A study on reducing substrates of manganese-oxidizing peroxidases from Pleurotus eryngii and Bjerkandera adusta.
A novel peroxidase, oxidizing Mn2+ and different aromatic compounds, was isolated. Hydroquinones, substituted phenols, dyes, other aromatic compounds and Mn2+ were compared as reducing substrates, and conclusions presented in the light of a molecular model built by homology modeling. The enzymes showed the fastest reaction rates with Mn2+, but the highest affinity corresponded to hydroquinones and dyes. Oxidation of Reactive Black 5 (an azo-dye not oxidized by Mn3+) was non-competitively inhibited by Mn2+. These findings, together with identification of putative Mn-binding site (involving Glu36, Glu40, Asp175 and inner heme propionate) and long-range electron transfer pathways, indicate that different sites are involved in substrate oxidation.
Heinfling
A
A
FG Microbial Ecology, Technical University of Berlin, Germany.
Ruiz-Dueñas
F J
FJ
Martínez
M J
MJ
Bergbauer
M
M
Szewzyk
U
U
Martínez
A T
AT
D001487:Basidiomycota / Q000201:enzymology*; D001665:Binding Sites; D002852:Chromatography, Ion Exchange; D006418:Heme; D006841:Hydrocarbons, Aromatic / Q000378:metabolism; D007700:Kinetics; D008345:Manganese / Q000378:metabolism; D008958:Models, Molecular; D010544:Peroxidases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D011124:Polyporaceae / Q000201:enzymology*; D011487:Protein Conformation; D013379:Substrate Specificity
D006841:Hydrocarbons, Aromatic; D006418:Heme; D008345:Manganese; D010544:Peroxidases; C051129:manganese peroxidase