Utilizing reversible copper(II) peptide coordination in a sequence-selective luminescent receptor.

Area of Science:

• Chemical Biology
• Supramolecular Chemistry
• Biophysical Chemistry

Background:

• Limited use of metal ion coordination in designing selective peptide receptors.
• Amino acids and peptides exhibit known coordination abilities with metal ions.

Purpose of the Study:

• To develop a rational design strategy for sequence-selective peptide receptors.
• To create a luminescent sensor for peptide binding based on metal ion coordination.

Main Methods:

• Combining a copper(II) nitrilotriacetato (NTA) complex with a benzocrown ether.
• Utilizing fluorescence emission to detect binding events.
• Employing isothermal titration calorimetry to confirm binding constants.

Main Results:

• The designed receptor showed micromolar affinities and selectivities for glycine- and histidine-containing peptides.
• Binding modes mimicked copper(II) ion coordination to peptides.
• Luminescent signal correlated with intramolecular ammonium ion-benzocrown ether interaction upon peptide binding.

Conclusions:

• A truncated copper(II) coordination sphere combined with a luminescent benzocrown ether enables rational design of peptide receptors.
• This approach offers enhanced selectivity for specific peptide sequences.
• The system provides a sensitive luminescent readout for peptide recognition events.