Participation of Mn(II) in the catalysis of laccase, manganese peroxidase and lignin peroxidase from Phelbia radiata.
Oxidation capacities of laccase, manganese peroxidase (MnP) and lignin peroxidase (LiP) from Phlebia radiata were compared using non-phenolic (veratryl alcohol and ABTS) and phenolic (syringaldazine, vanillalacetone and Phenol red) compounds as reducing substrates. The effect of Mn(II) on enzyme reactions was also studied. Highest specific activities were recorded with laccase in the oxidation of phenolic compounds or ABTS and irrespective of Mn(II) concentration. LiP and MnP oxidized all these substrates but only the catalysis of MnP was dependent upon Mn(II). Only LiP clearly oxidized veratryl alcohol. However, Mn(II) interfered with this reaction by repressing veratraldehyde formation. These results point to multiple participation of manganese ions, either as a reducing (Mn(II)) or oxidizing (Mn(III)) agent in the enzymatic reactions.
Department of Applied Chemistry and Microbiology, University of Helsinki, Viikki, Finland.
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Lundell
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Hatakka
D052160:Benzothiazoles; D002384:Catalysis; D005658:Fungi / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D007700:Kinetics; D042845:Laccase; D008345:Manganese / Q000494:pharmacology*; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000378:metabolism*; D010544:Peroxidases / Q000378:metabolism*; D010636:Phenols / Q000378:metabolism; D013451:Sulfonic Acids / Q000378:metabolism
D052160:Benzothiazoles; D007202:Indicators and Reagents; D010636:Phenols; D013451:Sulfonic Acids; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; D008345:Manganese; D010088:Oxidoreductases; D042845:Laccase; D010544:Peroxidases; C042858:lignin peroxidase; C051129:manganese peroxidase