Thermal Stability Of Triple Helix Research Articles

A differential scanning calorimetric study of the conformat ional transitions of several kinds of (1→6) branched (1→3)-β-d-glucans in a mixture of water and dimethylsulfoxide

The thermal conformational transitions of seven kinds of (1→6) branched (1→3)- β-D-Glucans were comparatively studied in a water-dimethylsulfoxide mixture containing 16.47 weight % of water by high-sensitivity differential calorimetry(DSC). The DSC curves for schizophyllan, scleroglucan, and PS-1426 glucan, showed two endothermic peaks which were assigned to an internal change of triple helix and a triple helix-single coil transition, respectively. The differences in transition temperature and enthalpy of the transitions between these glucans suggested the variation of the thermal stability of triple helix of this type of glucans. It was found that the transition temperatures are correlated to the degree of branching for these glucans, suggesting that the side chain glucose contributes to the thermal stability of triple helix of (1→6) branched (1→3)- β-D-glucans. The glucans (T-4-N and T-5-N) isolated from fruit bodies of Dictyophora indusiata yield multiple peaks in the DSC curves, suggesting the heterogeneity in composition of 'the samples.