Figure A1.

Contoured 2D $\varphi$, $\psi$ PMF surfaces for disaccharide in the gas phase illustrate the range of motion possible for an unrestrained linkage: $\alpha$DMan(1→3)$\alpha$DMan (left); $\beta$DGlc(1→2)$\alpha$DMan (middle); and $\beta$DXyl(1→2)$\alpha$DMan (right). Contours are drawn at intervals of 1 kcal.mol⁻¹ to a maximum of 12 kcal.mol⁻¹. The $\beta$(1→2) PMF maps are annotated with the $\varphi$, $\psi$ regions associated with the (i) major “face-on” and (ii) minor “side-on” linkage orientations. The insets show schematics of the relative rotations of the glycosidic rings in these two orientations.