N-to-C sequential ligation using peptidyl N,N-bis(2-mercaptoethyl)amide building blocks

Area of Science:

• Biochemistry
• Organic Chemistry
• Synthetic Biology

Background:

• Chemical ligation is crucial for synthesizing large proteins.
• Native chemical ligation (NCL) has limitations in certain reaction conditions.
• Developing robust ligation strategies is essential for advancing protein synthesis.

Purpose of the Study:

• To develop a novel N- to C-terminus sequential chemical ligation approach for protein synthesis.
• To investigate the stability of N,N-bis(2-mercaptoethyl)amide (BMEA) under ligation conditions.
• To identify effective thiol additives for BMEA-mediated ligation.

Main Methods:

• Developed a sequential chemical ligation strategy.
• Utilized N,N-bis(2-mercaptoethyl)amide (BMEA) for peptide bond formation.
• Employed a new thiol additive in the BMEA-mediated ligation reaction.
• Synthesized a medium-sized peptide and ubiquitin to demonstrate the method's utility.

Main Results:

• Established a novel N- to C-terminus sequential chemical ligation approach.
• Demonstrated the stability of the BMEA intermediate under conventional native chemical ligation conditions.
• Identified a new, effective thiol additive for the BMEA ligation reaction.
• Successfully synthesized a medium-sized peptide and ubiquitin, validating the new method.

Conclusions:

• The novel sequential chemical ligation approach offers a robust alternative for protein synthesis.
• The stability of the BMEA intermediate and the efficacy of the new thiol additive are key advantages.
• This method expands the toolkit for synthesizing complex peptides and proteins.