L-Alanine Dehydrogenase from Bacillus subtilis

L-Alanine dehydrogenase converts L-alanine to pyruvate and ammonium. L-Alanine dehydrogenase from Bacillus subtilis may be used to study enzyme inactivation and protection .

L-Alanine dehydrogenase is an A-stereospecific dehydrogenase that catalyzes the reversible deamination of L-alanine to pyruvate and ammonium. It is important for the generation of pyruvate during sporulation. L-Alanine dehydrogenase from Bacillus subtilis has a predominately ordered kinetic mechanism in which NAD binds before L-alanine. Subsequently, ammonia, pyruvate, and NADH are released in that specific order. Optimal pH for the amination reaction is 8.8-9.0, whereas it is 10-10.5 for the deamination reaction. The enzyme is inactivated by divalent metal ions and p-chloromercuribenzoate, mercuric ion being most effective. The inactivation may be reversed by L- or D-cysteine.

One unit will convert 1.0 μmole of L-alanine to pyruvate and NH₃ per min at pH 10.0 at 25 °C.

Solution in 50% glycerol containing 10 mM potassium phosphate buffer, pH 7.7