Extraction and characterization of Arylesterase enzyme from (peel and pulp) of Annona muricata fruit.

Abstract

The extraction of arylesterase from the aqueous extract of (peel and pulp) of Annona muricata fruit was conducted using different biochemical techniques. It was shown that, max activity was obtained in the pulp than in peel, and by using gel filtration chromatography on sephadex G-75 for the pulp part, the solution of the proteinous precipitate produced by acetone precipitation, contained three proteinous peaks. The activity for peak A (1653) and peak B(2310.9) but the third peak C was very low. while maximum specific activity was obtained in the second peak (B) which showed (23107), (18366 ) IU/ml /mg for (A) and very low for the third one (C), and (12.58),(26.531) folds of purification for B and A peaks respectively .Furthermore, the comparative molecular weight of the partially purified isoenzymes arylesterase (peaks B and A) using gel filtration were found to be (92,129), (86,895) Dalton respectively. The optimum conditions of arylesterase were determined as maximum activity was obtained using (9 mM) Tris – HCl as a buffer at pH (7.2), with incubation temperature (37ºC), incubation time (25min) and (4mM) of phenyl acetate as a substrate. Using Linweaver–Burk plot, it was found that maximum velocity (Vmax) and Michaela’s constant (Km) had the values of (211UI/ml) and (2.8 mM) respectively.

Keywords

• arylesterase
• annona muricata
• gel filtrations
• optimum conditions