Summary: Glutamine synthetase (EC was purified about 430-fold from the nitrifying bacterium by affinity chromatography on Blue Sepharose CL-6B and gel filtration on Sepharose 4B. The enzyme (apparent mol. wt 700000), which consisted of 12 subunits, each of mol. wt 58000, required a divalent cation for both biosynthetic and transferase activities. Regulation of glutamine synthetase both by a feedback inhibition involving amino acids and by an adenylylation/deadenylylation mechanism was studied. The enzyme was highly adenylylated (75-90%) in cell free extracts from cells grown on nitrite as the sole source of nitrogen. The adenylylated form of the enzyme could be deadenylylated by treatment with snake venom phos-phodiesterase. An isoactivity pH of 7·4 was recorded for glutamine synthetase.


Article metrics loading...

Loading full text...

Full text loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error