Photoaffinity labeling of the human erythrocyte monosaccharide transporter with an aryl azide derivative of D-glucose.

M F Shanahan,B E Wadzinski,J M Lowndes,A E Ruoho

doi:10.1016/s0021-9258(17)39116-0

Abstract

A photoreactive, radioiodinated derivative of glucose, N-(4-iodoazidosalicyl)-6-amido-6-deoxyglucopyranose (IASA-glc), has been synthesized and used as a photoaffinity label for the human erythrocyte monosaccharide transporter. Photoinactivation and photoinsertion are both light-dependent and result in a marked decrease in the absorption spectra of the compound. When [125I]IASA-glc was photolyzed with erythrocyte ghost membranes, photoinsertion of radiolabel was observed in three major regions, spectrin, band 3, and a protein of 58,000 daltons located in the zone 4.5 region. Of the three regions which were photolabeled, only labeling of polypeptides in the zone 4.5 region was partially blocked by D-glucose. In the non-iodinated form, N-(4-azidosalicyl)-6-amido-6-deoxy-glucopyranose inhibited the labeling of the transporter by [125I]IASA-glc more effectively than D-glucose. The ability to synthesize this [125I]containing photoprobe for the monosaccharide transporter at carrier-free levels offers several new advantages for investigating the structure of this transport protein in the erythrocyte.

Highlights

From the Departments of $Physiology, YPharmacology, and IIPhysiologicalChemistry, University of Wisconsin Medical School, Madison, Wisconsin 53706 number of limitations
In the present studywe describe a simple method for the synthesis of a phenyl azidederivative of D-glucose, N-(4-azidosalicyl)-6amido-6-deoxyglucopyranose(ASA-glc') and its carrier-free radioiodinated derivative ['251]IASA-glc
A photoreactive, radioiodinated derivative of glucose, N-(4-iodoazidosalicyl)-6-amido-6-deoxyglucopyranose (IASA-glc), has been synthesized and used Materiak-Na'251 was from New England Nuclear

Summary

Introduction

From the Departments of $Physiology, YPharmacology, and IIPhysiologicalChemistry, University of Wisconsin Medical School, Madison, Wisconsin 53706 number of limitations. In the present studywe describe a simple method for the synthesis of a phenyl azidederivative of D-glucose, N-(4-azidosalicyl)-6amido-6-deoxyglucopyranose(ASA-glc') and its carrier-free radioiodinated derivative ['251]IASA-glc. Theresultspresented in this report show that ['251]IASA-gl~ cbane used for specific covalent labeling of the human erythrocytemonosaccharide transporter.

Results

Conclusion