Glucose affinity for the glucose transporter Glut1 in native or reconstituted lipid bilayers. Temperature-dependence study by biomembrane affinity chromatography.
The affinity of D-glucose and the transport inhibitor cytochalasin B (CB) for the glucose transporter Glut1 was studied at 5-42 degrees C by quantitative frontal affinity chromatography on sterically immobilized human red cell membrane vesicles, and on proteoliposomes containing reconstituted red cell membrane proteins. Glut1 in the vesicles showed the highest glucose affinity; the dissociation constant Kd(glc) was nearly constant (16 +/- 3 mM) from 15 degrees C to 37 degrees C. For Glut1 in proteoliposomes Kd(glc) decreased from 56 mM at 5 degrees C to 26 mM at 42 degrees C. The CB-Glut1 affinity was strongest around 20 degrees C and was mostly higher with the vesicles, Kd (CB) being 49 nM at 19 degrees C. The entropy and entropy and enthalpy changes for the interactions were calculated.
Lundqvist
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A
Department of Biochemistry, Uppsala University, Sweden.
Lundahl
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P
D000328:Adult; D002846:Chromatography, Affinity; D004910:Erythrocyte Membrane / Q000201:enzymology; D005947:Glucose / Q000737:chemistry*; D051272:Glucose Transporter Type 1; D006801:Humans; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008024:Ligands; D008051:Lipid Bilayers / Q000737:chemistry*; D008081:Liposomes; D008566:Membranes; D009004:Monosaccharide Transport Proteins / Q000737:chemistry*; D013696:Temperature; D013816:Thermodynamics
D051272:Glucose Transporter Type 1; D008024:Ligands; D008051:Lipid Bilayers; D008081:Liposomes; D009004:Monosaccharide Transport Proteins; C495677:SLC2A1 protein, human; D005947:Glucose