Merck, A6338-25UN, Aldehyde Dehydrogenase, potassium-activated from baker’s yeast (S. cerevisiae)

Aldehyde dehydrogenase is a tetramer and has several different isoforms. The enzyme tested in 0.01 M pyrophosphate buffer shows a sharp optimum around pH 9.3 with acetaldehyde as substrate. Potassium ions and cysteine are essential for the enzyme′s activity. Rubidium or NH4⁺ can be substituted for K⁺, and glutathione for cysteine. Lithium, Na⁺, and Cs⁺ inhibit the reaction. Aldehyde dehydrogenase is inhibited by propylurea, crotonaldehyde, n-propyl isocyanate, cyclohexyl isocyanate, 1-n-propyl-1-[(4-chlorophenyl)sulphonyl]-3-n-propylurea, and 1-methyl-1-[(4-chlorophenyl)sulphonyl]-3-n-propylurea. The enzyme may be utilized to quantitate aldehydes present in blood.