Gemini surfactant-protein interactions: effect of pH, temperature, and surfactant stereochemistry.

The interactions between bovine serum albumin (BSA) and gemini surfactants derived from cystine have been investigated and were compared with the conventional single-chain surfactant derived from cysteine. The influence of the stereochemistry of the gemini surfactant on its behavior toward BSA was also investigated, as well as the effects of pH and temperature. Electrical conductivity and surface tension measurements were used to obtain important system parameters such as critical aggregation concentration (cac), polymer saturation point (psp), degree of ionization (alpha), and the amount of surfactant binding to protein (M). Stereochemistry was found to influence the surface properties of the surfactants studied and their interaction with BSA but not their micellar properties in solution.