Cell-free translation and partial characterization of proenkephalin messenger RNA from bovine striatum

Abstract

Summary The biosynthesis of the primary precursor of the enkephalins (proenkephalin) was investigated by cell-free translation of bovine striatum polyadenylated RNA. 35 S-Labeled proteins encoded by striatum mRNA were digested with trypsin and carboxypeptidase B, and released [ 35 S]Met-enkephalin was identified by immunoprecipitation and high-performance liquid chromatography. The apparent molecular weight of putative proenkephalin synthesized in cell-free systems was found to be M r 31,000 ± 1000. Digestion of cell-free translated 3 H-labeled proteins of M r 31,000 ± 3000 yielded both [ 3 H]Metenkephalin and [ 3 H]Leu-enkephalin. Putative proenkephalin mRNA of striatum was found to be 1450 ± 200 nucleotides in length.