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 (Kd). In this paper, protein-specific peptides are exposed on the pIII protein present in the M13 bacteriophage virion with up to 5 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 Kd values from ELISA experiments was developed and presented. Determined Kd values are in the picomolar range.
Supplementary materials
Title
Full mathematical model of calculation of Kd via indirect ELISA for non-monovalent TnT-specific phage particles
Description
an extended version of the mathematical model of interactions between ligand (TnT) and its specific peptide-displaying M13 bacteriophages (part I). In addition, theoretical aspects of the method of calculating dissociation constant from ELISA experiments were discussed (part II). All equations and assumptions are described in detail.
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