GLUL also known as Glutamine synthetase. It is a trimetallic enzyme containing two divalent cation sites and one monovalent cation site per subunit. GLUL is able to regulate intracellular concentrations of glutamate and catalyzes the synthesis of glutamine form glutamate and ammonia. It is ubiquitously expressed in the human and plays a major role for many metabolic pathways such as cell proliferation, inhibition of apoptosis, and cell signaling. Recombinant Human GLUL was expressed in E.coli and purified by using conventional chromatography techniques