Cell-free Hemoglobin Synthesis

Abstract

Abstract A cell-free protein-synthesizing system derived from rabbit reticulocytes is described which is dependent on the addition of transfer RNA for the translation of endogenous hemoglobin messenger RNA. Product analysis indicates that the system is active in the initiation of new chains. When hemoglobin is synthesized in the presence of a limiting amount of tRNA, there is a 50% decrease in α chain production relative to β chain production. Deacylated rabbit liver tRNA can, but deacylated Escherichia coli tRNA cannot, be substituted for rabbit reticulocyte tRNA in the synthesis of hemoglobin.