عزل و تنقية جزئية لأنزيم الكلوتامين سنثتيز من كالس نبات الحبة السوداء (Nigella sativa L.)‎

Abstract EN

Callus induction occurred on stem segments of Nigella sativa L.

seedlings grown on a modified Murashige and Skoog medium containing 10-6 M of 2, 4- dichlorophenoxy acetic acid (2, 4 – D).

Glutamine synthetase (EC 6.

3 .

1.

2) was isolated and partially purified from Nigella sativa L.

callus the partially purified enzyme from the aqueous extract by ammonium sulfate precipitation, dialysis and gel filtration on sephadex G – 200 revealed that the activity increased by 37 fold.

The molecular weight by gel – filtration chromatography was found to be around 50000 Da.

The optimum conditions of the partially purified glutamine synthetase from callus were obtained by using Tris – HCl (80 mM) at pH 2.7 as a buffer and 10 mM of glutamate as substrate with incubation temperature 30° C.

The Michaelis Menten constants for glutamate, adenosinetriphophate and ammonium chloride were 10 × 10-3M, 2 × 10-3 M and 0.280 × 10-3 M respectively.