io8 



PETER REICHARD 



diphosphates and is inhibited by an excess of ATP, which increases the 

 level of triphosphates but decreases the diphosphate level. 



As mentioned earlier, the synthesis of DNA from one labelled deoxy- 

 nucleotide was stimulated by the addition of the three other non-labelled 



MxlO^ 



Fig. 6. Influence of an equimolar mixture of TTP, dATP and dGTP on 

 DNA formation from dCMP and CMP, respectively. 



20 

 MxIQS 



30 



Fig. 7. Comparison of different deoxynucleoside triphosphates as inhibitors of 

 DNA formation from CMP. 



deoxynucleoside triphosphate. This is demonstrated for [^^C]-dCMP by 

 the upper curve of Fig. 6. With P^C]-CMP, however, isotope incorporation 

 into DNA was strongly inhibited by the addition of an equimolar mixture 

 of the triphosphates of thymidine, deoxyadenosine and deoxyguanosine 



