Identification of the D-glucose binding polypeptide of the renal Na +-D-glucose cotransporter with a covalently binding D-glucose analog

Abstract

The covalently binding D-glucose analog 10- N-(bromoacetyl)amino-1-decyl-β-D-glucopyranoside (BADG) was synthesised and shown to be a high-affinity inhibitor of the renal Na +-D-glucose contransporter. From renal brush-border membranes a protein fraction was isolated, in which the concentration of Na +-dependent phlorizin binding sites per mg protein was enriched 7-fold. In labeling experiments with this protein fraction a polypeptide of M r ~ 79000 was identified as containing the D-glucose binding site of the renal Na +-D-glucose cotransporter. Affinity labeling D-Glucose analog D-Glucose binding site Na±D-glucose cotransporter Brush-border membrane Kidney