1.1.1.214 form A and form B of the enzyme obtained separated by rupture, centrifugation and column chromatography on DEAE-cellulose and hydroxylapatite 1.1.1.214 recombinant His-tagged enzyme from Escherichia coli strain Rosetta (DE3) by nickel affinity chromatography, and tag cleavage by thrombin, followed by anion exchange chromatography, gel filtration, and dialysis 1.1.1.214 recombinant protein 1.1.1.214 using affinity chromatography on Red-Agarose and several subsequent ion exchange steps