A soluble preparation from rat brain that incorporates into its own proteins ( 14 C)arginine by a ribonuclease-sensitive system and ( 14 C)tyrosine by a ribonuclease-insensitive system.

Age Factors Amino Acids/metabolism Amino Acyl-tRNA Synthetases/metabolism Animals Arginine/metabolism Brain/enzymology,metabolism Brain Chemistry Carbon Isotopes Chemical Phenomena Chemistry Kidney/metabolism Kinetics Liver/metabolism Pronase Protein Biosynthesis Proteins/analysis RNA, Transfer/metabolism Rats Ribonucleases/metabolism Thyroid Gland/metabolism Time Factors Tritium Trypsin Tyrosine/metabolism Valine/metabolism

Amino Acids Carbon Isotopes Proteins Tritium Tyrosine RNA, Transfer Arginine Ribonucleases Trypsin Pronase Amino Acyl-tRNA Synthetases Valine