title: Tuning of the product spectrum of vanillyl-alcohol oxidase by medium engineering.
abstract: The flavoenzyme vanillyl-alcohol oxidase (VAO) catalyzes the conversion of 4-alkylphenols through the initial formation of p-quinone methide intermediates. These electrophilic species are stereospecifically attacked by water to yield (R)-1-(4'-hydroxyphenyl)alcohols or rearranged in a competing reaction to 1-(4'-hydroxyphenyl)alkenes. Here, we show that the product spectrum of VAO can be controlled by medium engineering. When the enzymatic conversion of 4-propylphenol was performed in organic solvent, the concentration of the alcohol decreased and the concentration of the cis-alkene, but not the trans-alkene, increased. This change in selectivity occurred in both toluene and acetonitrile and was dependent on the water activity of the reaction medium. A similar shift in alcohol/cis-alkene product ratio was observed when the VAO-mediated conversion of 4-propylphenol was performed in the presence of monovalent anions that bind specifically near the enzyme active site.
authors.affiliation: Department of Agrotechnology and Food Sciences, Wageningen University, The Netherlands.
authors.forename: R H
authors.initials: RH
authors.lastname: van den Heuvel
authors.forename: J
authors.initials: J
authors.lastname: Partridge
authors.forename: C
authors.initials: C
authors.lastname: Laane
authors.forename: P J
authors.initials: PJ
authors.lastname: Halling
authors.forename: W J
authors.initials: WJ
authors.lastname: van Berkel
mesh_terms: D000097:Acetonitriles; D000429:Alcohol Oxidoreductases / Q000737:chemistry / Q000378:metabolism*; D000438:Alcohols / Q000737:chemistry / Q000378:metabolism; D000475:Alkenes / Q000737:chemistry / Q000378:metabolism; D002384:Catalysis; D020134:Catalytic Domain; D004738:Engineering; D008958:Models, Molecular; D010407:Penicillium / Q000201:enzymology; D012997:Solvents; D013237:Stereoisomerism; D014050:Toluene; D014867:Water
chemical_list: D000097:Acetonitriles; D000438:Alcohols; D000475:Alkenes; D012997:Solvents; D014867:Water; D014050:Toluene; D000429:Alcohol Oxidoreductases; C076865:vanillyl-alcohol oxidase; C032159:acetonitrile