requires dehydration before facilitating. Shown is the oxidation of NADPH by SOD1 plus H2O2. The final reaction mixtures contained 0.1 mM NADPH, 0.1 mg/ml SOD1, 20 mM , and 10 mM H2O2, plus 100 mM sodium phosphate at pH 7.4 and at 23°C. Line 1, SOD or H2O2 added as the last component at the arrow; line 2, NaHCO3 added last at the arrow; line 3, as in line 2, except that 0.1 mg/ml carbonic anhydrase was present in the reaction mixture. Note the slow oxidation before the addition of .