Ligninase-mediated phenoxy radical formation and polymerization unaffected by cellobiose:quinone oxidoreductase. Biochimie 1988 Jun;70(6):847-52
Date
06/01/1988Pubmed ID
2844307DOI
10.1016/0300-9084(88)90117-4Scopus ID
2-s2.0-0023729086 (requires institutional sign-in at Scopus site) 51 CitationsAbstract
Phanerochete chrysosporium ligninase (+ H2O2) oxidized the lignin substructure-related compound acetosyringone to a phenoxy radical which was identified by ESR spectroscopy. Cellobiose:quinone oxidoreductase (CBQase) + cellobiose, previously suggested to be a phenoxy radical reducing system, was without effect on the radical. Ligninase polymerized guaiacol and it increased the molecular size of a synthetic lignin. These polymerizations, reflecting phenoxy radical coupling reactions, were also unaffected by the CBQase system. We conclude that ligninase catalyzes phenol polymerization via phenoxy radicals, which CBQase does not affect. The CBQase system also did not produce H2O2, and its physiological role remains obscure. Glucose oxidase + glucose did produce H2O2 as expected, but, like CBQase, it did not reduce the phenoxy radical of acetosyringone. Because intact cultures of P. chrysosporium depolymerize lignins, it is likely that phenol polymerization by ligninase is prevented or reversed in vivo by an as yet undescribed system.
Author List
Odier E, Mozuch MD, Kalyanaraman B, Kirk TKAuthor
Balaraman Kalyanaraman PhD Professor in the Biophysics department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
BasidiomycotaCarbohydrate Dehydrogenases
Chromatography, Gel
Electron Spin Resonance Spectroscopy
Free Radicals
Guaiacol
Lignin
Oxidation-Reduction
Oxygenases
Polymers
