Thermodynamic studies of interaction between cationic surfactants and lysozyme using potentiometric techniques

The interaction between a homologous series of nalkyl trimethyl ammonium bromides and lysozyme was studied by a potentiometric method using a surfactant-selective electrode. The binding isotherms the interaction between a homologous series of nalkyl trimethyl ammonium bromides were measured for different conditions and show a concentration dependence attributable to aggregation of the lysozyme-surfactant complexes. The binding isotherms are discussed in terms of the binding potential concept of Wyman and are used to calculate an apparent Gibbs energy of binding per surfactant cation. The binding isotherms show that the C-1 decreases with increasing chain length of surfactant.