PEG-modified Penicillin Acylase and Its Partitioning in Aqueous Two-phase Bioconversion System

Polyethyleneglycol (PEG) activated by tosyl chloride was used to modify penicillin acylase (PAC). The stability of the PEG PAC was much better than the free PAC. The activity of the modified enzyme was 75% of free enzyme. The partition of PEG PAC in aqueous two phase system was investigated. The modified penicillin acylase was mainly present in the PEG phase in a PEG dextran aqueous two phase system, and the partition coefficient was 25.