Chemoselective and site-selective peptide and native protein modification enabled by aldehyde auto-oxidation

Area of Science:

• Biochemistry
• Chemical Biology
• Proteomics

Background:

• Proteins contain various nucleophilic residues, including α-amines and ε-amines (lysine side chains).
• Site-specific modification of proteins is crucial for understanding protein function and developing targeted therapeutics.
• Existing methods often lack the selectivity to modify a single ε-amine in the presence of other reactive groups.

Purpose of the Study:

• To develop a chemoselective and site-selective method for formylating ε-amines in native proteins.
• To enable the labeling of a single ε-amine within a complex protein environment.
• To extend the methodology for site-selective acylation.

Main Methods:

• Utilizing aldehyde auto-oxidation re-routing for controlled formate generation.
• Employing reversible N-terminus protection strategies.
• Developing conditions for selective ε-amine formylation in the presence of α-amines and other nucleophiles.

Main Results:

• Achieved chemoselective and site-selective formylation of ε-amine in native proteins.
• Demonstrated the ability to label a single ε-amine among multiple copies and other reactive residues.
• Successfully extended the method to achieve site-selective acylation.

Conclusions:

• The developed formylation strategy offers unprecedented selectivity for modifying lysine side chains.
• This method provides a powerful tool for site-specific protein labeling and functional studies.
• The methodology has potential applications in chemical biology, proteomics, and drug development.