Nucleoside transport in human and sheep erythrocytes. Evidence that nitrobenzylthioinosine binds specifically to functional nucleoside-transport sites
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چکیده
منابع مشابه
Species differences in nucleoside transport. A study of uridine transport and nitrobenzylthioinosine binding by mammalian erythrocytes.
A kinetic study of the inward transport of uridine in erythrocytes of rabbit, human, mouse, rat and guinea-pig demonstrated that the apparent Km of this process was similar (about 0.2mM) in these cell types, but Vmax. values differed markedly. In this array of cell types, Vmax. values were proportional to the number of transport-inhibitory, high-affinity binding sites present per cell of each t...
متن کاملCharacterization of nitrobenzylthioinosine binding to nucleoside transport sites selective for adenosine in rat brain.
Nucleoside transport sites in rat brain membrane preparations were labeled with [3H]nitrobenzylthioinosine ([3H] NBI), a potent inhibitor of nucleoside transport systems. The membranes contained a single class of very high affinity binding sites with KD and Bmax values of 0.06 nM and 147 fmol/mg of protein, respectively. The displacement of [3H]NBI binding by various nucleosides, adenosine rece...
متن کاملExtraction and partial purification of the nucleoside-transport system from human erythrocytes based on the assay of nitrobenzylthioinosine-binding activity.
Nitrobenzylthioinosine, a potent nucleoside-transport inhibitor, binds to high-affinity sites on the human erythrocyte membrane. This binding is a specific interaction with functional nucleoside-transport sites. The protein(s) responsible for high-affinity nitrobenzylthioinosine binding was purified 13-fold by treatment of haemoglobin-free 'ghosts' with EDTA (pH 11.2) to remove extrinsic protei...
متن کاملExpression of high levels of nitrobenzylthioinosine-sensitive nucleoside transport in cultured human choriocarcinoma (BeWo) cells.
We have examined binding of [3H]nitrobenzylthioinosine (NBMPR) and influx of [3H]thymidine in adherent cultures of human choriocarcinoma (BeWo) cells and, for comparison, cervical-carcinoma (HeLa) cells. Specific association of NBMPR with BeWo cells at 22 degrees C required 1.5 h to reach an equilibrium between free and bound ligand, whereas association with HeLa cells required 20-30 min. Scatc...
متن کاملMammalian nitrobenzylthioinosine-sensitive nucleoside transport proteins. Immunological evidence that transporters differing in size and inhibitor specificity share sequence homology.
Polyclonal antibodies were raised against the nitrobenzylthioinosine (NBMPR)-sensitive nucleoside transporter of human erythrocyte membranes. On Western blots of these membranes they labeled the broad "band 4.5" region (average apparent M(r) 55,000), which contains both the nucleoside and glucose transport proteins. However, they did not recognize the glucose transporter when this was prepared ...
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ژورنال
عنوان ژورنال: Biochemical Journal
سال: 1980
ISSN: 0306-3283
DOI: 10.1042/bj1900377