An Alkyne-functionalized Arginine for Solid-Phase Synthesis Enabling "Bioorthogonal" Peptide Conjugation

Area of Science:

• Organic Chemistry
• Biochemistry
• Peptide Chemistry

Background:

• Amino-functionalized Nω-carbamoylated arginines serve as arginine surrogates for peptide labeling.
• Existing methods face limitations with peptides containing lysine or cysteine.

Purpose of the Study:

• To synthesize a novel alkyne-functionalized Nω-carbamoylated arginine building block.
• To demonstrate its compatibility with Fmoc-strategy solid-phase peptide synthesis.
• To enable bioorthogonal peptide labeling via click chemistry.

Main Methods:

• Synthesis of an alkyne-functionalized Nω-carbamoylated arginine.
• Incorporation into linear and cyclic peptides using Fmoc-strategy solid-phase peptide synthesis.
• Conjugation to azido-functionalized fluorescent dyes via click chemistry.

Main Results:

• Successful synthesis of the alkynylated arginine building block.
• Demonstrated incorporation into various peptide structures.
• Achieved efficient peptide conjugation using click chemistry.
• Showcased bioorthogonal labeling in the presence of lysine.

Conclusions:

• The developed alkyne-functionalized arginine is a versatile tool for peptide labeling.
• This method overcomes limitations of previous approaches, allowing labeling in complex peptide sequences.
• Enables site-specific modification and conjugation for various biochemical applications.