Figure 3. Heterologous expression of ToPPO-2. A Purification via Strep-Tactin-affinity chromatography.

SDS-PAGE analysis was performed and proteins were stained by Coomassie Brilliant Blue. M: protein standard; ce: crude extract; ft: flow-through fraction; e: elution fraction. B PPO-kinetics on 4-methylcatechol. An example of a typical curve is shown. Non linear regression to the Michaels-Menten equation was performed (R² = 0.99) to gain values for v_max (0.14±0.004 µkat per purified PPO; dotted line) and K_m (0.62±0.07 mM).