192 



S. Spiegelman 



Table III 



The Effect of RNAse on Enzyme Synthesis and DNA and RNA Content 



RNAse (500 (jig./ml.) was present in the experimental flasks during proto- 

 plast formation (45 minutes). Protoplasts were then recovered by centrifuga- 

 tion and washed. An aliquot was used for determination of DNA, RNA and 

 protein. The extent of removal of each nucleic acid is determined in terms of 

 ratio to protein in the protoplast pellet and comparison with untreated 

 control. This corrects for loss due to lysis during treatment. Enzyme-forming 

 ability is examined with another aliquot of the protoplasts which is resus- 

 pended in an induction mixture (0-5M-K2HPO4, pH 7-8; 2% amino acids, 

 0-6% hexose diphosphate, and 06m lactose). Samples are removed periodi- 

 cally for enzyme assay. Enzyme activity is determined in terms of the m^xM of 

 0- nitrophenyl-p-D-galactoside hydrolysed per mg. protein per minute. The 

 rate of enzyme formation is obtained as the number of enzyme activity units 

 synthesized per mg. protein per hour. 



the conclusions derived from the study of other subcellular 

 systems, such as those developed by Gale and Folkes (1955a 

 and h) and by Zamecnik and his collaborators (Zamecnik and 

 Keller, 1954). They suggest that the molecular integrity of 

 RNA is essential for the synthesis of new protein molecules. 



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Brenner, S. (1955). Biochim. biophys. acta, 18, 531. 



Brenner, S., and Stent, G. S. (1955). Biochim. biophys. acta, 17, 473. 



Gale, E. F., and Folkes, J. P. (1955a). Biochem. J., 59, 661. 



Gale, E. F., and Folkes, J. P. (19556). Biochem. J., 59, 675. 



Hardwick, W. a., and Foster, J. W. (1952). J. gen. Physiol., 35, 907. 



