Comparative study on interaction of bovine serum albumin with dissymmetric and symmetric gemini surfactant by spectral method

The interaction between bovine serum albumin (BSA) with N, N'-bis(dimethylalkyl) ethylammonium dibromide (C12C2Cm, m = 8, 12) was investigated by spectral methods. It can be seen that C12C2C8 and C12C2C12 mainly interact with tryptophan residues of BSA from synchronous fluorescence spectra. Fluorescence, far-UV, and near-UV circular dichrosim spectra of BSA are changed by addition of dissymmetric and symmetric gemini surfactant. For surfactant solution, the polarity of the microenvironment surrounding pyrene is lower while the fluorescence lifetime of it is longer and the microviscosity is higher in the presence of BSA than those in the absence of BSA. But compared with C12C2C12, C12C2C8 has lower binding ability with BSA due to the shorter hydrophobic tail and lower symmetry.