Purification and characterization of glutaminase from Iraqi fruit of ‎ Capsicum annuum

Abstract

L-glutaminase has recently attracted much attention due to its medicinal and industrial potential. It's an antileukemic drug with flavor-enhancing properties when used in fermented foods manufacturing. The enzyme purification was determined by ammonium sulfate precipitation, Ion exchange chromatography and gel filtration chromatography with estimating glutaminase activity and characterization of purified glutaminase in several parameters such as substrate concentration and reaction time pH, and temperature influence in this study. As a result, glutaminase is purified in three steps: ammonium sulfate precipitation with 30% saturation, DEAE-Cellulose and Sephacryl S-200. The specific activity increased to 85 U/mg protein with 4 folds of purification and 18% enzyme recovery. When glutaminase was incubated in the presence of 150 millimolar glutamine at thirty-five centigrade for thirty minutes, the enzyme reached its maximal activity of 1.8 u/ml, in the presence of a 0.05 Molar potassium phosphate buffer solution, at pH 8. Keywords: Capsicum annum, glutaminase, enzyme activity, glutaminase purification