Studies on the Guanosine Degrading System in Bacterial Cell

Part III. Purification and Properties of Guanosine Deaminase

Abstract

A highly purified preparation of the enzyme, guanosine deaminase, has been obtained by a four-step purification procedure from the cells of Pseudomonas convexa No. 149. The enzyme deaminates guanosine, deoxyguanosine and 8-azaguanosine, and the deamination of guanosine is inhibited by Hg²⁺ and 4-amino-5-imidazole carboxamide ribonucleoside.
The enzyme has the optimum pH at pH range from 6.0 to 6.5 and the optimum temperature at 45°C. Metal ions are not required for the enzyme activity.
The molecular weight of the enzyme is 1×10⁵ to 2×10⁵.