Fig. 4

Effect of H₂O₂ on the degradation of PASC by LPMO. a Sequential titration of 20 µM (green line), 40 µM (red line) or 80 µM (blue line) H₂O₂ to a solution containing 0.8 mg mL⁻¹ PASC, 3 µM LPMO and 2 mM ascorbate. The background reaction of LPMO in the presence (black line) or absence (grey line) of 2 mM ascorbate. b Time-dependent, electrochemical measurement of H₂O₂. All reactions were carried out at a volume of 12 mL under constant stirring at 30 °C and contained 0.8 mg mL⁻¹ PASC in 50 mM sodium phosphate buffer, pH 6.0. Vertical dotted lines indicate the addition of fresh H₂O₂ which was added approximately every 90 s in aliquots of 40 µM. Shown is the addition of H₂O₂ to PASC (black line); PASC and 3 µM LPMO (green line); PASC and 2 mM ascorbate (magenta line); PASC, 2 mM ascorbate and 3 µM LPMO (red line). In an additional experiment, PASC, 2 mM ascorbate and 3 µM LPMO was supplemented with 80 µM H₂O₂ per addition (blue line). c Degradation of 0.8 mg mL⁻¹ PASC by 3 µL LPMO. H₂O₂ (40 µM) was sequentially added to the samples every 90 s in presence or absence of 2 mM ascorbate. The total amount of added H₂O₂ was 400 µM