Alanine Racemase from Bacillus stearothermophilus

Alanine racemase is used to convert L-alanine into D-alanine. Alanine racemase, from Sigma, has been used to isomerize L-[U-¹⁴C]alanine to a racemic mixture of L/D- [¹⁴C]alanine †.

Alanine racemase is involved in alanine, aspartate and D-alanine metabolism. 3-Fluoro-D-alanine and D-Cycloserine are known to inhibit alanine racemase.† Alanine racemase monomer is composed of two domains, an eight-stranded α/β barrel at the N-terminus and a C-terminal domain. The N-terminus includes residues 1-240, whereas the C-terminal comprises of the β-strand (residues 241-388). One molecule of pyridoxalphosphate (PLP) is present as the cofactor in each subunit.†

One unit will convert 1.0 μmole of D-alanine to L-alanine per minute at pH 10.5 at 30 °C in a coupled assay system with L-alanine dehydrogenase.

Aqueous solution containing 10 mM potassium phosphate