A Genetically Encoded Picolyl Azide for Improved Live Cell Copper Click Labeling.

Area of Science:

• Biochemistry
• Chemical Biology
• Molecular Biology

Background:

• Bioorthogonal chemistry enables selective reactions within biological systems.
• Copper-catalyzed azide-alkyne cycloaddition (CuAAC) is a key bioorthogonal reaction.
• Amber suppression facilitates site-specific incorporation of noncanonical amino acids (ncAAs) with chemical handles into proteins.

Purpose of the Study:

• To explore the direct incorporation of copper-chelating azides into proteins.
• To develop a novel ncAA for enhanced CuAAC efficiency.
• To assess the utility of PazK in mammalian cell protein labeling.

Main Methods:

• Preparation of paz-lysine (PazK) containing a picolyl azide motif.
• Site-specific incorporation of PazK into proteins using amber suppression in mammalian cells.
• Evaluation of CuAAC reactivity of PazK-labeled proteins with alkyne reagents.

Main Results:

• PazK is efficiently incorporated into proteins in mammalian cells via amber suppression.
• PazK-labeled proteins exhibit enhanced reactivity in CuAAC reactions.
• This study demonstrates the feasibility of directly incorporating copper-chelating azides into proteins.

Conclusions:

• PazK is a valuable tool for advancing bioorthogonal chemistry in proteins.
• The direct incorporation of PazK improves CuAAC reaction efficiency.
• This method offers new possibilities for protein modification and functionalization.