Jo JE, Mohan Raj S, Rathnasingh C, Selvakumar E, Jung WC, Park S. Cloning, expression, and characterization of an aldehyde dehydrogenase from Escherichia coli K-12 that utilizes 3-Hydroxypropionaldehyde as a substrate.
Appl Microbiol Biotechnol 2008;
81:51-60. [PMID:
18668238 DOI:
10.1007/s00253-008-1608-x]
[Citation(s) in RCA: 88] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2008] [Revised: 07/06/2008] [Accepted: 07/07/2008] [Indexed: 10/21/2022]
Abstract
3-Hydroxypropionaldehyde (3-HPA), an intermediary compound of glycerol metabolism in bacteria, serves as a precursor to 3-Hydroxypropionic acid (3-HP), a commercially valuable platform chemical. To achieve the effective conversion of 3-HPA to 3-HP, an aldH gene encoding an aldehyde dehydrogenase in Escherichia coli K-12 (AldH) was cloned, expressed, and characterized for its properties. The recombinant AldH exhibited broad substrate specificity for various aliphatic and aromatic aldehydes. AldH preferred NAD+ over NADP+ as a cofactor for the oxidation of most aliphatic aldehydes tested. Among the aldehydes used, the specific activity was highest (38.1 U mg(-1) protein) for 3-HPA at pH 8.0 and 37 degrees C. The catalytic efficiency (kcat) and the specificity constant (kcat/Km) for 3-HPA in the presence of NAD+ were 28.5 s(-1) and 58.6x10(3) M(-1) s(-1), respectively. The AldH activity was enhanced in the presence of disulfide reductants such as dithiothreitol (DTT) or 2-mercaptoethanol, while several metal ions, particularly Hg2+, Ag+, Cu2+, and Zn2+, inhibited AldH activity. This study illustrates that AldH is a potentially useful enzyme in converting 3-HPA to 3-HP.
Collapse