Purification and characterization of a veratryl alcohol oxidase enzyme from the lignin degrading basidiomycete Pleurotus ostreatus

A veratryl alcohol oxidase (VAO) enzyme was discovered in cultures of Pleurotus ostreatus. The enzyme, which oxidizes veratryl alcohol to veratraldehyde reducing O2 to H202, was purified to homogeneity and its main structural and catalytic properties have been determined. The enzyme is a glycoprolein and contains FAD as a prosthetic group. The amino acid composition and carboxy- and amino-terminal sequences were determined. Primary aromatic alcohols with methoxy substituents in position four are good substrates for VAO; cinnamyl alcohol is the substrate which is oxidized faster whereas coniferyl alcohol is oxidized at a slower rate. The enzyme is moderately thermostable [t1/2 (55 °C) about 1.5 h, apparent melting temperature about 60 ° C]. The enzyme stability in 50% water/organic solvents mixtures has also been studied.