β-Lactose in the View of a CFF-Optimized Force Field

Publisher Website
Google Scholar
Abstract
A recently developed force field PEF95SAC, based on Consistent Force Field (CFF) optimized potential energy parameters for alcohols and most of the naturally occurring carbohydrates, is applied to and tested on β-lactose. The properties of the potential energy surface of this disaccharide are compared to X-ray structures, NMR coupling constants and optical rotation data. The overall performance indicates good extrapolative power for the modeling of oligo- and polysaccharide structures. A new glycosidic linkage geometry region is proposed for β-lactose as being important in both solid state and water solutions. This finding is supported by calculated J H,C coupling constants and calculated optical rotation values. In relation to the spectral calculations on β-lactose, the error of the use of relative energies (ΔE) in place of the Gibbs free energy (ΔG) as the basis for calculating Boltzmann distributed properties is demonstrated. In the β-lactose case it is shown that the conformational entropy is neither negligible nor uniformly distributed over the potential energy surface.

This publication has 21 references indexed in Scilit: