Example 7
1000 ml broth of the Aspergillus oryzae expression strain 90.3 was adjusted to pH 7.0 and filtrated on 0.22 μm PES filter (Thermo Fisher Scientific, Roskilde, Denmark). Following, the filtrate was added 1.8 M ammonium sulphate. The filtrate was loaded onto a Phenyl Sepharose™ 6 Fast Flow column (high sub) (GE Healthcare, Piscataway, N.J., USA) (column volume 60 mL) equilibrated with 1.8 M ammonium sulphate pH 7.0, 25 mM HEPES pH7.0. After application the column was washed with 3 column volumes of 1.0 M ammonium sulphate and the protein eluted following with 5 column volumes of 25 mM HEPES pH 7.0 at a flow rate of 15 ml/min. Fractions of 10 mL were collected and analyzed by SDS-page. The fractions were pooled and applied to a Sephadex™ G-25 (medium) (GE Healthcare, Piscataway, N.J., USA) column equilibrated in 25 mM HEPES pH 7.0. The fractions were applied to a SOURCE™ 15Q (GE Healthcare, Piscataway, N.J., USA) column equilibrated in 25 mM HEPES pH 7.0 (column volume 60 mL). After application the column was washed with 3 column volumes equilibration buffer and bound proteins were eluted with a linear gradient over 20 column volumes from 0-500 mM sodium chloride. Fractions of 10 ml were collected and analyzed by SDS-page, and fractions with the protein were pooled to a final volume of 148 ml. The protein concentration was determined by A280/A260 absorbance.