Aryl-alcohol oxidase involved in lignin degradation: a mechanistic study based on steady and pre-steady state kinetics and primary and solvent isotope effects with two alcohol substrates.

ABSTRACT: Aryl-alcohol oxidase (AAO) is a FAD-containing enzyme in the GMC (glucose-methanol-choline oxidase) family of oxidoreductases. AAO participates in fungal degradation of lignin, a process of high ecological and biotechnological relevance, by providing the hydrogen peroxide required by ligninolytic peroxidases. In the Pleurotus species, this peroxide is generated in the redox cycling of p-anisaldehyde, an extracellular fungal metabolite. In addition to p-anisyl alcohol, the enzyme also oxidizes other polyunsaturated primary alcohols. Its reaction mechanism was investigated here using p-anisyl alcohol and 2,4-hexadien-1-ol as two AAO model substrates. Steady state kinetic parameters and enzyme-monitored turnover were consistent with a sequential mechanism in which O(2) reacts with reduced AAO

SUBMITTER: Ferreira P 

PROVIDER: S-EPMC2757187 | biostudies-literature | 2009 Sep

REPOSITORIES: biostudies-literature