Cell-free synthesis of cod preproinsulin.
Poly(A)-containing ribonucleic acid from cod islet greatly stimulated the incorporation of radioactive amino acids into proteins when assayed in a wheat germ translation system. The translation products were examined by specific immunoprecipitation with guinea pig anti cod insulin antibodies and by extraction with acid--ethanol. These measurements revealed at least a fivefold increase in incorporation of labelled amino acid over the nonprogrammed system. Sodium dodecyl sulfate disc gel electrophoresis and gel filtration chromatography showed a product of molecular weight 12 500, a size considerably larger than cod proinsulin (9000). It is concluded that cod proinsulin is synthesized via a larger precursor, preproinsulin.
D000818:Animals; D002474:Cell-Free System; D005399:Fishes; D008970:Molecular Weight; D011132:Polyribosomes / Q000378:metabolism; D011384:Proinsulin / Q000096:biosynthesis*; D014176:Protein Biosynthesis
D011384:Proinsulin