Comparison of effects of potassium iodide and potassium chloride on structure and physicochemical properties of proteins

The effects of KI (1.25, 6.25, 12.50 mM) on the structure and physicochemical properties of proteins (bovine serum albumin, ovalbumin, and lysozyme protein) at the corresponding pH values were investigated. The results showed that the interaction of I- with protein molecules was significantly stronger than that of Cl- under different concentration conditions. The higher the concentration, the more pronounced the interaction was by turning potassium iodide into potassium iodate, which bound to proteins in a more stable form, and the conformational changes of protein molecules were more remarkable. At high concentrations, the hydrodynamic radii of the bovine serum albumin and ovalbumin proteins increased significantly, up to 20.97 % and 157.95 %, respectively, and affected the microrheological behavior of the system, weakened the tracer particle motion and the elasticity of the system, changed the microenvironment in which the particles were located, with significant changes in the secondary structure of their amide I bands. Overall, there was no significant effect on lysozyme proteins. This study offers new directions for physiological mechanisms and promotes the development and application of food products.