Role of 1-hydroxybenzotriazole in oxidation by laccase from Trametes versicolor. Kinetic analysis of the laccase-1-hydroxybenzotriazole couple.
In the current studies, we used Lineweaver-Burke analysis to examine the role of 1-hydroxybenzotriazole (HBT) in the oxidation of various compounds by laccase from Trametes versicolor. At low concentrations, HBT was a competitive inhibitor of the oxidation, but at high concentrations, it was a noncompetitive inhibitor. Analysis of the oxidation of ferrocytochrome c by the laccase-HBT couple showed that increasing the concentration of ferrocytochrome c did not affect the V(max) but reduced the apparent K(m). In addition, in the manganese peroxidase-Mn(II) reaction, which is a typical oxidation system by mediator, the apparent K(m) and V(max) increased as the concentration of the substrate 2,6-dimethoxyphenol was increased. These results indicate that HBT is involved in the binding of laccase and substrates that laccase cannot oxidize alone.
Hirai
Hirofumi
H
Department of Forest Resources Science, Faculty of Agriculture, Shizuoka University, Shizuoka 422-8529, Japan. afhhirai@agr.shizuoka.ac.jp
Shibata
Hiroshi
H
Kawai
Shingo
S
Nishida
Tomoaki
T
D001487:Basidiomycota / Q000201:enzymology* / Q000378:metabolism; D001667:Binding, Competitive; D045304:Cytochromes c / Q000737:chemistry / Q000378:metabolism; D006139:Guaiacol / Q000737:chemistry / Q000378:metabolism; D007700:Kinetics; D042845:Laccase / Q000737:chemistry / Q000378:metabolism*; D010084:Oxidation-Reduction; D014230:Triazoles / Q000737:chemistry / Q000378:metabolism*
D014230:Triazoles; D006139:Guaiacol; D045304:Cytochromes c; C011852:1-hydroxybenzotriazole; D042845:Laccase