Oxidation of aromatic alcohols by purified methanol dehydrogenase from Methylosinus trichosporium

Abstract

Methanol dehydrogenase was found to be present in subcellular preparations of methanol-grown Methylosinus trichosporium and occurred almost wholly in the soluble fraction of the cell. The enzyme, purified by DEAE-Sephadex and Sephadex G-100 chromatography, showed broad specificity toward different substrates and oxidized the aromatic alcohols benzyl, vanillyl, and veratryl alcohols in addition to a range of aliphatic primary alcohols. No enzyme activity was found toward the corresponding aldehydes of the alcohols tested. The Km for methanol was 50 microM, and that for the aromatic alcohols was in the range of 1 to 2 mM. EDTA and p-nitrophenylhydrazine, which are inhibitors of methanol oxidation in whole cells of methylotrophs, had little effect on activity of the purified enzyme. The results now extend the range of substrates oxidized by methanol dehydrogenase to include the aromatic alcohols.