A Versatile Method for Site-Specific Chemical Installation of Aromatic Posttranslational Modification Analogs into...

Area of Science:

• Biochemistry
• Chemical Biology
• Proteomics

Background:

• Posttranslational modifications (PTMs) are crucial for protein regulation, with tyrosine (Tyr) PTMs impacting health and disease.
• Current limitations in mimicking and introducing aromatic PTMs hinder understanding of their roles.
• A need exists for tools to site-specifically install aromatic PTMs into proteins.

Purpose of the Study:

• To develop a facile method for site-specific chemical installation of aromatic PTMs into proteins.
• To enable the study of Tyr-PTMs, including nitration and phosphorylation analogs.
• To generate homogeneous libraries of modified proteins for discovery applications.

Main Methods:

• Utilized palladium-mediated S-C(sp2) bond formation under ambient conditions.
• Incorporated novel PTMs like Tyr-nitration and phosphorylation analogs into peptides and proteins.
• Applied the method to create modified Myc, Max, and alpha-synuclein (α-Syn) proteins.

Main Results:

• Demonstrated rapid, site-specific introduction of aromatic PTMs in minutes with good yields.
• Successfully prepared 10 site-specifically modified proteins, including nitrated and phosphorylated Myc and Max analogs.
• Generated a library of modified α-Syn, revealing insights into competing modifications' roles in aggregation.

Conclusions:

• The developed method allows rapid and selective transfer of aromatic PTMs into recombinant proteins.
• This approach facilitates the creation of homogeneous PTM libraries for biomarker and drug discovery.
• Enables mechanistic studies and a deeper understanding of Tyr-PTM roles in health and disease.