Protein synthesis in vitro by epaxial muscle polyribosomes from cod, gadus morhua

1. Ribosomes were isolated from epaxial muscle of cod (Godus morhua). 2. Incorporation of amino acids into protein was determined in systems containing liver cell sap from rat or rainbow trout (Salmo gairdneri R.). Maximal rates were at 35 degrees and 28 degrees C, respectively. The optimum pH was between 7.5 and 8.0. 3. Ribosomes isolated from muscle stored at -80 degrees C between 1 and 14 days retained 86% of the activity of ribosomes from fresh tissue. 4. Starvation of fish for 10 days reduced amino acid incorporating activity of isolated ribosomes to 15-20%. 5. All ribosome preparations used in the experiments were analysed by sucrose density gradient centrifugations.