ACID-EXTRACTABLE AMINO-ACID POOL IN ESCHERICHIA-COLI - POSSIBLE ROLE IN ENERGY-INDEPENDENT AMINO-ACID ACCUMULATION AND PROTEIN-SYNTHESIS

The acid extractable amino acid pool (AEP) demonstrates time and conce ntration dependent saturation kinetics in cold-incubated (0-2 degrees C) Escherichia coli cells. Attention is drawn in particular to the con tribution of the AEP to the total noncovalently bound amino acid intra cellular levels (total pool) at low exogenous amino acid concentration s. Amino acids compete with one another for associations which interna lly constitute the AEP. Although physicochemically related amino acids tend to be better competitors than other amino acids, the physicochem ical relatedness was by no means the sole, or necessarily the main, fa ctor determining competitiveness. On the return of cells to incubation temperatures allowing protein synthesis to proceed, the contribution of the AEP to protein synthesis was explored.