Light-driven post-translational installation of reactive protein side chains.

Area of Science:

• Biochemistry
• Synthetic Biology
• Organic Chemistry

Background:

• Post-translational modifications (PTMs) expand protein structure and function.
• Current synthetic protein functionalization methods have limited functional group introduction.
• There is a need for versatile methods to create unnatural protein variants.

Purpose of the Study:

• To develop a visible-light-driven method for installing diverse side chains onto proteins.
• To enable site-selective protein modification with high efficiency and minimal damage.
• To expand the repertoire of functional groups and linkages accessible on proteins.

Main Methods:

• Visible-light-driven radical formation at dehydroalanine residues in proteins.
• In situ generation of boronic acid catechol ester derivatives for native linkages.
• In situ potentiation of pyridylsulfonyl derivatives for difluoromethylene labels.
• Chemoselective initiation in the presence of sensitive functional groups.

Main Results:

• Successful installation of over 50 unique side chains onto diverse protein scaffolds.
• Demonstrated formation of both native (C-C) and difluoromethylene (C-CF2) linkages.
• Achieved site-selective modification with good conversions and reduced protein damage.
• Showcased applications in studying enzyme selectivity and creating 'alkylator proteins'.

Conclusions:

• This visible-light-driven method significantly expands the scope of protein functionalization.
• The technique allows for the creation of novel protein functions and mimics natural PTMs.
• Provides a versatile platform for generating unnatural protein variants for various applications.