Control of hemoglobin synthesis by oxygen tension in a cell-free system

Abstract

The effect of oxygen concentration and heme on hemoglobin synthesis has been studied in avian erythrocyte nuclei. These studies show that concentrations of oxygen higher or lower than 10–15% ( v v ) inhibit the incorporation of C 14-labeled amino acid into protein. This inhibition can be relieved by the addition of heme. The incorporation of Fe 59 heme is inversely related to oxygen concentration and parallels the inhibition of protein synthesis by concentrations of oxygen over 5%. Heme or protoporphyrin and iron stimulate significantly the incorporation of amino acids into globin, and heme synthesis appears to be limiting for protein synthesis in this system. These findings are compatible with a model whereby oxygen concentration regulates the synthesis of heme, which in turn controls the synthesis of globin.