Regulatory Mechanisms in the Human Leukocyte : I. The Feedback Control of Deoxycytidylate Deaminase

The feedback control of dCMP deaminase, the first enzyme in a biosynthetic sequence of pyrimidine deoxyribonucleotide interconversions, has been characterized in leukocytes isolated from the peripheral blood of normal subjects and from patients with leukemia. As reported in other systems, dTTP, an end product of the pathway, may function as an allosteric inhibitor of this enzyme, while dCTP, another end product, prevents the dTTP inhibition.

Nucleoside deaminase is present in human leukocytes. Some of its properties are described.