Purification and Characterization of Formaldehyde Dehydrogenase in a Methanol-utilizing Yeast, Kloeckera sp. No. 2201

Abstract

An NAD-linked formaldehyde dehydrogenating enzyme was found in the cell-extract of Kloeckera sp. No. 2201, which utilized methanol as a sole source of carbon. The enzyme was inducibly formed in methanol-grown cells. This fact suggests that the enzyme may play a significant role in the methanol metabolism of this yeast. The enzyme was purified from a cell-extract by ammonium sulfate fractionation, column chromatographies on DEAE-cellulose and on hydroxylapatite, and Sephadex G-200 gel filtration. From an experiment with the purified enzyme, it was found that the enzyme specifically required reduced glutathione for activity, and was reactive toward methylglyoxal as well as formaldehyde. The enzyme catalyzed the following reaction: Formaldehyde+NAD+H₂O→formic acid+NADH+H_??_ the enzyme was concluded to be a kind of formaldehyde dehydrogenase (formaldehyde: NAD oxidoreductase, EC 1. 2. 1. 1). Other properties of the enzyme were also investigated.