Rapid and Highly Selective Fluorescent Labeling of Peptides via a Thia-Diels-Alder Cycloaddition: Application to Apelin.
Maujean. Timothé T; Wagner. Patrick P; Valencia. Christel C; Riché. Stéphanie S; Iturrioz. Xavier X; Villa. Pascal P; Girard. Nicolas N; Karpenko. Julie J; Gulea. Mihaela M; Bonnet. Dominique D
Key Findings
- A catalyst‑free thia‑Diels‑Alder reaction can label fully deprotected phosphonodithioester‑peptides in water/alcohol at 37 °C within an hour.
- The method works with different fluorophores (fluorescein, rhodamine B, squaraine) and produces a fluorescent apelin‑13 ligand with very high affinity (0.17 ± 0.03 nM) for its receptor.
- The labeled ligand enables fast, high‑throughput FRET‑based screening and live‑cell imaging of the apelin receptor without washing steps.
Practical Outcomes
- For biohackers or self‑experimenters, this study doesn’t provide a new supplement, dosage, or health protocol. It’s a laboratory technique useful for researchers developing drug‑screening assays or imaging tools, not a direct tool for personal health optimization.
Summary
Scientists created a new, simple chemical reaction that sticks bright fluorescent tags onto tiny protein pieces (peptides) without needing harsh chemicals or catalysts. They showed it works quickly at body‑like temperature and used it to label a peptide called apelin‑13, which then lights up cells that have the apelin receptor.
Abstract
Herein, we describe a catalyst-free thia-Diels-Alder cycloaddition for the chemoselective labeling of fully deprotected phosphonodithioester-peptides in solution with fluorophores functionalized with an exocyclic diene. The reaction was optimized on the model tripeptide <b>1</b> containing a lysine residue, which enabled its rapid and straightforward labeling with three different fluorophores (fluorescein, lissamine rhodamine B, and squaraine) in very mild conditions (H<sub>2</sub>O/<i>i</i>PrOH, 37 °C, 1 h). The reaction was then successfully applied to the chemoselective labeling of fully deprotected apelin-13 with squaraine dye. The resulting fluorescent ligand <b>18</b> exhibited a high affinity (0.17 ± 0.03 nM) for apelinR. It enabled the development of time-resolved FRET-based competition assays for high-throughput screening and drug discovery. Thanks to its fluorogenic properties, ligand <b>18</b> was also successfully involved in the live-cell optical imaging of apelinR in no-wash conditions.
Study Information
pubmed
2022
2022-12-19T00:00:00.000Z
10.1021/acs.bioconjchem.2c00500
3
35