Chromatography on cells: analyses of solute interactions with the glucose transporter Glut1 in human red cells adsorbed on lectin-gel beads

The affinities of the human red cell glucose transporter Glut1 for D-glucose and cytochalasin B (CB) and the stoichiometry of CB binding vary with the Glut1 environment. In order to study the native state of Glut1 we adsorbed human red cells to wheat germ lectin agarose gel beads for frontal affinity chromatographic analyses. Glut1 showed relatively high affinities for D-glucose (Kd 12±1 mM) and CB (Kd 59±17 nM). The number of CB-binding sites per Glut1 monomer, 0.46±0.16, was approximately doubled upon coating the cells with polylysine, which induced cell association.