1. Signaling Pathways

PROTAC (蛋白降解靶向嵌合体)

PROTAC 全称为proteolysis-targeting chimeras (蛋白降解靶向嵌合分子),是一种杂合双功能小分子化合物,结构中含有两种不同配体,一个是泛素连接酶 E3 配体,另一个是与细胞中目标靶蛋白结合的配体,两个配体之间通过 linker 相连,从而形成 “ 三体 ” 聚合物——靶蛋白配体-Linker-E3 配体。PROTACs通过将目标靶蛋白和细胞内的 E3 泛素连接酶的距离拉近,利用“泛素-蛋白酶体”途径特异性的降解靶蛋白。PROTACs能够改善“不可成药”靶点的成药性。


Overview of PROTAC:

PROTACs or Proteolysis Targeting Chimeric Molecules are heterobifunctional nanomolecules that theoretically target any protein for ubiquitination and degradation. In terms of the structure, PROTACs consist of one moiety which is recognized by the E3 ligase. This moiety is then chemically and covalently linked to a small molecule or a protein that recognizes the target protein. The trimeric complex formation leads to the transfer of ubiquitins to the target protein.

By removing target proteins directly rather than merely blocking them, PROTACs can provide multiple advantages over small molecule inhibitors, which can require high systemic exposure to achieve sufficient inhibition, often resulting in toxic side effects and eventual drug resistance. PROTAC molecules possess good tissue distribution and the ability to target intracellular proteins, thus can be directly applied to cells or injected into animals without the use of vectors.

Targeted protein degradation using the PROTAC technology is emerging as a novel therapeutic method to address diseases, such as cancer, driven by the aberrant expression of a disease-causing protein. In addition to the use of PROTACs for the treatment of human disease, these molecules provide a chemical genetic approach to “knock down” proteins to study their function. Currently, there are several small molecule inhibitors that have been found to show good biological activity by specifically targeting BET, estrogen receptor (ER), androgen receptor, etc.

LYTAC, AUTAC and ATTEC are PROTAC degraders specifically targeting membrane proteins via lysosomal pathway. SNIPER and molecular glue are special PROTACs, while SNIPER consists of ligand for RING E3 ligase family and molecular glue comprises a short or almost no linker.



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