The Interaction of Fungal Laccase with Hydrogen Peroxide and the Removal of Fluoride from the Inhibited Enzyme

Electron paramagnetic resonance analysis shows that H2O2 added to native fungal laccase binds to one specific Cu2+ of the four copper atoms in the enzyme (the so‐called Type 2 or “nonblue” Cu2+). This binding of H2O2 is associated with a new absorption band in the visible and nearultraviolet spectrum of the enzyme with its maximum absorbance at 400 nm. Fluoride bound to Type 2 Cu2+ of the enzyme, as commonly prepared, can easily be removed by dialysis of the reduced enzyme. Presence of H2O2 in this dialysis makes the removal of fluoride faster.