The activity of rabbit muscle phosphofructokinase was inhibited by transfer ribonucleic acid. This inhibition was reduced by inclusion of an aminoacyl-tRNA charging system. The results explain the loss of ATP in amino acid deprived cells, the significance of the critical role of fructose-1,6-diphosphate in peptide chain initiation, and other phenomena dependent upon this interaction between the protein synthetic and glycolytic systems.