Tomala Marcin D, Magiera-Mularz Katarzyna, Kubica Katarzyna, Krzanik Sylwia, Zieba Bartosz, Musielak Bogdan, Pustula Marcin, Popowicz Grzegorz M, Sattler Michael, Dubin Grzegorz, Skalniak Lukasz, Holak Tad A
Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387, Krakow, Poland.
Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387, Krakow, Poland.
Eur J Med Chem. 2018 Apr 25;150:261-267. doi: 10.1016/j.ejmech.2018.03.009. Epub 2018 Mar 5.
USP2a is a deubiquitinating protease that rescues its target proteins from destruction by the proteasome by reversing the process of protein ubiquitination. USP2a shows oncogenic properties in vivo and has been found to be a specific activator of cyclin D1. Many types of cancers are addicted to cyclin D1 expression. Targeting USP2a is a promising strategy for cancer therapy but little progress has been made in the field of inhibition of USP2a. Using NMR-based fragment screening and biophysical binding assays, we have discovered small molecules that bind to USP2a. Iterations of fragment combination and structure-driven design identified two 5-(2-thienyl)-3-isoxazoles as the inhibitors of the USP2a-ubiquitin protein-protein interaction. The affinity of these molecules for the catalytic domain of USP2a parallels their ability to interfere with USP2a binding to ubiquitin in vitro. Altogether, our results establish the 5-(2-thienyl)-3-isoxazole pharmacophore as an attractive starting point for lead optimization.
USP2a是一种去泛素化蛋白酶，它通过逆转蛋白质泛素化过程，使靶蛋白免遭蛋白酶体的破坏。USP2a在体内表现出致癌特性，并且已被发现是细胞周期蛋白D1的特异性激活剂。许多类型的癌症都依赖于细胞周期蛋白D1的表达。靶向USP2a是一种很有前景的癌症治疗策略，但在USP2a抑制领域进展甚微。通过基于核磁共振的片段筛选和生物物理结合测定，我们发现了与USP2a结合的小分子。片段组合和结构驱动设计的反复操作确定了两种5-(2-噻吩基)-3-异恶唑作为USP2a-泛素蛋白-蛋白相互作用的抑制剂。这些分子对USP2a催化结构域的亲和力与其在体外干扰USP2a与泛素结合的能力相当。总之，我们的结果确立了5-(2-噻吩基)-3-异恶唑药效团作为先导化合物优化的一个有吸引力的起点。
