FIG. 4.

Purification of R. capsulatus DXPase-A. Samples from each purification step were electrophoresed on a 0.1% SDS–12% polyacrylamide gel and stained with Coomassie blue. Lanes: 1 and 6, molecular mass standards (at 20, 30, 40, 50, 70, and 100 kDa); 2, cell extract of BL21/pFMH30 without IPTG induction (∼40 μg); 3, cell extract of BL21/pFMH30 with IPTG induction (∼70 μg); 4, ammonium sulfate precipitation (∼50 μg); 5, Ni²⁺-silica affinity chromatography (∼9 μg).