(a) Effect of H-bonding network substitutions on MtPMO3* PASC activity. Assays contained 2 µM PMO, 10 mg mL−1 PASC, atmospheric O2, and 1 µM MtCDH-2 as the reducing agent. Reactions of 45 µL were carried out in 50 mM sodium acetate buffer (pH 5.0) at 40 °C for 1 min. Peaks from aldonic acids with DP 5–13 were quantified via HPAEC with electrochemical detection (nC), and peak areas were integrated over time (nC·min). Smaller C1-oxidized products with DP 2–4 were excluded from this analysis, as they are also products of the CDH reaction (n = 3). (b) Sample HPAEC trace with aldonic acid products labeled by DP, from A2-A13.