Purification and characterisation of an NAD⁺-dependent secondary alcohol dehydrogenase from Pseudomonas maltophilia MB11L

A constitutive NAD+-linked alcohol dehydrogenase was purified 338-fold from cells of Pseudomonas maltophilia MB11L grown on glucose. Maximum activity was observed with cyclic and linear secondary alcohols, with little activity seen against primary or aromatic alcohols. Substrate oxidation activity was maximal at pH 10.0, while substrate reduction was optimal at pH 4.5. The Km values for propan-2-ol, NAD+ and acetone were 87, 413 and 143 μM respectively. The enzyme is a tetramer with subunit Mr of approximately 44 000. It has an isoelectric point of 4.75, and was inhibited by chelating agents, thiol reagents and certain metal ions. © 1992.