Facile Peptide Macrocyclization and Multifunctionalization via Cyclen Installation

Area of Science:

• Bioconjugation Chemistry
• Peptide Synthesis
• Lanthanide Probes

Background:

• Traditional cyclen-peptide bioconjugate synthesis is multi-step and complex.
• Individual preparation and purification of cyclic peptides and cyclen derivatives are required.
• A need exists for more efficient and versatile methods.

Purpose of the Study:

• To develop an efficient strategy for peptide cyclization and functionalization.
• To enable the creation of multifunctional cyclen-embedded cyclopeptides.
• To demonstrate the utility of this method for lanthanide probe development.

Main Methods:

• Three-component intermolecular crosslinking on solid-phase peptide synthesis.
• Incorporation of cyclen derivatives into cyclic peptides.
• Functionalization with lanthanide ions (Eu3+ and Gd3+).

Main Results:

• High conversion yield achieved in the synthesis process.
• Demonstrated successful preparation of cyclen-embedded cyclic arginylglycylaspartic acid (RGD) peptide.
• Developed a luminescent Eu3+ complex for optical imaging and a Gd3+-based agent for MRI.

Conclusions:

• The novel strategy offers an efficient route to cyclen-peptide bioconjugates.
• This method allows for the creation of multifunctional probes with tunable properties.
• The developed probes show promise for both in vitro and in vivo imaging applications.