ASSESSMENT OF INDIVIDUAL PROTEIN-TURNOVER IN 3 MUSCLE TYPES OF RAINBOW-TROUT

Protein synthesis rate was measured in three different muscle types which are ranked as follows: white skeletal muscle < red skeletal muscle < heart. The protein synthesis rates of mitochondrial and nuclear fractions were similar or slightly higher (white muscle) than those of whole tissue protein. The myofibrillar fraction accounted for 64%, 60% and 50% of the total protein in white muscle, red muscle and heart. The fractional rate of protein synthesis in the myofibrillar fraction is similar or slightly lower (red muscle) than that of whole muscle protein, Protein synthesis rates of individual proteins, myosin and actin, were similar to that of the myofibrillar fraction.