title: Nucleoside transport. Photoaffinity labelling of high-affinity nitrobenzylthioinosine binding sites in rat and guinea pig lung.
abstract: Binding of the potent nucleoside transport inhibitor [3H]nitrobenzylthioinosine to rat and guinea pig lung membranes was investigated. Reversible high-affinity binding was found in both species (apparent KD approximately 0.3nM). Binding was inhibited by nitrobenzylthioguanosine, adenosine and uridine. Dipyridamole was also an effective inhibitor of [3H]nitrobenzylthioinosine binding to guinea pig membranes. In contrast, rat membranes were relatively insensitive to dipyridamole. Exposure of site-bound [3H]nitrobenzylthioinosine to high intensity U.V. light resulted in the photoaffinity labelling of lung proteins with apparent molecular weights similar to that of the human erythrocyte nucleoside transporter (45,000-65,000).
mesh_terms: D000241:Adenosine / Q000494:pharmacology; D000345:Affinity Labels; D000818:Animals; D001665:Binding Sites; D001692:Biological Transport / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D004176:Dipyridamole / Q000494:pharmacology; D006168:Guinea Pigs; D007288:Inosine / Q000031:analogs & derivatives*; D007700:Kinetics; D008168:Lung / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D009705:Nucleosides / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013868:Thioinosine / Q000031:analogs & derivatives* / Q000378:metabolism; D014529:Uridine / Q000494:pharmacology
chemical_list: D000345:Affinity Labels; D009705:Nucleosides; D013868:Thioinosine; D007288:Inosine; D004176:Dipyridamole; C001789:4-nitrobenzylthioinosine; D000241:Adenosine; D014529:Uridine