Abstrakt

Mechanism studies on the interaction of Gemini surfactant 12-6-12 with bovine serumalbumin by fluorescence method

Mengyao Hu, Xue Wang, Ling Li, Yu He, Gongwu Song

The mechanism of the interaction between hexamethylene-1, 3-bis (dodecyldimethylammoniumbromide) (Gemini 12-6-12) and bovine serum albumin was investigated by fluorescence spectroscopy. The results showed that the fluorescence quenching of BSA by 12-6-12 was attribute to the formation of the 12-6-12–BSA complex. Site marker competitive experiments demonstrated that the binding of 12-6-12 to BSAprimarily took place in site I of BSA. The enthalpy change (ÄH) and entropy change (ÄS) were calculated to indicate that hydrophobic forces and hydrogen bond were the dominant intermolecular force in stabilizing the complex. Steady-state fluorescence indicates the strong interation between surfactant and BSA when the concentration of 12-6-12 is higher than the critical micelle concentration. The effect of 12-6-12 on the conformation ofBSAwas also analyzed by synchronous fluorescence spectrometry and TEM.