PROTEIN-SYNTHESIS AND OXYGEN-CONSUMPTION IN FISH CELLS

Oxygen consumption and protein synthesis were measured concurrently in four fish cell types: BF-2 and RTG-2 cell lines, rainbow trout macrophages and scale cells. The fractional rates of protein synthesis (percentage of the protein mass synthesised per day) were ranked: BF-2 cells > macrophages > RTG-2 cells > scale cells. Oxygen consumption rates were ranked BF-2 cells = macrophages = RTG-2 cells > scale cells. Within three of the cell types (BF-2, RTG-2 and scale cells) oxygen consumption and protein synthesis were linearly correlated, whereas comparison between the four cell types gave rise to an exponential relationship between fractional rates of protein synthesis and oxygen consumption. Inhibition of protein synthesis with cycloheximide by 41-65% resulted in a 62-89% reduction in oxygen consumption depending on cell type. Calculations of the aerobic cost of protein synthesis using the cycloheximide-sensitive protein synthesis and oxygen consumption rates resulted in estimates ranging from 11 to 217 mu mol O-2 . mg protein(-1) synthesised depending on the cell type. The lowest net protein synthesis costs, which are close to theoretical values for peptide bond formation, were associated with the most rapid rates of protein synthesis.