Preferential binding of beta C relative to beta S globin to stroma in hemoglobin SC disease

Globin synthesis was measured in blood samples of four patients with hemoglobin SC Disease. In the stroma-free supernatant, globin synthesis was balanced with alpha/(beta S + beta C) = 1. In the exhaustively washed stroma, there was a preferential binding of beta chains to stroma, similar to that reported for Sickle Cell Anemia. However, while the beta S/beta C ratio was balanced in the supernatant (0.8-0.9), the beta S/beta C ratio of the stroma varied from 0.2 to 0.4. Therefore, beta C is bound to stroma in preference to beta S in hemoglobin SC disease. These findings are consistent with the concept that binding of globin to stroma is related to the electrophoretic charge of the hemoglobin.