8P0Z

AP01-S2.3 - a variant of a redesigned transferrin receptor apical domain

Summary for 8P0Z

• Entry DOI: 10.2210/pdb8p0z/pdb
• Descriptor: Transferrin receptor protein 1, serum form, SODIUM ION, BORIC ACID, ... (4 entities in total)
• Functional Keywords: receptor domain, transferrin, cytosolic protein
• Biological source: Homo sapiens (human); More
• Total number of polymer chains: 1
• Total formula weight: 18288.42

Authors

Oberdorfer, G.,Grill, B.,Bjelic, S.,Stoll, D. (deposition date: 2023-05-11, release date: 2023-09-27, Last modification date: 2024-11-06)

Primary citation

Sjostrom, D.J.,Grill, B.,Ambrosetti, E.,Veetil, A.A.,Mohlin, C.,Teixeira, A.I.,Oberdofer, G.,Bjelic, S.
Affinity Maturated Transferrin Receptor Apical Domain Blocks Machupo Virus Glycoprotein Binding.
J.Mol.Biol., 435:168262-168262, 2023

PubMed Abstract: Transferrin receptor 1 (TfR) delivers iron across cellular membranes by shuttling the ion carrier protein transferrin. This ability to deliver large protein ligands inside cells is taken advantage of by pathogens to infiltrate human cells. Notably, the receptor's outermost ectodomain, the apical domain, is used as a point of attachment for several viruses including hemorrhagic arenaviruses. To better understand interactions with the receptor it would be advantageous to probe sequence determinants in the apical domain with viral spike proteins. Here, we carried out affinity maturation of our computationally designed apical domain from human TfR to identify underlying driving forces that lead to better binding. The improved variants were confirmed by in vitro surface plasmon resonance measurements with dissociation constants obtained in the lower nanomolar range. It was found that the strong binding affinities for the optimized variants matched the strength of interactions with the native receptor. The structure of the best variant was determined experimentally indicating that the conformational change in the hairpin binding motif at the protein-protein interface plays a crucial role. The experimental methodology can be straightforwardly applied to other arenavirus or pathogens that use the apical domain. It can further be useful to probe host-virus compatibility or therapeutic strategies based on the transferrin receptor decoys.

PubMed: 37678707
DOI: 10.1016/j.jmb.2023.168262

Experimental method

X-RAY DIFFRACTION (1.88 Å)