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

Abstract

Electron paramagnetic resonance analysis shows that H 2 O 2 added to native fungal laccase binds to one specific Cu 2+ of the four copper atoms in the enzyme (the so‐called Type 2 or “nonblue” Cu 2+ ). This binding of H 2 O 2 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 Cu 2+ of the enzyme, as commonly prepared, can easily be removed by dialysis of the reduced enzyme. Presence of H 2 O 2 in this dialysis makes the removal of fluoride faster.