Mono Q-Sepharose anion-exchange chromatography
The active fractions from Sephadex G-100 were applied to a
Mono Q-Sepharose column (2 cm 10 cm) previously equilibrated
with buffer C (25 mM Tris–HCl, pH 8.0). After being washed with
the same buffer, until A280 was below 0.05, bound proteins were
eluted with a linear gradient of sodium chloride in the range of
00.5 M in the equilibrating buffer. Fractions of 5 mL were collected
at a flow rate of 70 mL/h and analysed for protease activity
and protein concentration.