Selection of specific inhibitor peptides in enzyme-linked immunosorbent assay (ELISA) of cardiac troponin I using immuno-dominant epitopes as competitor

J Immunoassay Immunochem. 2017;38(1):72-81. doi: 10.1080/15321819.2016.1216444. Epub 2016 Aug 11.

Abstract

Human cardiac troponin I (cTni) is the gold marker for early diagnosis of myocardial infarction. In this regard, four immune-dominant epitopes of cTni were predicted and their 3D structures were determined. Thereafter, the competitive performance of the peptides was monitored with the developed polyclonal antibody-based indirect competitive ELISA; a half-maximal inhibitory concentration (IC50) of 0.49 (µg/mL) and detection limit of 0.037 (µg/mL) were achieved for recombinant cTni. The competitive ELISA determined sensitivity levels of 0.306, 0.141, 0.960, and 0.155 (µg/mL), respectively, for each peptide as competitor. We indicated that two of the selected epitopes have significant sensitivity scales and inhibition ability.

Keywords: 3D molecular structure; cardiac troponin I; enzyme-linked immunosorbent assay; immunodominant epitopes; molecular dynamics; polyclonal antibody.

MeSH terms

  • Binding, Competitive / immunology*
  • Dose-Response Relationship, Drug
  • Enzyme-Linked Immunosorbent Assay / methods*
  • Humans
  • Immunodominant Epitopes / chemistry*
  • Immunodominant Epitopes / immunology*
  • Immunosorbents / chemistry*
  • Molecular Dynamics Simulation
  • Myocardial Infarction / diagnosis
  • Myocardial Infarction / immunology
  • Peptides / chemistry
  • Peptides / immunology*
  • Troponin I / analysis*
  • Troponin I / chemistry
  • Troponin I / immunology*

Substances

  • Immunodominant Epitopes
  • Immunosorbents
  • Peptides
  • Troponin I