Characterization of celery leaves peroxidase

Abstract

Abstrct:

This research was conducted in food sciences laboratories, college of agricultural and forestry university of  mosul and end in 2017 was aimed to isolate and characterization peroxidase enzyme from celery leaves by water extraction followed by precipitation using different concentrations of acetone ( 1:1 , 1.5:1 , 2:1 acetone : filtrate ). The best ratio was found to be 1.5:1 which gave 74,3%.

Some of the enzyme properties were studied. Optimum temperature for enzyme activity was 40C. The enzyme was found to be relatively thermostable. It  retained all initial activity after 60 minutes of incubation at 50C and 77% at 60C . However, the enzyme had lost all activity upon incubation at 80C for 60 minutes. Optimum pH of activity was 6.3 . Optimal stability was found at pH 5.5 using citrate buffer. Activation energy for the enzyme activity was 3,261k cal.mol^-1, and for enzyme denaturation was 6,131k cal.mol^-1. Michaelis constant (Km) and maximum velocity (Vmax) were calculated to be 20 mM and 2 µmol. Min^-1, respectively using guaiacol as substrate.