The DNase was added to the cell culture (20 μg/ml) after defrosting from -80°C. The culture was sonicated (Sonic Dismembrator Model 705 Fisher Scientific, USA) in 6 x 2-minute cycles with a 50 % amplitude (5 s pulse, 5 s pause). The cell suspension was centrifuged (21036 g, 4°C, 1 h) using a Sigma 6-16K centrifuge (SciQuip, UK) equipped with the 12166 rotor. 1 liter of cell-free extract was divided into two 50 ml conical centrifuge tubes with washed Resin (TALON® Superflow Metal Affinity Resin, Takara). The mixture was incubated for 1.5 hours at 4°C on a roller (40 rounds/min). After incubation, the resin with bound proteins was centrifuged in a pre-cooled centrifuge for 10 min, 130 g, 4°C using a Sigma 2-16K centrifuge (SciQuip, UK) equipped with the 11192 rotor. The supernatant was discarded, and harvesting buffer A (16.4 mM K2HPO4, 3.6 mM KH2PO4, 400 mM NaCl, 10 mM imidazole, pH 7.5) was added and transferred to a gravity-flow column equilibrated in the same buffer. The column with mixture resin protein was washed with approximately 200 ml of harvesting buffer A, and a 50 mM phosphate buffer (pH 7.5) was gradually added to the column. The protein was eluted from the resin using an elution buffer of 50 mM phosphate buffer, 300 mM imidazole (pH 7.5).