Azo-PROTAC: Novel Light-Controlled Small-Molecule Tool for Protein Knockdown.

Area of Science:

• Biochemistry
• Molecular Biology
• Chemical Biology

Background:

• Controlling endogenous protein levels is a significant challenge in biological research and therapeutics.
• Existing methods for protein knockdown often lack precise temporal or spatial control.

Purpose of the Study:

• To design and evaluate photoswitchable azobenzene-proteolysis targeting chimeras (Azo-PROTACs) for light-inducible and reversible protein degradation.
• To investigate the impact of different Azo-PROTAC configurations and linker lengths on protein knockdown efficiency.

Main Methods:

• Synthesis of azobenzene-containing proteolysis targeting chimeras (Azo-PROTACs) incorporating ligands for E3 ligases and target proteins.
• Assessment of light-induced protein degradation in intact cells using varying Azo-PROTAC designs.
• Comparative analysis of protein degradation efficacy based on Azo-PROTAC configuration and linker length.

Main Results:

• Azo-PROTACs demonstrated light-controlled protein knockdown in cells.
• The light-induced configuration change of azobenzene moieties enabled reversible switching of protein degradation activity.
• Optimized Azo-PROTACs effectively degraded BCR-ABL fusion and ABL proteins in K562 cells.

Conclusions:

• Azo-PROTACs offer a potent and reversible chemical knockdown strategy for targeted protein degradation.
• The facile cell uptake and reversible photoswitchability of Azo-PROTACs present a promising approach for precise control of protein levels.