Phosphoribosylpyrophosphate (PRPP) is essential for the formation of both
purine and
pyrimidine nucleotides as well as for the active
nucleotide form of some chemotherapeutic agents. The formation of PRPP is catalyzed by by
enzyme PRPP synthetase, and many different compounds are known to affect the activity of this
enzyme. This report examines the effects of endogenous
purine and
pyrimidine nucleotides,
nucleosides, and several analogs of these compounds on the activity of
PRPP synthetase from different types of normal and leukemic white blood cells (i.e. normal lymphocytes, normal granulocytes,
phytohemagglutinin-stimulated lymphocytes, and acute and chronic leukemic cells). Our results show that the effect varied with each individual compound, and the magnitude of the effect was dependent on the source of the
enzyme. Since it appears possible to differentially affect
PRPP synthetase activity from the different types of leukemic cells, this
enzyme may be a potential target site in the
chemotherapy of
leukemia.