H2O2 generation during the auto‐oxidation of coniferyl alcohol drives the oxidase activity of a highly conserved class III peroxidase involved in lignin biosynthesis

FEBS Letters

Caballero, Nuria¹  Pedreño, Marı́a A¹  Pomar, Federico¹  Ros Barceló, A¹ 

[1] Department of Plant Biology (Plant Physiology), University of Murcia, E-30100 Murcia, Spain

关键词: Auto-oxidation;    Coniferyl alcohol;    H2O2 generation;    Oxidase reaction;    Peroxidase;   

DOI  :  10.1016/S0014-5793(02)03339-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Characterization of lignified Zinnia elegans hypocotyls by both alkaline nitrobenzene oxidation and thioacidolysis reveals that coniferyl alcohol units are mainly found as part of 4-O-linked end groups and aryl-glycerol-β-aryl ether (β-O-4) structures. Z. elegans hypocotyls also contain a basic peroxidase (EC 1.11.1.7) capable of oxidizing coniferyl alcohol in the absence of H₂O₂. Results showed that the oxidase activity of the Z. elegans basic peroxidase is stimulated by superoxide dismutase, and inhibited by catalase and anaerobic conditions. Results also showed that the oxidase activity of this peroxidase is due to an evolutionarily gained optimal adaptation of the enzyme to the μM H₂O₂ concentrations generated during the auto-oxidation of coniferyl alcohol, the stoichiometry of the chemical reaction (mol coniferyl alcohol auto-oxidized/mol H₂O₂ formed) being 0.496. These results therefore suggest that the H₂O₂ generated during the auto-oxidation of coniferyl alcohol is the main factor that drives the unusual oxidase activity of this highly conserved lignin-synthesizing class III peroxidase.

【 授权许可】

Unknown