Purification and Characterization of the First Archaeal Glutamate Decarboxylase fromPyrococcus horikoshii

Glutamate decarboxylase (GAD) from the archaeon Pyrococcus horikoshii was successfully expressed and purified, with the aim of developing a hyperthermostable GAD for industrial applications. Its biochemical properties were different from those reported for other GADs. The enzyme had broad substrate specificity, and its optimum pH and temperature were pH 8.0 and >97 °C.