Fluorescent P-Hydroxyphosphole for Peptide Labeling through P-N Bond Formation

Area of Science:

• Organic Chemistry
• Biochemistry
• Fluorescence Spectroscopy

Background:

• Peptide labeling is crucial for characterizing biomolecular interactions.
• Existing fluorophores may have limitations in size, spectral properties, or conjugation methods.

Purpose of the Study:

• To develop a novel class of compact, fluorescent probes for biomolecule labeling.
• To establish a versatile method for conjugating these probes to peptides.
• To demonstrate the utility of these probes in studying receptor-ligand interactions.

Main Methods:

• Synthesis of P-hydroxybinaphtylphosphole-oxide/-sulfide via dianion trapping and P-center modification.
• Peptide coupling using the BOP reagent in solution or on solid support.
• Fluorescence Resonance Energy Transfer (FRET) competition assays for ligand characterization.

Main Results:

• Successful synthesis of novel fluorescent P-hydroxyphospholes.
• Demonstrated efficient peptide labeling with these fluorophores, exemplified by JMV2959 (a GHS-R1a antagonist).
• Characterization of Growth Hormone Secretagogue Receptor (GHSR) ligands using FRET assays.

Conclusions:

• P-hydroxyphosphole-oxide/-sulfide represent a promising new class of compact fluorophores.
• The developed method allows versatile biomolecule labeling via phosphorus atom grafting.
• These fluorophores are valuable tools for characterizing biomolecular targets like GHSR.