Micellization, interaction and thermodynamics behavior of BSA plus SDS mixture in aqua-organic mixed solvent: Influences of temperature and solvent composition

Bovine serum albumin (BSA) interaction with sodium dodecyl sulphate (SDS) in aqueous medium as well as aqua-organic mixed media has been performed using the conductivity measurement technique at several temperatures. The experiments were performed in the temperature range of 298.15-313.15 K with a gap of 5 K. The critical micelle concentration (CMC) and the degree of micelle ionization (alpha) have been computed from the specific conductivity versus the surfactant concentration plot. The CMC values achieved in the present study are dependent on the concentration of BSA, composition of the mixed solvent, and a variation of experimental temperature. For SDS + BSA mixture, an increase of BSA concentration causes a decrease in the values of CMC. Also, the values of CMC of SDS + BSA system in water-organic solvents were found to follow the order: CMCwater-DMF > CMCwater-AN > CMCwater-DMSO > CMCwater. In every case examined, the association of SDS + BSA mixture was spontaneous (negative Delta G(m)(0)) . On the basis of observed Delta H-m(0), and Delta S-m(0) values for the SDS + BSA mixed system, it is expected that an electrostatic, hydrophobic, and ion-dipole interactions are in effect between SDS and BSA species, whereas the enhanced hydrophobic interaction is believed to be the main driving force for the aggregation process. In each the case thoroughly detected, a linear relationship between Delta H-m(0), and Delta(0)(Sm), values was viewed, which is a strong indication in favor of the presence of enthalpy-entropy compensation phenomenon in the overall interaction process. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The interaction between Bovine Serum Albumin (BSA) and Sodium Dodecyl Sulphate (SDS) in aqueous and aqua-organic mixed media was studied through conductivity measurements at different temperatures. The results showed that an increase in BSA concentration led to a decrease in CMC values, and the association of the mixed system was found to be spontaneous.