Figure 3.

SDS-PAGE analysis of purified PpAOS1 (A), PpAOS2 (B) and PpHPL (C). All enzymes were expressed as His-tagged proteins and purified via Ni²⁺-affinity chromatography. Note that different fractions of final elution employing a linear gradient with increasing imidazol concentration are shown in (B) and (C). In case of PpAOS2-purification we applied an additional washing step, in which we washed the column with 50 mM sodium phosphate buffer (pH 8.0) containing 50 mM NaCl, 500 mM urea and 15 mM imidazol in order to further elute unspecifically bound proteins as shown in (B).