A general method for artificial metalloenzyme formation through strain-promoted azide-alkyne cycloaddition

Area of Science:

• Biochemistry
• Organic Chemistry
• Materials Science

Background:

• Artificial metalloenzymes (ArMs) combine protein scaffolds with metal cofactors for novel catalytic functions.
• Strain-promoted azide-alkyne cycloaddition (SPAAC) is a bioorthogonal click chemistry reaction.
• SPAAC offers a modular approach for constructing ArMs independent of native amino acid residues.

Purpose of the Study:

• To develop a versatile method for generating artificial metalloenzymes (ArMs) using SPAAC.
• To demonstrate the broad applicability of SPAAC in ArM construction with various scaffolds and metal complexes.
• To showcase the catalytic capabilities of SPAAC-generated ArMs.

Main Methods:

• Incorporation of p-azido-L-phenylalanine (Az) into scaffold proteins.
• Utilizing SPAAC for covalent linkage between Az-containing proteins and bicyclononyne-substituted metal complexes.
• Characterization of generated ArMs and their catalytic activity.

Main Results:

• Efficient formation of ArMs using SPAAC, even in complex biological environments.
• Demonstrated scope of the method across diverse scaffold and cofactor combinations.
• Generated dirhodium ArMs effectively catalyzed diazo compound decomposition, Si-H insertion, and olefin insertion reactions.

Conclusions:

• SPAAC provides a robust and versatile platform for artificial metalloenzyme synthesis.
• This method decouples ArM formation from the scaffold's native function, enabling broader applications.
• SPAAC-generated ArMs exhibit significant catalytic activity, paving the way for new inorganic-protein materials.