Stability, activity and substrate specificity of alcohol dehydrogenases in media containing organic solvents

Abstract

The stability, activity and substrate specificity of two alcohol dehydrogenases, membrane bound (mADH) from Gluconobacter sp. 33 and soluble (ADH IIG) from Pseudomonas putida HK5, in media containing organic solvents were investigated. ADH IIG was more stable in organic solvents than mADH. Organic solvents in the reaction mixture decreased the rate of substrate oxidation and increased the Km. The substrate specificity of ADH IIG and mADH was different for water-insoluble substrates. ADH IIG used cyclo-, primary and secondary alcohols with long carbon chain as substrates, but mADH used effectively only 1-octanol when organic solvents were present in the reaction mixture. Keywords: alcohol dehydrogenase, pyrroloquinoline quinone (PQQ),organic solvents, enzyme inhibition, log P