Cloning and Expression of Different Genotypes of Human Aldehyde Dehydrogenase 2 Gene

Aldehyde dehydrogenase 2 (ALDH2) plays an important role in the cellular defense against toxic aldehydes for its ability to catalyze the oxidation of various aliphatic and aromatic aldehyde to the corresponding acids. It was reported that a high-frequency of mutant aldh2 allele (aldh2*2) existed in Asian population and the inherited deficiency of aldh2 may be the cause of the flushing syndrome and the uncomfortable effects of drinking alcohol. In this experiment, we successfully expressed ALDH2 and ALDH2*2, and identified the enzymatic activity of the two products for acetaldehyde. Their K_ms were 1.70μmol/L and 61.56 μmol/L respectively. This result supports the previous conclusion that the inherited deficiency of aldh2 is associated with the flushing syndrome and uncomfortable effects of drinking alcohol.