Effect of neutral carbohydrate structure in the set glucose/sucrose/maltodextrin/dextran on protein surface activity at the air/water interface

This paper presents the effect of neutral carbohydrates with different structure in the set glucose/sucrose/maltodextrin (DE-10)/dextran (mol. wt = 70 kDa) on 11S globulin surface activity al the planar air/water interface under a low ionic strength (I = 0.01 mol/dm(3)) in aqueous medium at neutral pH (7.0). The surface pressure was found to show a dramatic dependence on the concentration of the low-molecular-weight sugars. In the case of high-molecular-weight carbohydrates, the role of the excluded volume effect on the protein surface activity seems to become prevailing under the experimental conditions pH 7.0, I = 0.01 mol/dm(3). The alterations in protein surface activity correlate well with change in the protein thermodynamic affinity (estimated by the light scattering method) for the aqueous medium in the presence of neutral carbohydrates.