Aldehyde Dehydrogenase, potassium-activated from baker′s yeast (S. cerevisiae)

Aldehyde dehydrogenase (ALDH) has been used to evaluate the effects of pear extracts on ALDH activity. It has also been used to colorimetrically determine ethanol by monitoring the enzymatic reduction of nicotinamide adenine dinucleotide (NAD).

Aldehyde dehydrogenase from baker′s yeast catalyzes the reduction of pyridine nucleotides by several aldehydes. It catalyzes the oxidation of a wide range of substrates, such as acetaldehyde, formaldehyde, propionaldehyde, n-butylaldehyde, isobutylaldehyde, n-valeraldehyde, caproaldehyde, benzaldehyde, glycoaldehyde, D-glyceraldehyde, malonic semialdehyde, and succinic aldehyde. Aldehyde dehydrogenase is used to study the production of ethanol and isobutanol. Ethanol concentration can be determined colorimentrically by monitoring the enzymatic reduction of nicotinamide adenine dinucleotide (NAD) using alcohol dehydrogenase after preremoval of aldehyde by aldehyde dehydrogenase.

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.

Aldehyde dehydrogenase (ALDH) is present in the nucleus, cytosol, mitochondria and endoplasmic reticulum of cells.

One unit will oxidize 1.0 μmole of acetaldehyde to acetic acid per min at 25 °C at pH 8.0 in the presence of β-NAD⁺, potassium and thiols.

Contains lactose, potassium phosphate and citrate buffer salts, and mercaptosuccinic acid.

This enzyme can be dissolved at 0.3 mg/mL in 100 mM Tris-HCl buffer (pH 8.0), containing 0.02% BSA.