PROTEINS AND NUCLEIC ACIDS IN SOLUTION 53 



was suspended at 4 to 5°C in 0-1 per cent RNA solution (Merck prepar- 

 ation, M = 26,000) in acetate buffer (0-1 M; pH3-7). Under these condi- 

 tions each grain of enzyme powder was covered with a thin surface 

 layer of ribonucleoprotein (RNP) which enveloped the grain and inhib- 

 ited its further dissolution. The suspension thus obtained was centrifuged 

 and the supernatant poured off and replaced by the same buffer, the 

 suspension was then stirred again and the process repeated two or three 

 times to wash away all the excess RNA. The pure enzyme suspension in 

 acetate buffer thus obtained was stabilized by a thin surface layer of 

 RNA with particles of a diameter of 0-4 to l-O ir (Fig. 1). The nitrogen 

 and phosphorus contents were determined. The N/P ratio in the pre- 

 cipitate of the suspension was 6-5; since all the phosphorus belonged to 

 RNA, while the nitrogen contriljuted 13-2 per cent in protein 

 and 14-5 per cent in RNA, then from the values of N and P the RNA 



y 



Fig. 1 



