Structure-selective modification of aromatic side chains with dirhodium metallopeptide catalysts

Area of Science:

• Biochemistry
• Chemical Biology
• Organic Chemistry

Background:

• Selective modification of peptides is crucial for understanding protein structure and function.
• Existing methods often lack specificity, leading to complex product mixtures.
• Aromatic residues, like phenylalanine, are important but challenging to modify selectively.

Purpose of the Study:

• To develop a novel method for residue-selective chemical modification of peptides.
• To achieve selective modification of aromatic side chains within specific peptide structures.
• To enable the first selective chemical modification of phenylalanine residues in peptides.

Main Methods:

• Utilizing peptide molecular recognition to guide catalysis.
• Employing residue-selective dirhodium catalysis for targeted modification.
• Comparing the reactivity of the new method against nonselective dirhodium modification.

Main Results:

• Achieved modification of aromatic side chains selective for coil structures.
• Observed a rate enhancement greater than 10^3 compared to nonselective methods.
• Demonstrated the first instance of selective chemical modification of the phenylalanine residue.

Conclusions:

• The combination of molecular recognition and dirhodium catalysis offers high selectivity for peptide modification.
• This approach significantly enhances reaction rates, overcoming previous limitations.
• This work establishes a powerful new tool for site-specific peptide functionalization and analysis.