Behaviour of bovine serum albumin in aqueous solutions of some sodium salts of organic acids, tetraethylammonium bromide and dextrose investigated byultrasonic velocity, viscosity and density measurements

Ultrasonic velocity (u), viscosity (eta) and density (rho) of aqueous solut ions of disodium Succinate (DSS), trisodium citrate (TSC), disodium ethylen ediaminetetraacetate (DSEDTA), tetraethylammonium bromide (TEAB) and dextro se (DT) have been measured in the concentration range 0.01 to 0.40 mol dm(- 3) at 308.15 K. Such measurements have also been made at different concentr ations of these salts and DT in 0.02 g cm(-3) aqueous bovin serum albumin ( BSA) and also at varying concentrations of BSA in the range 0.003 to 0.040 g cm(-3) in 0.1480 mol dm(-3) solution of these salts or DT in water. The i sentropic compressibilities (K-s) of all the solutions have been calculated from the relation: K-s = 1/u(2)p. The isentropic compressibility contribut ion (Delta K-s) and viscosity contribution (Delta eta) due to BSA in variou s salt solutions as well as in pure water have been calculated at different concentrations of the protein and plotted against BSA concentration (C). T he results show that BSA interacts strongly with all these salts and DT. TE AB, TSC and DT stabilize the protein by interaction at all BSA concentratio ns. At low concentrations of BSA, 0.1480 mol dm(-3) DSS, TSC and DSEDTA den aturate or dissociate (destabilize) the protein by interaction. At high con centrations of protein only DSEDTA denaturates or dissociates the protein w hile all other salts and DT have stabilizing effect.