Constitution and Properties of Laccase

Abstract

IT was shown that laccase, which had been inactivated by cyanide under certain conditions, could be almost completely re-activated by cupric ions, whereas other metals were ineffective¹. Further evidence will be presented here to show that copper is an essential constituent of this enzyme. Laccase was purified by the method of D. Bertrand^2,3. At each successive stage of purification the enzyme activity was measured in the manner previously described¹, and copper and manganese were estimated by microchemical methods^4,5. Manganese disappears after the first steps of purification; the copper content increases with the $Q_{{\text{O}}_{\text{2}}}$ and remains proportional to activity in all fractions up to the purest preparation having $Q_{{\text{O}}_{\text{2}}}$ 30,000 in presence of paraphenylene diamine (Fig. 1).