Delineating the role of cooperativity in the design of potent PROTACs for BTK
Delineating the role of cooperativity in the design of potent PROTACs for BTK
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DOI：
10.1073/pnas.1803662115
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发表时间：
2018-07-31
影响因子：
11.1
通讯作者：
Calabrese, Matthew F.
中科院分区：
文献类型：
--
作者：
Zorba, Adelajda;Chuong Nguyen;Calabrese, Matthew F.
蛋白水解靶向嵌合体(PROTAC)是一种异质双功能的小分子，它同时与靶蛋白和E3连接酶结合，从而导致靶蛋白的泛素化和随后的降解。它们提供了一个令人兴奋的机会，以一种独立于酶或信号活性的方式调节蛋白质。因此，它们最近已成为一种有吸引力的机制，用于探索以前“无法下药”的靶点。尽管有这种兴趣，但对于实现效力和选择性最关键的参数，根本问题仍然存在。在这里，我们使用一系列生化和细胞技术来研究有效地敲除Bruton酪氨酸激酶(BTK)的要求，BTK是一种对B细胞成熟至关重要的非受体酪氨酸激酶。研究了11个化合物PROTAC文库的成员与BTK和Cereblon(CRBN，E3连接酶组分)形成二元和三元络合物的能力。结果扩展到测量BTK-CRBN协同作用的影响以及BTK在体外和体内的降解。我们的数据表明，在这个化学系列中，通过调节PROTAC连接基的长度来缓解BTK和CRBN之间的空间冲突，可以在没有热力学协作性的情况下有效地降解BTK。
Proteolysis targeting chimeras (PROTACs) are heterobifunctional small molecules that simultaneously bind to a target protein and an E3 ligase, thereby leading to ubiquitination and subsequent degradation of the target. They present an exciting opportunity to modulate proteins in a manner independent of enzymatic or signaling activity. As such, they have recently emerged as an attractive mechanism to explore previously "undruggable" targets. Despite this interest, fundamental questions remain regarding the parameters most critical for achieving potency and selectivity. Here we employ a series of biochemical and cellular techniques to investigate requirements for efficient knockdown of Bruton's tyrosine kinase (BTK), a nonreceptor tyrosine kinase essential for B cell maturation. Members of an 11-compound PROTAC library were investigated for their ability to form binary and ternary complexes with BTK and cereblon (CRBN, an E3 ligase component). Results were extended to measure effects on BTK-CRBN cooperative interactions as well as in vitro and in vivo BTK degradation. Our data show that alleviation of steric clashes between BTK and CRBN by modulating PROTAC linker length within this chemical series allows potent BTK degradation in the absence of thermodynamic cooperativity.