Synthesis of a Brain-Specific Protein (S100 Protein) in a Homologous Cell-Free System Programmed with Cerebral Polysomal Messenger RNA
Abstract
Polyribosomes, carrying nascent polypeptide chains, were prepared from whole brain, cortex, and hindbrain-medullary white matter of young adult rats. In a homologous cell-free system, a brain-specific protein (S100 protein) was identified in the mixture of polypeptides released from the polyribosomes during incubation for 1 hr at 37°. De novo synthesis of the S100 protein was achieved in a reconstituted cerebral cell-free system containing polysome-derived mRNA and 40S + 60S subunits. The radioactively labeled S100 protein synthesized in vitro was identified by precipitation with antibody to S100 after addition of purified S100 as a carrier, and migration of the solubilized precipitate on acrylamide gels in the presence of sodium dodecyl sulfate. In vitro synthesis of the S100 protein did not occur in analogous cell-free systems derived from hepatic tissue or in a heterologous system containing liver polyribosomes and cerebral enzymes.
- Publication:
-
Proceedings of the National Academy of Science
- Pub Date:
- August 1972
- DOI:
- 10.1073/pnas.69.8.2326
- Bibcode:
- 1972PNAS...69.2326Z