Phosphate activated glutaminase-like immunoreactivity in the nervous system from different species and in different neuronal cell types and in astrocytes

Using antibodies against pig brain phosphate activated glutaminase, the enzyme appears to be rather conservative as we have observed immuno- staining in the brain from all species investegated pig, cow, rabbit, rat, mouse, man, fish (cod and salmon) and bird (chicken)]. In addition, phosphate activated glutaminase from cultured mouse cerebral cortex inter- neurons (mainly GABA-ergic), cerebellar granule cells (glutamatergic) and astrocytes stained in an analogous manner. However, no phosphate activated glutaminase-like immunostaining was found in lobster ganglion. yeast and E. coli. Using the Western blotting technique, phosphate activated glutaminase from dodecyl sulfate treated samples from all the above mentioned preparations revealed a MW close to 64 K_d. The MW is similar to the MW of the subunit of phosphate activated glutaminase in a highly purified pig brain preparation, The Western blotting technique seems to be well suited to identify phosphate activated glutaminase-like immunoreactivity in different tissues.