Properties of Drosophila melanogaster prophenoloxidases expressed in Escherichia coli

► Drosophila melanogaster three prophenoloxidases (PPOs) can be expressed in Escherichia coli with different enzyme activity. ► Protein expression conditions: at 16 °C and with Cu2+ added. ► Three rPPOs can be activated by serine protease. ► rPPO1 and rPPO3 have high Cu2+ association capability.