In this work, the partitioning of phenylalanine ammonia-lyase was investigated in different systems of PEG1000, PEG2000, PEG3350, PEG6000 and PEG8000 with (NH4)2SO4, Na2SO4, Na2CO3 and potassium phosphate. The results showed that the partition of phenylalanine ammonia-lyase in PEG/salt aqueous two-phase systems was mainly influenced by hydrophobicity, excluded volume effect and salting-out effect; compared with other PEG/salt systems, PEG1000/Na2SO4 was the most effective for phenylalanine ammonia-lyase partitioning. The result further supports that PEG/salt
aqueous two-phase system provides a new and applicable route for the purification of phenylalanine ammonia-lyase, as shown in our published paper.1
