MM3 Potential energy surfaces of β-4-linked mannobiose and mannotriose at different dielectric constants

• Autores: Stortz, C.A.
• Año de publicación: 2005
• Idioma: inglés
• Tipo de recurso: artículo
• Fuente: Arkivoc 2005;2005(12):22-35
• Materia: Conformational analysis; Mannan; Mannobiose; MM3; Potential energy surface; Trisaccharides
• Institución: Universidad Nacional de Buenos Aires. Facultad de Ciencias Exactas y Naturales

The adiabatic potential energy surface (PES) of β-4-linked mannobiose was obtained using the MM3 force field at ε=3 and ε=80, and plotted as contour maps and as 2D graphs representing the energy vs. the ψ angle. The surfaces of the corresponding trisaccharide were also obtained and represented by a single 3D contour map for which the energy is plotted against the two ψ glycosidic angles. The PES of the disaccharide contains a low-energy well comprising two different minima, and three more minima in different locations. No major change was observed by changing the dielectric constant. For the trisaccharide, four main minima were observed, located within one minimum-energy region. The minima have a geometry close to that experimentally obtained for mannobiose, mannotriose and mannan I in solid state, but differ from that expected in aqueous solutions. The flexibility of the glycosidic linkage increases at higher dielectric constant, whereas it decreases for the linkage closer to the reducing end when passing from the di- to the trisaccharide. ©ARKAT.
Fil:Stortz, C.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.