Die Phenoloxydasen des Ascomyceten Podospora anserina

Summary

Laccase of the wild strain of Podospora anserina was purified by subsequent treatment with protamine sulfate, precipitation with ammonium sulfate and column chromatography on DEAE-Sephadex and hydroxylapatite. The purity was confirmed by sedimentation and electrophoresis (molecular weight about 361 000, isoeletric point at pH 5.1).

The blue-coloured pure laccase has its absorption-maxima at 280 and 605 mμ. The substrate specifity of the enzyme corresponds to results which have been earlier obtained with unpurified preparations (Esser 1963 b). Laccase is very temperature sensitive. It loses its activity after both freezing and heat treatment (half-life time at 60°C about 6 min). The Michaelis-constants as determined with Dopa, potassium ferrocyanide and catechol are in the range of 2 to 5·10^-3 Mol/l. The appropriate value for ascorbic acid is about 10^-2 less. The laccase contains about 12% carbohydrate and about 7,5% nitrogen. According to its copper content of 0.123% the laccase carries seven atoms of copper per molecule.