2.1.1.204 - 2.1.1.204 recombinant GST-tagged enzyme from Escherichia coli strain BL21(DE3) by ultracentrifugation, glutathione affinity chromatography, and tag cleavage through PreScission protease, followed by heparin affinity chromatography, gel filtration, and ultrafiltration 2.1.1.204 recombinant His-tagged enzyme from Escherichia coli strain Rosetta2 (DE3) by nickel affinity chromatography and dialysis 2.1.1.204 recombinant His6-tagged wild-type and mutant enzymes from Escherichia coli strain BL21(DE3) 2.1.1.204 recombinant His6-tagged wild-type and mutant enzymes from Escherichia coli to over 90% purity, except for mutant R84A, which is about 75% pure