Studies of In Vitro Synthesis of Heterogenic Hemoglobins*

In addition to the difficulties caused by in-creased hemolysis of peripheral red cells, patients with various hemoglobinopathies suffer from a limited capacity to synthesize hemoglobin (1). In recent years a great deal of investigative ef-fort, especially in the field of microbial genetics, has been devoted to the nature of the induction-repression processes that control the rate of syn-thesis of specific proteins (2, 3). Relatively little information, however, is available concern-ing the quantitative effects of a structural gene mutation on the synthesis of a given protein. As an initial approach to this problem, studies of the relationship between the synthetic rates of heterogenic hemoglobins and the amounts of such hemoglobins in the peripheral blood were under-taken. The results indicate that the two hemo-globins are synthesized at different rates. Fur-thermore, in the cases studied here, the synthetic rates were proportional to the ratio of the amounts of the two hemoglobins in the peripheral blood. These heterogenic hemoglobin synthesizing sys-tems were equally stable under a wide variety of metabolic conditions. Methods Six patients with hemoglobinopathies were studied: two with SC hemoglobin, two with SA hemoglobin, one with CA hemoglobin, and one with DA hemoglobin. All patients were well at the time of the study except one (D.M.) with SC disease who was in a painful crisis. The hemoglobin types S, C, and A were verified by paper electrophoresis in barbital buffer at pH 8.6 (4) and the D hemoglobin by agar gel electrophoresis (5). An attempt was made to induce marrow erythroid stimula-tion in four of the subjects by phlebotomy of 1 U of blood daily for 2 consecutive days. For each study approximately 50 ml of peripheral blood was obtained by venipuncture and collected di-rectly into tubes containing about 1 mg of heparin for