EFFECTS OF SPERMINE ON THE RIBONUCLEOPROTEIN PARTICLES 243 



TABLE II 



Effect of Various Amines and Inorganic Pyrophosphate 

 ON THE Release of RNA, Protein, and Mg + + from RNP Particles 



Incubation conditions are given in the text. 



Exp. 



No. 



Compound added 



Left in RNP particles after spinning incu- 

 bated particles for 90 min. at 105 000 x g 



None 



Inorg. Pyrophos. (5 x 10"* m) 140 

 Spermine (10 * m) 

 Tris, pH 7-0 (lo"^ m) 



None 915 



Inorg. Pyrophos. (5 x io~* m) 456 



Spermine (10"* m) 935 



Putrescine (io~^ m) 920 



None 289 



Spermine (10^^ m) 272 

 Spermine (10* m) plus Mg + + 



(io~^ m) 321 



0-08 



002 



the RNA /protein ratios of the incubated particles were the same or in 

 most cases higher than those of either the untreated particles or the 

 particles treated with spermine alone (Table III). This might be related to 

 the observation that in the presence of Mg + + in the medium, spermine 

 did not release the Mg + + from the particles (Table II, Exp. 6). 



From the results of the above experiments, it would appear that the 

 action of the various amines, particularly spermine, can be described as 

 follows. Spermine replaces the Mg + + complexed to the phosphate groups 

 of the RNA of the particles by forming a strong salt bond between its 

 charged amine groups and the charged phosphate groups of the RNA. 

 This salt bond is stronger than the Mg + +-phosphate complex. The 



