Disaccharide conformational maps: how adiabatic is an adiabatic map?
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Updated: Oct 18, 2026

Modeling Ligands into Maps Derived from Electron Cryomicroscopy
Published on: July 19, 2024
1Departamento de Química Orgánica-CIHIDECAR, Facultad de Ciencias Exactas y Naturales, UBA, Ciudad Universitaria, Argentina. stortz@qo.fcen.uba.ar
Abstract:
The 'adiabatic' (phi, psi) potential-energy surface of the disaccharide alpha-D-galactopyranosyl-(1-->3)-beta-D-galactopyranose was obtained by several established methods, using the MM3 molecular mechanics force field. The constrained minimizations throughout the whole grid were carried out using sharply different dielectric constants. The attainment of the 'true' adiabatic map is very difficult due to the 'multiple minimum problem', originating in the large number of exocyclic pendant groups present in a disaccharide. However, these results suggest that at low dielectric constants, the usual approach starting with conformers carrying cooperative hydrogen bonds results in a good approximation to the true adiabatic map, while at high dielectric constants this approach fails due to the damping of electrostatic and hydrogen-bonding interactions.
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