Measurement and correlation of partition coefficients of urokinase in aqueous two-phase PEG-potassium phosphate system

Partition coefficients of Urokinase (UK) were measured in aqueous two-phase systems containing polyethylene glycol and potassium phosphate at 273.2 K. Based on the Diamond-Hsu model, a modified expression was obtained for the correlation of enzyme partitioning in the above-mentioned systems. Utilizing a modified form, the partitioning data of UK and heteroprotein were correlated. The results show that the modified model is simple, gives good precision, and will facilitate engineering scale-up of aqueous two-phase systems for certain proteins purification.