Purification and Properties of Ornithine Racemase from Clostridium sticklandii

Ornithine racemase has been purified to homogeneity from Clostridium sticklandii, as shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. This is the first racemase known to be highly specific to ornithine. This PLP-dependent enzyme has an Mr of 92,000, with a Km for l-ornithine of 0.77 ± 0.05 mM and a kcat of 980 ± 20 s−1.