Nucleoside transport in human erythrocytes. Nitrobenzylthioinosine binding and uridine transport activities have similar radiation target sizes.
Intact human erythrocytes were irradiated in the frozen state with a high-energy electron beam. Nitrobenzylthioinosine-sensitive uridine influx, equilibrium exchange uridine influx and high-affinity nitrobenzylthioinosine binding were inactivated as a simple exponential function of the radiation dose, indicating an in situ target size of 122 000. The results suggest that the nitrobenzylthioinosine-binding site(s) and the permeation site(s) of the transporter are present on the same transporter element.
D001692:Biological Transport; D004307:Dose-Response Relationship, Radiation; D004910:Erythrocyte Membrane / Q000378:metabolism* / Q000528:radiation effects; D005615:Freezing; D006801:Humans; D007288:Inosine / Q000031:analogs & derivatives*; D007700:Kinetics; D013868:Thioinosine / Q000031:analogs & derivatives* / Q000097:blood; D014529:Uridine / Q000097:blood*
D013868:Thioinosine; D007288:Inosine; C001789:4-nitrobenzylthioinosine; D014529:Uridine