242 PHILIP SIEKEVITZ 



TABLE I 



Release of Amylase Activity from RNP Particles by Spermine, 

 Various other Amines, and Various other Compounds 



Incubation conditions are given in the text. Per cent release is that percentage 

 of amylase activity which was rendered soluble after spinning the incubated 

 particles for 90 min. at 105 000 x g. Each figure represents one experiment. 



* Incubated at o"" = 83. 

 t Plus 10-3 m Mg + + = 96. 

 t Plus IO-' M Mg + + = 77. 

 § Incubated at o"" = 32. 



spermine only discharges a small amount of the RNA of the particles, and 

 in fact, the ratio, RNA /protein, of the spermine-treated particles is the 

 same or even higher than that of the particles incubated in water. In con- 

 tradistinction, the P-P treated particles have an RNA /protein ratio of one- 

 half (Table II), or even lower [7] than, that of the control particles. How- 

 ever, spermine, like P-P, releases nearly all the Mg + + of the particles 

 into solution. Putrescine, at io~^ m, behaves similarly to spermine at 5 x 

 io~* M or at io~* M, but at 2 x io~^ m putrescine begins to disrupt the 

 particles so that some of the RNA is released. 



The reason given previously for the action of the pyrophosphate 

 compounds was that these compounds effectively compete with the 

 phosphate groups of the RNA for the Mg + + complexed to these groups. 

 Thus, the addition of Mg + + to the incubation medium along with the 

 pyrophosphate compounds nullifies the effect of these compounds [7]. 

 However, when Mg + + was added with the spermine, it did not counteract 

 the effect of spermine on amylase release (cf. footnote. Table I). In fact, 

 it was uniformly found that in the presence of both Mg + + and spermine, 



