The insoluble fraction of the lysate was
removed by centrifugation at 47,000 g for 30 min at 4 C, and the
supernatant was filtered through a 0.2 mm pore-size filter and then
loaded onto a Talon Superflow resin (Clontech) equilibrated in
phosphate buffer (50 mM, pH 7) containing 300 mM NaCl and
10 mM imidazole to improve the interaction specificity in the affinity
chromatography step. The bound enzyme was eluted using
phosphate buffer (50 mM, pH 7) containing 300 mM NaCl and
150 mM imidazole.