Stimulation of enzyme induction by 5-amino-2, 4-bis(substituted-amino)pyrimidines.

Several investigators (Creaser, 1955; Pardee, 1955; Spiegelman et al., 1955; Horowitz et al., 1958) have shown inhibition of enzyme induction by pyrimidine and purine analogues. The inhibition results apparently from interference with nucleic acid synthesis. In experiments with other compounds which might interfere with nucleic acid metabolism, we found a stimulation of enzyme induction in Escherichia coli with certain 5-amino-2,-bis(substituted-amino)pyrimidines. Experiments are presented in this paper which show that the mechanism of stimulation of enzyme induction is related to enzyme formation rather than to enzyme activation or to the stimulation of the transport of the enzyme inducer into the cell. In another paper (Kunkee, 1960a), results with bacterial mutants are presented to show at what step in the enzyme induction scheme the stimulation probably occurs.