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Avidity observed between a bivalent inhibitor and an enzyme monomer with a single active site
Although myriad protein–protein interactions in nature use polyvalent binding, in which multiple ligands on one entity bind to multiple receptors on another, to date an affinity advantage of polyvalent binding has been demonstrated experimentally only in cases where the target receptor molecules are...
Autores principales: | , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Public Library of Science
2021
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8631645/ https://www.ncbi.nlm.nih.gov/pubmed/34847142 http://dx.doi.org/10.1371/journal.pone.0249616 |
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author | Lacham-Hartman, Shiran Shmidov, Yulia Radisky, Evette S. Bitton, Ronit Lukatsky, David B. Papo, Niv |
author_facet | Lacham-Hartman, Shiran Shmidov, Yulia Radisky, Evette S. Bitton, Ronit Lukatsky, David B. Papo, Niv |
author_sort | Lacham-Hartman, Shiran |
collection | PubMed |
description | Although myriad protein–protein interactions in nature use polyvalent binding, in which multiple ligands on one entity bind to multiple receptors on another, to date an affinity advantage of polyvalent binding has been demonstrated experimentally only in cases where the target receptor molecules are clustered prior to complex formation. Here, we demonstrate cooperativity in binding affinity (i.e., avidity) for a protein complex in which an engineered dimer of the amyloid precursor protein inhibitor (APPI), possessing two fully functional inhibitory loops, interacts with mesotrypsin, a soluble monomeric protein that does not self-associate or cluster spontaneously. We found that each inhibitory loop of the purified APPI homodimer was over three-fold more potent than the corresponding loop in the monovalent APPI inhibitor. This observation is consistent with a suggested mechanism whereby the two APPI loops in the homodimer simultaneously and reversibly bind two corresponding mesotrypsin monomers to mediate mesotrypsin dimerization. We propose a simple model for such dimerization that quantitatively explains the observed cooperativity in binding affinity. Binding cooperativity in this system reveals that the valency of ligands may affect avidity in protein–protein interactions including those of targets that are not surface-anchored and do not self-associate spontaneously. In this scenario, avidity may be explained by the enhanced concentration of ligand binding sites in proximity to the monomeric target, which may favor rebinding of the multiple ligand binding sites with the receptor molecules upon dissociation of the protein complex. |
format | Online Article Text |
id | pubmed-8631645 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-86316452021-12-01 Avidity observed between a bivalent inhibitor and an enzyme monomer with a single active site Lacham-Hartman, Shiran Shmidov, Yulia Radisky, Evette S. Bitton, Ronit Lukatsky, David B. Papo, Niv PLoS One Research Article Although myriad protein–protein interactions in nature use polyvalent binding, in which multiple ligands on one entity bind to multiple receptors on another, to date an affinity advantage of polyvalent binding has been demonstrated experimentally only in cases where the target receptor molecules are clustered prior to complex formation. Here, we demonstrate cooperativity in binding affinity (i.e., avidity) for a protein complex in which an engineered dimer of the amyloid precursor protein inhibitor (APPI), possessing two fully functional inhibitory loops, interacts with mesotrypsin, a soluble monomeric protein that does not self-associate or cluster spontaneously. We found that each inhibitory loop of the purified APPI homodimer was over three-fold more potent than the corresponding loop in the monovalent APPI inhibitor. This observation is consistent with a suggested mechanism whereby the two APPI loops in the homodimer simultaneously and reversibly bind two corresponding mesotrypsin monomers to mediate mesotrypsin dimerization. We propose a simple model for such dimerization that quantitatively explains the observed cooperativity in binding affinity. Binding cooperativity in this system reveals that the valency of ligands may affect avidity in protein–protein interactions including those of targets that are not surface-anchored and do not self-associate spontaneously. In this scenario, avidity may be explained by the enhanced concentration of ligand binding sites in proximity to the monomeric target, which may favor rebinding of the multiple ligand binding sites with the receptor molecules upon dissociation of the protein complex. Public Library of Science 2021-11-30 /pmc/articles/PMC8631645/ /pubmed/34847142 http://dx.doi.org/10.1371/journal.pone.0249616 Text en © 2021 Lacham-Hartman et al https://creativecommons.org/licenses/by/4.0/This is an open access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
spellingShingle | Research Article Lacham-Hartman, Shiran Shmidov, Yulia Radisky, Evette S. Bitton, Ronit Lukatsky, David B. Papo, Niv Avidity observed between a bivalent inhibitor and an enzyme monomer with a single active site |
title | Avidity observed between a bivalent inhibitor and an enzyme monomer with a single active site |
title_full | Avidity observed between a bivalent inhibitor and an enzyme monomer with a single active site |
title_fullStr | Avidity observed between a bivalent inhibitor and an enzyme monomer with a single active site |
title_full_unstemmed | Avidity observed between a bivalent inhibitor and an enzyme monomer with a single active site |
title_short | Avidity observed between a bivalent inhibitor and an enzyme monomer with a single active site |
title_sort | avidity observed between a bivalent inhibitor and an enzyme monomer with a single active site |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8631645/ https://www.ncbi.nlm.nih.gov/pubmed/34847142 http://dx.doi.org/10.1371/journal.pone.0249616 |
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