EXTRACTION, PURIFICATION AND CHARACTERIZATION OF CYTOSINE DEAMINASE FROM Saccharomyces cerevisiae

Abstract

The cytosine deaminase was extracted by using organic solvent toluene and the value of specific activity of crude extract was (9.6) mu/mg protein . The enzyme was purified in few steps including precipitating the enzyme by using ammonium sulfate at defferent saturation percent, The optimum percent was 60% saturation percent which gave value of specfic activity of (12.5) mu/mg protein fold of purification was (1.302) times and the yield was 4.82% . Then the enzume solution was passed through DEAE – cellulose column chromatography. The peaks was collected and the value of specific activity was measured which was (358) mu/mg protein, fold of purification was (37.29) times, and the yield was (2.55)%.
The enzyme solution was concentrated and passed through sephadex G-200 gelfilteration and the value of specific activity was (400) mu/mg protein, fold purification (41.66) times and yeid was 1.19%.