Figure 4.

Time course of chitin degradation. SmLPMO10A, ScLPMO10C WT, and the three chitin-active ScLPMO10C variants M2, M5, and M18 were incubated at 1 μm with 10 g/liter β-chitin at 40 °C and pH 6.0 in the presence of 1 mm ascorbic acid (reducing agent) for 4 h. A chitinase (SmChiC) was also added at 0.25 μm to obtain more rapid solubilization of LPMO-generated chain ends from the insoluble substrate. The reaction was stopped by vacuum filtering, and the soluble oxidized products were converted to oxidized dimers by treatment with chitobiase prior to analysis. All reactions were performed in triplicate. The error bars show ± S.D. (n = 3).