Additional biochemical studies on erythrocytes containing hemoglobin Sabine

Additional studies have been carried out on erythrocytes containing an unstable hemoglobin (Sabine). Increased levels of hexokinase and glyceraldehyde phosphate dehydrogenase, together with a high intracellular inorganic phosphate level and a high ADP ATP ratio, account for the very rapid glycolytic rate in these cells. The high intracellular inorganic phosphate level appears to be a consequence of increased uptake of phosphate into the cells, with uptake coupled to activities of two membrane enzymes, glyceraldehyde phosphate dehydrogenase and phosphoglycerate kinase. In vitro incubation studies over a period of 14 hours indicate that these cells maintain intracellular K⁺ and Na⁺ levels satisfactorily. These studies do not, however, indicate whether rates of influx or efflux of these cations are modified in these abnormal erythrocytes.