Lignin and Mn peroxidase-catalyzed oxidation of phenolic lignin oligomers

Lucia Banci, Simone Ciofi-Baffoni, Ming Tien

Research output: Contribution to journalArticle

74 Scopus citations

Abstract

The oxidation of phenolic oligomers by lignin and manganese peroxidases was studied by transient-state kinetic methods. The reactivity of peroxidase intermediates compound I and compound II was studied with the phenol guaiacol along with a β-O-4 phenolic dimer, trimer, and tetramer. Compound I of both peroxidases is much more reactive than compound II. The rate constants for these substrates with Mn peroxidase compound I range from 1.0 x 105 M-1 s-1 for guaiacol to 1.1 x 103 M-1 s-1 for the tetramer. Reactivity is much higher with lignin peroxidase compound I with rate constants ranging from 1.2 x 106 M-1s-1 for guaiacol to 3.6 x 105 M-1 s-1 for the tetramer. Rate constants with compound II are much lower with Mn peroxidase exhibiting very little reactivity. The rate constants dramatically decreased with both peroxidases as the size of the substrate increased. The extent of the decrease was much more dramatic with Mn peroxidase, leading us to conclude that, despite its ability to oxidize phenols, Mn2+ is the only physiologically significant substrate. The rate decrease associated with increasing substrate size was more gradual with lignin peroxidase. These data indicate that whereas Mn peroxidase cannot efficiently directly oxidize the lignin polymer, lignin peroxidase is well suited for direct oxidation of polymeric lignin.

Original languageEnglish (US)
Pages (from-to)3205-3210
Number of pages6
JournalBiochemistry
Volume38
Issue number10
DOIs
StatePublished - Mar 9 1999

All Science Journal Classification (ASJC) codes

  • Biochemistry

Fingerprint Dive into the research topics of 'Lignin and Mn peroxidase-catalyzed oxidation of phenolic lignin oligomers'. Together they form a unique fingerprint.

  • Cite this