Site-selective protein editing by backbone extension acyl rearrangements

Area of Science:

• Biochemistry
• Synthetic Biology
• Materials Science

Background:

• Protein and polypeptide heteropolymers with non-alpha backbone monomers are valuable for materials and therapeutics.
• Traditional genetic code expansion methods face limitations in biosynthesizing these complex structures in cells.

Purpose of the Study:

• To develop a next-generation approach for creating protein heteropolymers with non-alpha backbone monomers.
• To enable the post-translational editing of protein backbones within cells.

Main Methods:

• Utilizing orthogonal aminoacyl-tRNA synthetase enzymes that accept alpha-hydroxy acid monomers with masked nucleophiles.
• Introducing these modified monomers into proteins during in vivo translation.
• Employing a backbone extension acyl rearrangement (BEAR) reaction triggered by nucleophile unmasking to edit the protein backbone.

Main Results:

• Successfully generated protein heteropolymers containing beta-backbone, gamma-backbone, and delta-backbone monomers.
• Demonstrated a general strategy for installing extended backbones into genetically encoded proteins and peptides.
• Achieved post-translational modification of protein backbones within living cells.

Conclusions:

• The BEAR reaction provides a versatile strategy for synthesizing novel protein materials with extended backbones.
• This approach overcomes limitations of traditional genetic code expansion for creating non-alpha backbone heteropolymers.
• The method holds potential for developing advanced biomaterials and therapeutics.