Fig. 4

Purification of 1, 2 catechol dioxygenase using anion exchange/size exclusion chromatography on a Sephadex A-50 column from (A)P. putida and (B) expressed E. coli. Proteins from a crude bacterial culture that were 50–70% (NH₄)₂SO₄ saturated were added to a column (802 cm) that had been equilibrated with 0.05 M phosphate buffer (pH 7.0). With a gradient of 0–1 M of NaCl and a flow rate of 1 mL/min, elution was performed