Affinity Maturated Transferrin Receptor Apical Domain Blocks Machupo Virus Glycoprotein Binding.

Autor: Sjöström DJ; Department of Chemistry and Biomedical Sciences, Linnaeus University, Kalmar, Sweden., Grill B; Department of Biochemistry, Graz University of Technology, Graz, Austria., Ambrosetti E; Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Sweden., Veetil AA; Department of Chemistry and Biomedical Sciences, Linnaeus University, Kalmar, Sweden., Mohlin C; Department of Chemistry and Biomedical Sciences, Linnaeus University, Kalmar, Sweden., Teixeira AI; Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Sweden., Oberdofer G; Department of Biochemistry, Graz University of Technology, Graz, Austria., Bjelic S; Department of Chemistry and Biomedical Sciences, Linnaeus University, Kalmar, Sweden. Electronic address: Sinisa.Bjelic@lnu.se.
Jazyk: angličtina
Zdroj: Journal of molecular biology [J Mol Biol] 2023 Oct 15; Vol. 435 (20), pp. 168262. Date of Electronic Publication: 2023 Sep 09.
DOI: 10.1016/j.jmb.2023.168262
Abstrakt: 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.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)
Databáze: MEDLINE
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