title: Effects of ATP depletion on the mechanism of hexose transport in intact human erythrocytes.
abstract: Depletion of ATP is known to inhibit glucose transport in human erythrocytes, but the kinetic mechanism of this effect is controversial. Selective ATP depletion of human erythrocytes by 10 micrograms/ml A23187 in the presence of extracellular calcium inhibited 3-O-methylglucose influx noncompetitively and efflux competitively. ATP depletion also decreased the ability of either equilibrated 3-O-methylglucose or extracellular maltose to inhibit cytochalasin B binding in intact cells, whereas neither total high-affinity cytochalasin B binding nor its Kd was affected. Under the one-site model of hexose transport these data indicate that ATP depletion decreases both the affinity of the inward-facing glucose carrier for substrate and its ability to reorient outwardly in intact cells.
mesh_terms: D019325:3-O-Methylglucose; D000255:Adenosine Triphosphate / Q000097:blood*; D000001:Calcimycin / Q000494:pharmacology; D003571:Cytochalasin B / Q000097:blood; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D008320:Maltose / Q000097:blood; D008757:Methylglucosides / Q000097:blood; D009004:Monosaccharide Transport Proteins / Q000097:blood*
chemical_list: D008757:Methylglucosides; D009004:Monosaccharide Transport Proteins; D019325:3-O-Methylglucose; D000001:Calcimycin; D003571:Cytochalasin B; D008320:Maltose; D000255:Adenosine Triphosphate