Interactions between bovine serum albumin and gemini surfactant alkanediyl‐α, ω‐bis(dimethyldodecyl‐ammonium bromide)

Interactions between bovine serum albumin (BSA) and cationic gemini surfactant alkanediyl‐α,ω‐bis(dimethyldodecyl‐ammonium bromide) (12‐n‐12, n = 3, 4, 6) in aqueous solution have been investigated by measuring fluorescence, UV‐vis transmittance, dynamic lighting scattering, and circular dichroism. Compared to a traditional surfactant dodecyltrimethylammonium bromide (DTAB), 12‐n‐12 interacts with BSA more strongly. With increasing concentration, 12‐n‐12 first binds specifically onto BSA leading to the unfolding and aggregation of BSA, and the decrease in α‐helix content; and then forms micelle‐like complexes along the unfolded BSA chains. A gemini surfactant with a longer spacer has a larger effect on BSA unfolding due to a stronger hydrophobic interaction. © 2006 Wiley Periodicals, Inc. Biopolymers 83:243–249, 2006 This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com