Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.10.3.2 (laccase)
 4,656 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Under secondary metabolic conditions, the white-rot basidiomycete Coriolus versicolormetabolized 4-methyldibenzothiophene (MDBT), which is a recalcitrant organic sulfur contaminant found in petroleum. The pathway of the transformation of MDBT was elucidated by the identification of fungal metabolites upon the addition of MDBT and its metabolic intermediates. S-oxidation to form MDBT-5-oxide was the initial step of MDBT metabolism. Then, the metabolic pathway was branched to form MDBT-5-dioxide, which was a dead-end product, and hydroxymethylDBT (HMDBT)-5-oxide. Extracellular ligninolytic enzymes such as lignin and manganese peroxidases and laccase did not catalyze the oxidation of either MDBT or MDBT-5-oxide. HMDBT-5-oxide was then oxidized to HMDBT-5-dioxide. Piperonyl butoxide, an inhibitor of cytochrome P450, suppressed fungal oxidation of MDBT to its oxide, MDBT-5-oxide to dioxide and to HMDBT-5-oxide, and HMDBT-5-oxide to dioxide. The efficiency of the inhibition varied for each substrate, suggesting that each oxidation was catalyzed by different enzymes. The hydroxylation of methyl substituents to the hydroxymethyl group was suggested to be catalyzed by a novel monooxygenase. HMDBT-5-dioxide was finally xylosylated most likely by xylosyltrasferase to yield 10-(beta-D-xylopyranosyloxy)-4-methyldibenzothiophene-5-dioxide. The final xyloside product and metabolic intermediates are water-extractable compounds, which would give us a novel strategy for biodesulfurization technology.
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PMID:Bioconversion of recalcitrant 4-methyldibenzothiophene to water-extractable products using lignin-degrading basidiomycete coriolus versicolor 1044 62

Under ligninolytic conditions, the white-rot basidiomycete Coriolus versicolor metabolized chloronitrofen (2, 4, 6-trichloro-4'-nitrodiphenyl ether; CNP) and nitrofen (2, 4-dichloro-4'-nitrodiphenyl ether, NIP), which constitute the largest class of commercially produced diphenyl ether herbicides. The pathway of CNP degradation was elucidated by the identification of fungal metabolites upon addition of CNP and its metabolic intermediates. The metabolic pathway was initially branched to form four metabolites--2, 4, 6-trichloro-3-hydroxy-4'-nitrodiphenyl ether, 2, 4-dichloro-6-hydroxy-4'-nitrodiphenyl ether, NIP, and 2, 4, 6-trichloro-4'-aminodiphenyl ether--indicating the involvement of hydroxylation, oxidative dechlorination, reductive dechlorination, and nitro-reduction. Of these reactions, hydroxylation was relatively major compared to the others. Extracellular ligninolytic enzymes such as lignin peroxidase, manganese peroxidase and laccase did not catalyze the oxidation of either CNP or NIP. Piperonyl butoxide, an inhibitor of cytochrome P450, suppressed fungal oxidation of CNP and NIP to their hydroxylated products. The inhibition resulted in increasing the amount of reductively dechlorinated and nitro-reduced products. These observations strongly suggest that basidiomycetes may possess a mechanism for a strict substrate recognition system and a corresponding metabolic response system to effectively degrade environmentally persistent aromatic compounds.
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PMID:Degradation of diphenyl ether herbicides by the lignin-degrading basidiomycete Coriolus versicolor. 1176 5