Equilibrium dialysis studies on the binding of anionic surfactants with bovine milk casein

The binding process of amphiphile molecules with proteins depends on the experimental conditions, such as protein concentration and surfactant type. The proteins may have different binding characteristics, such as specific and cooperative binding. Specific binding is the most important pathway observed at low surfactant concentration at levels of micromolar unity, while the cooperative process becomes the most important at higher surfactant concentration, close to the critical aggregation concentration. At the levels at which specific binding occurs there is competitivity, i.e., the presence of an additional molecules can be induced hydrophobically or electrostatically depending on the characteristics of the molecular structure and experimental conditions. For instance, electrostatic binding is pH dependent and this factor is important for ionic surfactants.