Purification and characterisation of NAD-glutamate dehydrogenase from Aspergillus nidulans

NAD-Glutamate dehydrogenase has been purified from mycelia of A. nidulans. The enzyme comprises subunits of 110 kDa. It is located in the cytosol. It is completely denatured by 1.0 M guanidine hydrochloride, and is not renatured by subsequent dilution. Isophthalate is a strong competitive inhibitor and the enzyme is also inhibited by thiol reagents. The properties of the enzyme were compared to those from other fungi in terms of size, sensitivity to inhibitors, intracellular distribution and mode of regulation, and were found to resemble most closely those of Neurospora crassa.