Lactaldehyde dehydrogenase (EC 1.2.1.22), Escherichia coli

Lactaldehyde dehydrogenase (E.C. 1.2.1.22) from E. coli (aldA gene product, P25553) is a homotetrameric protein, localized in the cytoplasm, which unliganded 3D structure bas been deposited in the RCSB Protein Data Bank with accession code 2hg2 (Constanzo et al., 2007). Each monomer is composed of a catalytic domain, a cofactor NAD+ binding domain and an oligomerization domain. This enzyme, with systematic name L-lactaldehyde:NAD+ oxidoreductase, belongs to the superfamily of NAD+- or NADP+- dependent enzymes that catalyze the oxidation of aldehydes to the corresponding carboxylic acids. These enzymes are widespread in all living systems, from archea to eukaryotes, where they metabolize endogenous and exogenous aldehydes. This lactaldehyde dehydrogenase from E. coli is an NAD+-dependent enzyme implicated in the metabolism of L-fucose and L-rhamnose (Baldoma and Aguillar, 1987). L-lactaldehyde is generated as an intermediate in the metabolism of L-fucose and L-rhamnose in bacteria that utilize these carbohydrates as a carbon source. However, the enzyme may function in multiple metabolic pathways due to its ability to catalyse the oxidation of several aldehydes, with a Km in the micromolar range for alpha-hydroxyaldehydes (lactaldehyde, glyceraldehydes or glycoaldehyde), and a higher Km, in the millimolar range, for the alpha- ketoaldehyde methylglyoxal. The enzyme is provided in 3.2 M ammonium sulphate. Temperature and pH optimum/stability: The optimum pH and temperature are 9.5 and 25 °C, respectively. Shipping Conditions: Room Temperature. Storage Conditions: 2 °C to 8 °C. Features: >95% pure (SDS-PAGE). aldA, b1415, Aldehyde dehydrogenase A, Lactaldehyde dehydrogenase, Glycolaldehyde dehydrogenase