1.14.13.25 catalase reduction current is enhanced by the presence of catalase ot if the reaction is performed in a flow-cell, probably because O2 is reduced to H2O2, by the hydroxylase component of the enzyme MMOH at the electrode surface and the H2O2 then inactivates the enzyme unless removed by catalase or a continous flow solution 1.14.13.25 additional information contains one axial water which also H-bonds to both side chains of Glu243 and Glu114, and one bidentate carboxylate group from the side chain of Glu144, which is likely to represent the active site of MMOH-Q 1.14.13.25 additional information when the growth-limiting substrate is switched from methane to methanol, in the presence of the particulate MMO inhibitor allylthiourea, growth continues unabated and sMMO activity is completely retained. During the brief period when both methane and methanol are present, higher sMMO activity is observed 1.14.13.25 regulatory protein MMOB the native regulatory protein MMOB is required for maximum enzyme activity