PARTITION-COEFFICIENTS OF ALPHA-AMYLASE IN AQUEOUS 2-PHASE SYSTEMS PEG-CENTER-DOT-7H(2)O+H2O AT 298K(MGSO4)

Partition coefficients of alpha-amylase have been determined in a poly ethylene glycol (average molecular mass 8000)/MgSO4 . 7H(2)O aqueous t wo-phase system at 298K and the influence of polymer, salt and initial enzyme concentration on partition was investigated. Correlations are proposed which relates the partition coefficient to the initial enzyme concentration and the concentration difference between phases of poly mer and salt. The free volume change, related to the densities of the separate phases, has a direct dependence with such polymer and salt co ncentration differences, respectively, and is then used to facilitate future estimations. Thus, the partition coefficient is a function of t his physical parameter and the initial enzyme concentration employed ( 1.25, 2.50 and 5.00 g dm(-3)). (C) 1998 Elsevier Science B.V.