Conformation and Dynamics of (1→3)-β- D -Glucans in the Solid and Gel State

Gel network of (1 → 3)-β-d-glucans turned out to be highly heterogeneous from its motional state, from liquid-like, through intermediate, to solid-like domains. They were analyzed by a variety of NMR experiments. We found that conformations of these domains in a gel of a linear glucan (curdlan) exhibits an identical single helix conformation with a low proportion of a triple helix with reference to the data obtained in the solid state. Cross links of curdlan gel are thus ascribed to the triple helical junction as well as pseudo-cross-links formed by association of the single helical chains. In contrast, it was found that the network structure of branched glucans arose mainly from the triple helical chains. Gelation of the branched glucans thus proceeds from partial association of the triple helical chains.