High-affinity peptides developed against calprotectin and their application as synthetic ligands in diagnostic assays.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 37198182.
- Also identified by DOI 10.1038/s41467-023-38075-7 and PMC identifier 10192418.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Common inflammatory disorders such as ulcerative colitis and Crohn's disease are non-invasively diagnosed or monitored by the biomarker calprotectin. However, current quantitative tests for calprotectin are antibody-based and vary depending on the type of antibody and assay used. Additionally, the binding epitopes of applied antibodies are not characterized by structures and for most antibodies it is unclear if they detect calprotectin dimer, tetramer, or both. Herein, we develop calprotectin ligands based on peptides, that offer advantages such as homogenous chemical composition, heat-stability, site-directed immobilization, and chemical synthesis at high purity and at low cost. By screening a 100-billion peptide phage display library against calprotectin, we identified a high-affinity peptide (K<sub>d</sub> = 26 ± 3 nM) that binds to a large surface region (951 Å<sup>2</sup>) as shown by X-ray structure analysis. The peptide uniquely binds the calprotectin tetramer, which enabled robust and sensitive quantification of a defined species of calprotectin by ELISA and lateral flow assays in patient samples, and thus offers an ideal affinity reagent for next-generation inflammatory disease diagnostic assays.
Medical subject headings
- Crohn Disease
- Colitis, Ulcerative