ATPase in oxidative phosphorylation 251 



this latency phenomenon and you develop yourATP-ase activity, is this preparation 

 capable of restoring phosphorylation even after the latent ATP-ase has appeared ? 



Pullman : Yes, it always maintains its coupling activity. The only discrepancy 

 with regard to the two activities is that during purification the ATP-ase is "acti- 

 vated" while the coupling activity is not. 



Packer : It is interesting that the nucleotide specificity for ATP-ase is also very 

 similar to that for actomyosin, namely that the all four nucleotides catalyze the 

 reaction, but only the ATP-ase is DNP-stimulated. These are similar to the pro- 

 perties of actomyosin B as reported by Blum and Alorales. 



Pullman : Yes, there is a remarkable parallelism between the mitochondrial 

 ATP-ase and myosin ATP-ase. However, I think that in the case of myosin, the 

 hydrolysis of some of the other triphosphonucleosides is also stimulated by DNP 

 or is that what you said ? 



Packer: I only wish to comment that there are remarkable similarities between 

 this ATP-ase and actomyosin and it would appear that your enzyme may be a very 

 prorpising choice as the mechano-protein which has received so much discussion 

 this afternoon. 



