title: Design, synthesis, and evaluation of 5'-S-aminoethyl-N(6)- azidobenzyl-5'-thioadenosine biotin conjugate: a bifunctional photoaffinity probe for the es nucleoside transporter.
abstract: A bifunctional biotinylated photoaffinity label for the nitrobenzylmercaptopurine riboside (NBMPR)-sensitive (es) nucleoside transporter (ENT1) has been synthesized and evaluated. This new probe,5'-S-aminoethyladenosine-N(6)-azidobenzyl-5'-thioadenosine biotin conjugate (SAEATA-14-biotin), exhibited high-affinity binding to the es transporter in K562 cells as determined by flow cytometry, with a K(i) of 2.69 nM in competition against 5-(SAENTA)-x8-fluorescein. It also exhibited covalent linking to the es transporter in BeWo cell membranes upon UV irradiation. This new bifunctional probe is a potential tool for determining the amino acid residues involved in ligand binding at the NBMPR-binding site of the ENT1 nucleoside transporter, as well as for the purification of the transporter.
authors.affiliation: Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Sciences Center, 847 Monroe Avenue, Memphis, TN 38163, USA.
authors.forename: James K
authors.initials: JK
authors.lastname: Addo
authors.forename: John K
authors.initials: JK
authors.lastname: Buolamwini
mesh_terms: D000241:Adenosine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry*; D001710:Biotin / Q000138:chemical synthesis / Q000737:chemistry*; D015195:Drug Design; D008024:Ligands; D015394:Molecular Structure; D033703:Nucleoside Transport Proteins / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D019920:Photoaffinity Labels / Q000737:chemistry* / Q000378:metabolism* / Q000493:pharmacokinetics; D013872:Thionucleosides / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D008024:Ligands; D033703:Nucleoside Transport Proteins; D019920:Photoaffinity Labels; D013872:Thionucleosides; C066257:5'-S-(2-aminoethyl)-N(6)-(4-nitrobenzyl)-5'-thioadenosine; D001710:Biotin; D000241:Adenosine