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

The interaction between a homologous series of nalkyl trimethyl ammonium br omides and lysozyme was studied by a potentiometric method using a surfacta nt-selective electrode. The binding isotherms the interaction between a hom ologous series of nalkyl trimethyl ammonium bromides were measured for diff erent conditions and show a concentration dependence attributable to aggreg ation of the lysozyme-surfactant complexes. The binding isotherms are discu ssed in terms of the binding potential concept of Wyman and are used to cal culate an apparent Gibbs energy of binding per surfactant cation. The bindi ng isotherms show that the C-1 decreases with increasing chain length of su rfactant.