Crystallization of an NAD+-dependent glutamate dehydrogenase from Clostridium symbiosum

Crystals of a bacterial NAD+-dependent glutamate dehydrogenase (GDHase) have been grown over a wide range of pH values by using the hanging drop method of vapour diffusion with ammonium sulphate as the precipitant. Sodium dodecyl sulphate/polyacrylamide gel electrophoresis of this enzyme together with high pressure liquid chromatography/gel filtration, shows that this GDHase is hexameric like the GDHases of vertebrates. X-ray photographs of the crystals show that they diffract to at least 2.0 A, and an analysis of the diffraction pattern demonstrates that the hexamer is arranged in at least pseudo 32 symmetry.