LIGHT-SCATTERING, ELECTROPHORESIS, AND TURBIDIMETRY STUDIES OF BOVINE SERUM-ALBUMIN POLY(DIMETHYLDIALLYLAMMONIUM CHLORIDE) COMPLEX

Complexation between bovine serum albumin (BSA) and poly(dimethyldiallylammonium chloride) (PDMDAAC) was studied by static and quasi-elastic light scattering (QELS), electrophoretic light scattering, and turbidimetric titration in dilute electrolyte solution. Both QELS and turbidimetric titration show that complexation occurs at pH > 4.6. The structure of the BSA-PDMDAAC complex in excess protein solution at ionic strength 0.01 M and pH 7.88 depends on the polymer concentration. At low polymer concentration, an intrapolymer complex saturated with BSA is formed. This intrapolymer complex aggregates to interpolymer species upon increase in the polymer concentration.