sequence Data; D013329:Structure-Activity Relationship
chemical_list: D004187:Disaccharides; D005936:Glucans; C014637:laminaribiose; D008320:Maltose; C008237:kojibiose