HEMOGLOBIN SYNTHESIS IN RABBIT RETICULOCYTES IN VITRO

Abstract

We have reported the rapid incorporation of labeled amino acids into the proteins of rabbit reticulocytes in vitro and the stimulation of this process by certain amino acids, iron, fructose-amino acids, glucose, and some, as yet, unidentified material in the filtrate of boiled plasma. The incorporation was measured in the mixture of the total proteins of the reticulocytes (1, 2). In the study reported here two protein fractions were isolated, the hemoglobin, which comprises more than 75 per cent of the total, and the water-insoluble proteins. The hemoglobin was fractionated into heme and globin. Experiments were carried out with four C^(14)-labeled amino acids and with different stimulators to ascertain whether heme synthesis and amino acid incorporation went parallel or not.