A study of the activity and properties of the enzyme cytidine deaminase partially purified from the tissues of the earthworm (Lumbricus terrestris (Linnaeus), 1758).

Abstract

The present research includes a study of the activity and properties of enzyme
cytidine deaminase (EC. 3.5.4.5) in the extract of earthworm Lumbricus terrestris.
Maximum activity of the enzyme was obtained in a reaction mixture
containing (300) μM of Tris-HCl buffer at pH (7.2) containing (8) μM cytidine as a
substrate and a concentration of enzyme extract equal to (60) μg. The reaction mixture
was incubated at (37)◦C for (15)min. Under the optimum conditions, the specific
activity was found to be (31.76 ± 1.1) μM of uridine per min. per mg protein in the
supernatant of L. terrestries extracts compared with (20.24 ± 0.31) μM of uridine per
min. per mg protein. The Michaelis constant (Km) value was (1.81 × 10-3 M).
The research also included an isolation and partial purification of CDA by gel
filration chromatography using sephadex G-200, the number of purification folds for
the CDA was (6), and the molecular weight was found to be a round (95000) D.