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. 1983 Apr;80(8):2263–2266. doi: 10.1073/pnas.80.8.2263

Binding of apotransferrin to K562 cells: explanation of the transferrin cycle.

R D Klausner, G Ashwell, J van Renswoude, J B Harford, K R Bridges
PMCID: PMC393799  PMID: 6300904

Abstract

The binding of apotransferrin to the transferrin receptor on the surface of human leukemic K562 cells was found to be significantly less tight than that of the holoprotein, diferric transferrin. The finding that both ligands displayed linear Scatchard plots with similar receptor number (approximately equal to 150,000 per cell) and mutually inhibit each other's binding suggested that they bind to the same receptor. Both the dissociation and association rate of apotransferrin were markedly increased (28-fold and 15-fold, respectively) at pH 7.2 compared to pH 4.8. Using the values of these binding parameters, we propose a mechanism to account for the recycling of transferrin subsequent to internalization and residence within an acidic nonlysosomal organelle where iron is removed.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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