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 macrop hages and scale cells. The fractional rates of protein synthesis (perc entage of the protein mass synthesised per day) were ranked: BF-2 cell s > macrophages > RTG-2 cells > scale cells. Oxygen consumption rates were ranked BF-2 cells = macrophages = RTG-2 cells > scale cells. With in three of the cell types (BF-2, RTG-2 and scale cells) oxygen consum ption and protein synthesis were linearly correlated, whereas comparis on between the four cell types gave rise to an exponential relationshi p between fractional rates of protein synthesis and oxygen consumption . Inhibition of protein synthesis with cycloheximide by 41-65% resulte d in a 62-89% reduction in oxygen consumption depending on cell type. Calculations of the aerobic cost of protein synthesis using the cycloh eximide-sensitive protein synthesis and oxygen consumption rates resul ted in estimates ranging from 11 to 217 mu mol O-2 . mg protein(-1) sy nthesised depending on the cell type. The lowest net protein synthesis costs, which are close to theoretical values for peptide bond formati on, were associated with the most rapid rates of protein synthesis.