Dual native chemical ligation at lysine

Area of Science:

• Biochemistry
• Organic Chemistry
• Protein Chemistry

Background:

• Native chemical ligation (NCL) is a powerful tool for protein synthesis.
• Modifications on lysine residues, such as post-translational modifications, are crucial for protein function.
• Existing NCL methods have limitations in modifying specific amino acid side chains.

Purpose of the Study:

• To develop a new method for native chemical ligation that specifically targets lysine residues.
• To enable the synthesis of proteins with isopeptide bonds on lysine side chains.
• To facilitate the study of proteins with complex post-translational modifications.

Main Methods:

• Introduction of a thiol group on the gamma-carbon of lysine.
• Two-step consecutive native chemical ligation at both alpha- and epsilon-amines.
• Desulfurization to yield the final protein product.

Main Results:

• Achieved robust native chemical ligation mediated by the modified lysine residue.
• Successfully formed isopeptide bonds on the lysine side chain.
• Demonstrated the utility of the method for synthesizing modified proteins.

Conclusions:

• The developed method provides a versatile approach for protein synthesis.
• This technique is particularly useful for creating proteins with specific lysine modifications.
• The method expands the possibilities for studying protein structure and function.