The active center of transport for phosphoenolpyruvate and inorganic phosphate in the human erythrocyte membrane.

Phosphoenolpyruvate is transported into erythrocytes by a carrier-mediated transport system. The transport is competitively inhibited by inorganic phosphate and pyridoxal phosphate, which are transported across the cell membrane by Band 3. The pH profiles for the transport of inorganic phosphate and phosphoenolpyruvate suggest that a histidine residue exposed at the inner surface of the membrane participates in both of the transport. A hydrophobic peptide which may be a part of the active center for the transport is purified from the CNBr fragments of Band 3.