NMR Investigation of the Bound Conformation of Natural and Synthetic Oligomannosides to Banana Lectin

The conformational behaviour of three mannose-containing oligosaccharides, namely, the $\alpha1 \rightarrow 3[\alpha1 \rightarrow 6]$ trisaccharide, a heptasaccharide with $\alpha1 \rightarrow 2$, $\alpha1 \rightarrow 3$ and $\alpha1 \rightarrow 6$ linkages and a tetrasaccharide consisting of $\alpha1 \rightarrow 3$ and $\alpha1 \rightarrow 2$ linkages, when bound to banana lectin (BanLec) has been evaluated by trNOE NMR methods and docking calculations. It was found that the molecular recognition event involves a conformational selection process with only one of the conformations present in the free state of the sugar being recognised at the lectin binding site.