Potential application of proteolysis targeting chimera (PROTAC) modification technology in natural products for their targeted protein degradation

There are numerous evaluations of natural products, of which majority are food bioactives, performed up to date for their various health beneficial activities via targeting specific proteins. However, the direct identification of a targeted protein remains unexplored for natural occurring compounds. Proteolysis targeting chimera (PROTAC) is a type of bifunctional chimeric molecules that can directly degrade the binding proteins targeted by bioactive molecules in an ubiquitin-proteasome pathway. As the agents in protein degradation dependent on ubiquitin ligase, the bifunctional molecule connects the target protein ligand and E3 ligase ligand together via an appropriate linker. It is highly selective and efficient to induce the ubiquitin-mediated degradation of targeted binding proteins. Therefore, it has been demonstrated that the PROTAC technology has broad application in the modulation of the target protein level. In this review, we outlined the advances in PROTAC combined molecule compounds, summarized its quantitative structure-activity relationship, and finally reviewed the methods applied in identifying the target proteins of natural products. We hope it will provide an insightful application of PROTAC techniques in the target protein identification of natural products including food bioactive molecules.