Abstract
Cytosine deaminase was purified about 900-fold from the cell-free extract of Serratia marcescens. The purification procedure included heat treatment, ammonium sulfate fractionation, ethyl alcohol fractionation, DEAF-cellulose and hydroxylapatite column chromatography, and Sephadex G-200 gel filtration.
The enzyme was homogeneous by the criteria of ultracentrifugation and acrylamide gel electrophoresis. The molecular weight was determined to be approximately 580, 000 and the molecule was composed of equimolecular weight of 8 subunits.
The enzyme catalyzed the stoichiometric conversion of cytosine into uracil and ammonia.
