232 



WALDO E. COHN 



of riboflavin phosphate is ascribed to its added nonpolar affinity.) The 

 factors discussed in Section III. 1.6 may cause some shifting of the order of 

 elution in other pH ranges. 



< 0.6- 



■ 



LITERS THROUGH COLUMN 



Fig. 16. Analysis of snake venom diesterase digest of PNA by anion exchange." 

 Exchanger: Dowex-1 -formate, 400 mesh, 5.8 cm. X 0.9 cm.''. 

 Solutions: as shown, at 0.5 ml./min. 



Sorbed material: 16 mg. calf liver PNA + 1 ml. 0.05 M MgCh + 1 ml. snake 

 venom diesterase preparation (rattlesnake venom freed of 5' monoesterase by 

 the m.ethod of Butler"), total volume 5 ml.; pH 8.6 maintained by addition of 0.02 

 A^ NaOH for 7 hr. at 25°C.; diluted to 100 ml. with 1 meq. NH4OH; sorbed. 



h. Polyphosphates 



Similarly, ATP follows uridine-3' , 5'-diphosphate (and also uridine-5'- 

 pyrophosphate^^) , and it has been demonstrated^'' that the entire group of 

 triphosphorylated nucleosides may be separated from the diphosphorylated 

 ones as well as the latter are from the monophosphates. The great differ- 

 ence in affinity has been exploited to effect rapid separations of adenosine- 

 5'-phosphate from ADP and ATP." 



Finally, the position of hexametaphosphate may be noted in Fig. 17 as 

 further evidence that gross affinity increases with the degree of polyvalency 

 of the ion involved. 



'' R. B. Hurlbert, and V. R. Potter, J. Biol. Chem. 209, 1 (1954). 

 « W. E. Cohn and C. E. Carter, J. Am. Chem. Soc. 72, 4273 (1950). 



