Kinetic and inhibition studies for glutathione peroxidase(GPx)‎ isolated from pea (Pisum sativum)‎ locality

الملخص EN

This research is included the isolation of glutathione peroxidase (GPx) from the pea (Pisum sativum), studied the factors effecting the activity of the enzyme and determination of its molecular weight.

One proteinous band had been isolated by gel filtration sephadex (G-50) from the proteinous supernatant produced by ammonium sulfate saturation (65 %) after dialysis and the product from (G-50) give two bands by sephadex (G-100).

It was found that the first peak (Peak A) had a high activity for (GPx).

The apparent molecular weight of the isolated enzymes using gel filtration chromatography was (89388 + 850) Dalton for GPx.

The results also showed that the optimum conditions of GPx was obtained at (100μg / ml) of enzyme concentration using (25 mmol / l) of glutathione (GSH) as a substrate, phosphate buffer (0.5 mol / l) as a buffer at pH (7.5) for (12) minutes at (40C).

Using Lineweaver–Burk plot, the values of maximum velocity (Vmax) and Michaelis constant (Km) were (2.1 μmol / min) and (1.25 mmol / l) respectively.

Beside of, the study showed inhibition for antibiotics, analgesic and other types drugs on the enzyme activity, especially of psedeuphidrine and flagyl.