. Biological structure and function; proceedings. Biochemistry; Cytology. STUDIES ON THE INCORPORATION OF ARGININE 305 formation of arginine-RNA is independent of arginine concentrations above o • i mM. As a qualitative test of the product formed, a sample of acceptor RNA from 30S0A5 was labelled with the more active of the ["C]-arginine preparations (see Methods and Materials). The labelled RNA obtained had a specific activity of 5730 It was subjected to mild alkaline treatment (0-05 M triethylamine for 3 min. at 60°) and analyzed by paper chromatography. Only the arginine sp
. Biological structure and function; proceedings. Biochemistry; Cytology. STUDIES ON THE INCORPORATION OF ARGININE 305 formation of arginine-RNA is independent of arginine concentrations above o • i mM. As a qualitative test of the product formed, a sample of acceptor RNA from 30S0A5 was labelled with the more active of the ["C]-arginine preparations (see Methods and Materials). The labelled RNA obtained had a specific activity of 5730 It was subjected to mild alkaline treatment (0-05 M triethylamine for 3 min. at 60°) and analyzed by paper chromatography. Only the arginine spot could be detected, despite the fact that the arginine used for the incorporation experiment showed four spots of impurities. The hydrolysis of arginine-RNA at pH 8-o was studied at three temperatures. Samples of p^C]-arginine-RNA with 160 were incubated at different temperatures; aliquots were removed at various. Fig. 5. 20 30 40 50 60 Time (min) Rate of hydrolysis of arginine-RNA at pH 8 -o and different temperatures. times and added to i ml. of cold o-oi M lanthanum nitrate in 0-5 M per- chloric acid. The precipitate collected after centrifugation was counted. Figure 5 shows these data as a percentage of the counts of the zero time precipitate. Discussion THE ARGININE-ACTIVATING ENZYME The chromatography of the arginine-activating enzyme described here removes nucleic acid rather well but gives on a protein basis only about a threefold increase in specific activity. However, the amount of protein required to label i mg. of RNA in 15 min. is only 15 fig. (see Fig. 4). The corresponding figure for a seven-times purified leucine-activating enzyme calculated from Fig. 3 in ref. [16] was found to be around 4-7 mg. A similar figure has been reported also for an isoleucine-activating protein. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations m
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