Extraction of bovine serum albumin using aqueous two-phase poly (ethylene glycol) – poly (acrylic acid) system

Abstract

The partitioning behavior of bovine serum albumin in a new aqueous two-phase system (ATPS) based on low cost commercial polymers like poly (ethy1ene glycol) (PEG) and poly (acrylic acid) (PAA) has been studied. In this ATPS, PAA and PEG are enriched in the bottom and upper phase, respectively. The influence of <span style="mso-bidi-font-style:italic">molecular weight (MW), tie line length, pH, temperatures and NaCl concentration on the partition coefficient of protein has been studied. <span style="mso-bidi-font-style:italic">The protein partitioning decreases on increasing MW of PEG and temperature, whereas increases with an increasing pH and NaCl concentration. This may be attributed by strong electrostatic interactions between the proteins and polymer as well as excluded volume effects. Protein partitioning is better for PEG4000 at 0^oC, pH 8.0 with 1 M NaCl with a yield 88.8%. The present study indicates that PEG-PAA ATPS may be considered as an interesting alternative for protein purification from the biological suspensions.

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