Characterization of glutamine synthetase isoforms from chlorella.

A Thioredoxin Activated Glutamine Synthetase in Chlorella

Glutam ine synthetase was partly purified from Chlorella pyrenoidosa. This enzyme activity was stimulated by dithioerythritol and 2'-3'-dimercaptopropanol (BAL). Full activation was obtained by thioredoxins isolated from the cyanobacterium Synechococcus 6301, from spinach and by heated Chlorella extract. The apparent Km for the purified thioredoxin B from Synechococcus 6301 was determined to be...

Glutamine Synthetase in Rice: A COMPARATIVE STUDY OF THE ENZYMES FROM ROOTS AND LEAVES.

Chromatographic, kinetic, and regulatory properties of glutamine synthetase in rice were investigated. By DEAE-Sephacel column chromatography, two forms (glutamine synthetase 1 and glutamine synthetase 2) were identified in leaves and one form (glutamine synthetase R) was identified in roots. Purification on hydroxyapatite and gel electrophoresis showed that glutamine synthetase R was distinct ...

The structures of cytosolic and plastid-located glutamine synthetases from Medicago truncatula reveal a common and dynamic architecture

The first step of nitrogen assimilation in higher plants, the energy-driven incorporation of ammonia into glutamate, is catalyzed by glutamine synthetase. This central process yields the readily metabolizable glutamine, which in turn is at the basis of all subsequent biosynthesis of nitrogenous compounds. The essential role performed by glutamine synthetase makes it a prime target for herbicida...

Biochemical and molecular analysis of glutamine synthetase gene in brassica napus L.

Glutamine Synthetases of Higher Plants : Evidence for a Specific Isoform Content Related to Their Possible Physiological Role and Their Compartmentation within the Leaf.

The chromatographic properties of glutamine synthetase isoforms have been investigated in a wide range of higher plant leaves and shoots using ion exchange chromatography. Different patterns of glutamine synthetase isoform content were observed. Among higher plants, four patterns or groups could be recognized. The first group is characterized by having only cytosolic glutamine synthetase, where...