Cloning and Expression of a Gene Encoding a Secondary Aldehyde Dehydrogenase in Thermoanal Aerobacter Ethanolicus 39E and Biochemical Characterization of the Enzyme

摘要

The adhB gene encoding the secondary alcohol dehydrogenase (2-Adh) of thermoanal aerobacter ethanololix 39E was cloned, sequenced and expressed in Escherichia coli. Nucleic acid sequences and amino acid sequences encoding this enzyme have been reported in the present application. The purified recombinant enzyme is a homodimer consisting of subunits of 37.7 kDa and has a half-life of about 1.7 hours at 90C and optimum activity at 90C or higher. This enzyme takes precedence over the oxidation of secondary alcohols rather than primary alcohols.