Login / Signup

Rapid and Highly Selective Fluorescent Labeling of Peptides via a Thia-Diels-Alder Cycloaddition: Application to Apelin.

Timothé MaujeanPatrick WagnerChristel ValenciaStéphanie RichéXavier IturriozPascal VillaNicolas GirardIuliia A KarpenkoMihaela GuleaDominique Bonnet
Published in: Bioconjugate chemistry (2022)
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 1 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 2 O/ 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 18 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 18 was also successfully involved in the live-cell optical imaging of apelinR in no-wash conditions.
Keyphrases
  • drug discovery
  • living cells
  • quantum dots
  • fluorescent probe
  • high resolution
  • amino acid
  • single molecule
  • high throughput
  • label free
  • metal organic framework
  • gold nanoparticles
  • molecularly imprinted
  • solid state