... proteasome)serumA portion of the purified rice 20S proteasome fraction(3 mg ) was dialyzed against 50 mMpotassium phosphatebuffer, pH 7.5, and t he protein s olution was co ncentrated to1mgÆmL)1. ... mixed with equalvolume of binding/washing buffer containing 140 mMNaCl, 8 mMNa2PO4,2mMpotassium phosphate and1mMKCl, pH 7.4, and loaded onto HiTrap r Protein A FF1 m L (Amersham...