Physico-chemical properties of the association of cetyltrimethylammonium bromide and bovine serum albumin mixture in aqueous-organic mixed solvents.

Herein, we have investigated the association behavior of bovine serum albumin (BSA) and cetyltrimethylammonium bromide (CTAB) using the conductivity method in H 2 O and H 2 O + organic mixed solvents at different temperatures. The association phenomenon was detected from the deviation of the conductivity changes with enhancing the surfactant concentration and changes of numerous physico-chemical properties, such as CMC , α , β and thermodynamic variables (∆ G 0 m , ∆ H 0 m and ∆ S 0 m). The values of CMC for the CTAB + BSA system in 10 % (v/v) solvents follow the trend: CMC water < CMC water+DMSO < CMC water+AN < CMC water+DX < CMC water+DMF. The interaction of BSA with CTAB is notably influenced due to a change of temperature and extent of hydration of BSA and surfactant. The obtained values of –∆ G 0 m manifest that the association of BSA and CTAB mixture is a spontaneous process, while the values of –∆ G 0 m in presence of 10 % (v/v) aq. organic solvents come out in the given sequence: -∆ G m o (H 2 O + DMSO) > ∆ G m o (H 2 O + DMF) > -∆ G m o (H 2 O + DX) > -∆ G m o (H 2 O + AN). The H-bonding, ion-dipole, along with the hydrophobic interactions, are believed to be the binding interactions between BSA and CTAB in the study media. [ABSTRACT FROM AUTHOR]