Porcine pancreatic lipase partition in potassium phosphatepolyethyleneglycol aqueous two-phase systems
BASSANI, GEORGINA; FARRUGGIA, BEATRIZ; NERLI, BIBIANA; ROMANINI, DIANA; PICÓ, GUILLERMO
Journal of Chromatography B
Lugar: Amsterdam; Año: 2007 vol. 859 p. 222 - 228
This research study examined porcine pancreatic lipase partition in aqueous two-phase systems formed by polyethylene glycol-potassium phosphate at pH 6.0, 7.0 and 8.0, the effect of polymer molecular mass, and NaCl concentration. The enzyme was preferentially partitioned into the polyethylene glycol rich phase in systems with molecular mass 40008000, while with polyethylene glycol of 10,000 molecular mass it was concentrated in the phosphate rich phase. The enthalpic and entropic changes found due to the protein partition were negative for all the polyethylene glycol molecular mass systems assessed. Both thermodynamic functions were shown to be associated by an entropicenthalpic compensation effect suggesting that the water structure ordered in the ethylene chain of polyethylene glycol plays a role in the protein partition. The addition of NaCl increased the lipase affinity to the top phase and this effect was most significant in the system polyethylene glycol 2000NaCl 3%. This system yielded an enzyme recovery more than 90% with a purification factor of approximately 3.4.