Changes in shape and size of the stiff branched β-glucan in dimethlysulfoxide/water solutions

The conformation transition of the short branched β-glucan AF1 isolated from Auricularia auricula-judae in DMSO/water solutions was investigated with viscometry and static/dynamic light scattering (SLS/DLS). AF1 in the mixed solution exhibited a sharp decrease in viscosity and molecular size in a narrow DMSO volume fraction (vDMSO) range of 0.80-1.0. It indicated that the stiff AF1 transformed into flexible chains probably, resulting from the destruction of intra- and inter-molecular hydrogen bonds of the polysaccharides. AF1 solutions with dialyzed treatment gave a more narrow transition range of 0.90-1.0. The conformation transition of AF1 was further conformed by transition electron microscopy (TEM) and atomic force microscopy (AFM). The multiple hydrogen bonds of polysaccharides affect the chain conformation, which in turn affect the application in food and pharmaceutical fields.