Partitioning features of bovine tripsin and alpha-chymotrypsin in polyethyleneglycol-sodium citrate aqueous two-phase systems.

TUBÍO GISELA; NERLI BIBIANA; PICÓ GUILLERMO

Journal of Chromatography B

Elsevier Science Ireland Ltd

Lugar: Irlanda; Año: 2007 vol. 852 p. 244 - 249

1570-0232

The partitioning of bovine trypsin and -chymotrypsin ? proteases of similar physico-chemical properties ? in different polyethyleneglycol/sodium citrate aqueous two-phase systems was investigated. The effect of different factors such as polyethyleneglycol molecular weight, pH, tie line length, temperature and the presence of an inorganic salt on the protein partition coefficient were analysed. Both a decrease in PEG molecular weight and an increase in pH led to a higher partition coefficient for both enzymes. Aqueous two-phase systems formed by PEG of molecular weight 3350 and citrate pH 5.2 showed the best separation capability which was enhanced in presence of sodium chloride 3%. The transfer of both proteins to the top phase was associated with negative enthalpic and entropic changes.