Study of Protein Partitioning in Polymer-Salt Aqueous Two-Phase Systems Using Electrolyte-SAFT (E-SAFT) Equation of State

Abstract

The statistical associating fluid theory (SAFT) has been applied to correlate partition coefficients of proteins in polymer-salt aqueous two-phase systems. Accordingly, interactions among the association on the partition coefficients of proteins have been thoroughly studied by the SAFT equation of state. The parameters of the SAFT equation of state (EoS) for pure water were obtained from our previous work. Additionally, the parameters of SAFT for poly (ethylene glycol) with diverse molecular weights were estimated using densities of aqueous polymer solutions. Finally, partition coefficients of proteins in aqueous two-phase systems were investigated. The restrictive primitive mean spherical approximation (RP-MSA) has been used for long-range interactions whereas the parameters of SAFT for proteins were obtained, primarily by utilizing the electrolyte-SAFT (E-SAFT). The results showed that the E-SAFT is capable of accurately correlate partition coefficients of proteins in aqueous two-phase systems.