THE NATURE OF THE AMINO ACID POOL USED FOR PROTEIN SYNTHESIS IN RAT BRAIN SLICES
Corresponding Author
M. E. A. Reith
Division of Molecular Neurobiology, Rudolf Magnus Institute for Pharmacology and Laboratory for Physiological Chemistry, Medical Faculty, Institute of Molecular Biology, Padualaan 8, Utrecht, The Netherlands
To whom correspondence should be sent. Present address: Institute of Neurochemistry, Ward's Island, New York 10035, U.S.A.Search for more papers by this authorP. Schotman
Division of Molecular Neurobiology, Rudolf Magnus Institute for Pharmacology and Laboratory for Physiological Chemistry, Medical Faculty, Institute of Molecular Biology, Padualaan 8, Utrecht, The Netherlands
Search for more papers by this authorB. J. van Zwietek
Division of Molecular Neurobiology, Rudolf Magnus Institute for Pharmacology and Laboratory for Physiological Chemistry, Medical Faculty, Institute of Molecular Biology, Padualaan 8, Utrecht, The Netherlands
Search for more papers by this authorW. H. Gispen
Division of Molecular Neurobiology, Rudolf Magnus Institute for Pharmacology and Laboratory for Physiological Chemistry, Medical Faculty, Institute of Molecular Biology, Padualaan 8, Utrecht, The Netherlands
Search for more papers by this authorCorresponding Author
M. E. A. Reith
Division of Molecular Neurobiology, Rudolf Magnus Institute for Pharmacology and Laboratory for Physiological Chemistry, Medical Faculty, Institute of Molecular Biology, Padualaan 8, Utrecht, The Netherlands
To whom correspondence should be sent. Present address: Institute of Neurochemistry, Ward's Island, New York 10035, U.S.A.Search for more papers by this authorP. Schotman
Division of Molecular Neurobiology, Rudolf Magnus Institute for Pharmacology and Laboratory for Physiological Chemistry, Medical Faculty, Institute of Molecular Biology, Padualaan 8, Utrecht, The Netherlands
Search for more papers by this authorB. J. van Zwietek
Division of Molecular Neurobiology, Rudolf Magnus Institute for Pharmacology and Laboratory for Physiological Chemistry, Medical Faculty, Institute of Molecular Biology, Padualaan 8, Utrecht, The Netherlands
Search for more papers by this authorW. H. Gispen
Division of Molecular Neurobiology, Rudolf Magnus Institute for Pharmacology and Laboratory for Physiological Chemistry, Medical Faculty, Institute of Molecular Biology, Padualaan 8, Utrecht, The Netherlands
Search for more papers by this authorAbstract—
The incorporation into brain slice protein of externally provided [1-14C]valine was measured at varying levels of valine in the medium, under conditions of constant protein synthesis and equilibration of intracellular valine specific activity. The results indicate that the valine pool used for protein synthesis is not identical to the pool of total free valine. Neither does the incorporation solely occur from an extracellular pool which is in equilibrium with the incubation medium. The data are compatible with a two-site activation model in which aminoacylation of tRNA occurs at both an internal site utilizing amino acid from the intracellular pool and an external (possibly membranous) site converting extracellular valine directly to valyl-tRNA. A good fit to the experimental observations is also provided by a compartmented intracellular valine pool model.
Abbreviations used:
-
- SSA
-
- sulphosalicylic acid
-
- HEPES
-
- N-2-hydroxyethyl piperazine N1-2-ethane sulphonic acid
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