Elucidation of binding sites for protein denaturation by surfactant

One of the most important lessons that can be learned from studies of prote in-surfactant interaction is that the details of the process reflect the de tailed tertiary structures of the proteins. The binding of ionic surfactant s to different water-soluble proteins; urease, peroxidase, human serum albu min and amino acid oxidase, were extensively studied by equilibrium dialysi s and isothermal titration microcalorimetry techniques. The electrostatic i nteraction, which is accompanied by a preliminary hydrophobic interaction, occurs initially and is followed by a more extensive pure hydrophobic inter action The predominant unfolding of a protein is related to the first inter action, in which neutralization of charges at the surface of the protein pe rturb the balance of forces in the protein structure. The number of binding sited in the first set gl, is markedly consistent with concentration at mi dpoint of denaturation profiles and very close to the sites at the surface of the single subunit protein with opposite charge with respect to the ioni c head group of surfactant.