A kinetic model of protein synthesis. Application to hemoglobin synthesis and translational control

We present a kinetic model of protein synthesis which encompasses initiation, elongation, and termination parameters. We have investigated the dependence of the total rate of protein synthesis and the size of the translating polysomes on each of these parameters and in particular on the level of active 40 S ribosomes and initiation factors. This model qualitatively fits experimental data for the ratio of alpha- to beta-globin synthesis in reticulocytes, both under normal conditions and in the presence of inhibitors of chain initiation. This model has also been used to examine the effect that limiting amounts of certain tRNAs might have on the total rate of protein synthesis. In addition, the role of initiation factor discrimination and mRNA length are examined with respect to the differential translation of mRNAs.