Purification and characterization of recombinant single-chain urokinase produced in Escherichia coli

Recombinant single-chain urokinase (rUK1) has been purified from Escherichia coli. The purification utilizes a refractile body purification, followed by batch DE-52 cellulose extraction, hydroxylapatite chromatography, and S-200 chromatography. Two-chain rUK (rUK2) is separated from rUK1 on benzamidine--Sepharose. The purification eliminates proteases early in the procedure so the rUK1 will not be cleaved to rUK2. The rUK1 has been characterized by amino-terminal analysis as well as carboxy-terminal analysis after cleavage by plasmin.