Allylic or Benzylic Stabilization Is Essential for Catalysis by Bacterial Benzyl Alcohol Dehydrogenases

• Published in: Biochemical and biophysical research communications Vol. 259; no. 1; pp. 220 - 223
• Main Authors: Curtis, Abigale J., Shirk, Megan C., Fall, Ray
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 27-05-1999
• Subjects: Acinetobacter calcoaceticus; Acinetobacter calcoaceticus - enzymology; Alcohol Oxidoreductases - genetics; Alcohol Oxidoreductases - metabolism; Benzyl Alcohol - metabolism; Benzyl alcohol dehydrogenase; Catalysis; Escherichia coli; Kinetics; Molecular Structure; Oxidation-Reduction; Propanols - metabolism; Pseudomonas putida; Pseudomonas putida - enzymology; Recombinant Proteins - genetics; Recombinant Proteins - metabolism; Substrate Specificity
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1006/bbrc.1999.0738

Benzyl alcohol dehydrogenase fromAcinetobacter calcoaceticus(AC-BADH) and TOL plasmid-encoded benzyl alcohol dehydrogenase fromPseudomonas putida(TOL-BADH) have previously been shown to oxidize a variety of aromatic alcohols but not aliphatic substrates. Here, we have expressed the genes for AC-BADH and TOL-BADH inEscherichia coli,purified the resulting over-expressed enzymes, and shown that each is an effective catalyst of both benzylic and allylic alcohol oxidation, but not of oxidation of nonallylic analogs. Enzyme specificity (kcat/Km) for both enzymes was higher with an aliphatic, allylic alcohol (3-methyl-2-buten-1-ol) than with benzyl alcohol. These results suggest that bacterial benzyl alcohol dehydrogenases use the resonance stabilization provided by allylic and benzylic alcohols to promote catalysis.