When erythrocytes are exposed to
hypoxia,
hemoglobin (Hb) stabilizes in the T-state by capturing
2,3-bisphosphoglycerate. This process could reduce the intracellular pool of glycolytic substrates, jeopardizing cellular energetics. Recent observations suggest that
hypoxia-induced activation of glycolytic
enzymes is correlated with their release from Band III (BIII) on the cell membrane. Based on these data, we developed a mathematical model of erythrocyte metabolism and compared
hypoxia-induced differences in predicted activities of the
enzymes, their products, and cellular energetics between models with and without the interaction of Hb with BIII. The models predicted that the allostery-dependent Hb interaction with BIII accelerates consumption of upstream glycolytic substrates such as
glucose 6-phosphate and increases downstream products such as
phosphoenolpyruvate. This prediction was consistent with metabolomic data from capillary electrophoresis mass spectrometry. The
hypoxia-induced alterations in the metabolites resulted from acceleration of glycolysis, as judged by increased conversion of [(13)C]
glucose to [(13)C]
lactate. The allostery-dependent interaction of Hb with BIII appeared to contribute not only to maintenance of energy charge but also to further synthesis of
2,3-bisphosphoglycerate, which could help sustain stabilization of T-state Hb during
hypoxia. Furthermore, such an activation of glycolysis was not observed when Hb was stabilized in R-state by treating the cells with CO. These results suggest that Hb allostery in erythrocytes serves as an O(2)-sensing trigger that drives glycolytic acceleration to stabilize intracellular energetics and promote the ability to release O(2) from the cells.