PROTEIN-POLYSACCHARIDE MIXTURES STRUCTURE OF THE SYSTEMS AND THE EFFECT OF SHEAR STUDIED BY SANS

We present results of a small-angle neutron scattering (SANS) study of a globular protein mixed with a neutral (or charged) polysaccharide, and discuss how the structure is affected by shear. According to SANS measurements, the structures of these mixtures located in the one-phas e region of the phase diagram were heterogeneous, the level of floccul ated particles being greatly dependent on the polysaccharide and the s olvent conditions used. Shearing these types of solutions at low shear rates induced a disruption of the liquid-like short-range order (when it existed) between proteins and a slight anisotropy of the particles indicative of some preferential alignment of proteins in the directio n of flow.