Determination of the Dissociation Constant for Polyvalent Receptors Using ELISA: A Case of M13 Phages Displaying Troponin T-Specific Peptides

Sebastian J Machera; Joanna Niedziółka-Jönsson; Martin Jönsson-Niedziółka; Katarzyna Szot-Karpińska

doi:10.1021/acsomega.3c02551

Determination of the Dissociation Constant for Polyvalent Receptors Using ELISA: A Case of M13 Phages Displaying Troponin T-Specific Peptides

ACS Omega. 2023 Jul 12;8(29):26253-26262. doi: 10.1021/acsomega.3c02551. eCollection 2023 Jul 25.

Authors

Sebastian J Machera¹, Joanna Niedziółka-Jönsson¹, Martin Jönsson-Niedziółka¹, Katarzyna Szot-Karpińska¹

Affiliation

¹ Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, Warsaw 01-244, Poland.

Abstract

Phage-derived affinity peptides have become widespread thanks to their easy selection via phage display. Interactions between a target protein and its specific peptide are similar to those between antibodies and antigens. The strength of these non-covalent complexes may be described by the dissociation constant (K_d). In this paper, protein-specific peptides are exposed on the pIII protein present in the M13 bacteriophage virion with up to five copies. Therefore, one phage particle can bind from one to five ligands. Here, we discuss the dependences between phage-displayed peptides and their ligands in solution using a model system based on troponin T (TnT) binding phages. Moreover, a method of calculating K_d values from ELISA experiments was developed and is presented. The determined K_d values are in the picomolar range.