Characterization of a putative tropinone reductase from Tarenaya hassleriana with a broad substrate specificity

Abstract

A novel short‐chain alcohol dehydrogenase from Tarenaya hassleriana labeled as putative tropinone reductase was heterologously expressed in Escherichia coli. Purified recombinant protein had molecular weight of approximately 30 kDa on 12% sodium dodecyl sulfate‐polyacrylamide gel electrophoresis. T. hassleriana tropinone reductase‐like enzyme (ThTRL) had not detected oxidative activity. The optimum pH for enzyme activity of ThTRL was weakly acidic (pH 5.0). 50°C was the optimum temperature for ThTRL. The highest catalytic efficiency and substrate affinity for recombinant ThTRL were observed with (+)‐camphorquinone (kcat/Km = 814.3 s–1 mM–1, Km = 44.25 μM). ThTRL exhibited a broad substrate specificity and reduced various carbonyl compounds, including small lipophilic aldehydes and ketones, terpene ketones, and their structural analogs.