Adsorption of bovine serum albumin onto polystyrene latex: Effects of coexistent electrolyte anions

Abstract

The effects of coexistent electrolyte anions on the adsorption of bovine serum albumin (BSA) onto polystyrene (PS) latex were investigated. Three electrolyte anions (viz. Cl −, CH 3COO −, and SCN −) were used as the sodium salt. The adsorbability of BSA onto PS latex in both Cl − and CH 3COO − media showed a similar tendency. However, BSA adsorption onto PS latex in SCN − medium especially at a high ionic strength was very different from that in other anions (Cl − and CH 3COO −) media. That is to say, in SCN − medium, the pH at maximum adsorption shifted to a more acidic pH region and the maximum adsorption was greater as compared with those in other anion media. These results were interpreted on the basis of the difference in the binding affinity of those small anions to BSA molecule.