The second method of purification used the commercially available MagneHis Protein Purification System (Promega, Madison, WI) according to the manufacturer's instructions. For that, 50 ml of IVTT reaction was mixed with 700 ml of Binding Buffer (100 mM HEPES, 20 mM Imidazole and 8 M Urea pH 7.5) and incubated at 4uC for 20 min in an orbital mixer, to solubilize the inclusion bodies. Then, 30 ml of MagneHis Niparticles was added to the sample and the mixture incubated at room temperature for 2 min. The sample tubes were connected to the MagneSphere Magnetic Separation Stand (Promega) and, after 30 sec of binding, the flow through was removed and discarded. The magnetic beads with bound protein were washed 3 times with 700 ml of Binding Buffer and the recombinant eluted in 200 ml of Elution Buffer (100 mM HEPES, 500 mM Imidazole and 8 M Urea pH 7.5) incubated at 4uC for 20 min in an orbital mixer before collection.