| Autor: |
Livshits L; Department of Applied Physics, The Hebrew University of Jerusalem, Givat Ram, Jerusalem 91904, Israel., Caduff A, Talary MS, Lutz HU, Hayashi Y, Puzenko A, Shendrik A, Feldman Y |
| Jazyk: |
angličtina |
| Zdroj: |
The journal of physical chemistry. B [J Phys Chem B] 2009 Feb 19; Vol. 113 (7), pp. 2212-20. |
| DOI: |
10.1021/jp808721w |
| Abstrakt: |
We propose a key role for the glucose transporter 1 (GLUT1) in mediating the observed changes in the dielectric properties of human erythrocyte membranes as determined by dielectric spectroscopy. Cytochalasin B, a GLUT1 transport inhibitor, abolished the membrane capacitance changes in glucose-exposed red cells. Surprisingly, D-fructose, known to be transported primarily by GLUT5, exerted similar membrane capacitance changes at increasing D-fructose concentrations. In order to evaluate whether the glucose-mediated membrane capacitance changes originated directly from intracellularly bound adenosine triphosphate (ATP) or other components of the glycolysis process, we studied the dielectric responses of swollen erythrocytes with a decreased ATP content and of nucleotide-filled ghosts. Resealed ghosts containing physiological concentrations of ATP yielded the same glucose-dependent capacitance changes as biconcave intact red blood cells, further supporting the finding that ATP is the effector of the glucose-mediated dielectric response where the ATP concentration is also the mediating factor in swollen red blood cells. The results suggest that ATP binding to GLUT1 elicits a membrane capacitance change that increases with the applied concentration gradient of D-glucose. A simplified model of the membrane capacitance alteration with glucose uptake is proposed. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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