SMARCA2 is a critical catalytic subunit of the switch/sucrose non-fermenting (SWI/SNF) chromatin remodeling complexes. Dysregulation of SMARCA2 is associated with several diseases, including some cancers. SMARCA2 is multi-domain protein containing a bromodomain (BRD) that specifically recognizes acetylated lysine residues in histone tails, thus playing an important role in chromatin remodeling. Many potent and specific inhibitors targeting other BRDs have recently been discovered and have been widely used for cancer treatments and biological research. However, hit discovery targeting SMARCA2-BRD is particularly lacking. To date, there is a paucity of reported high-throughput screening (HTS) assays targeting the SMARCA2-BRD interface. In this study, we developed an AlphaScreen HTS system for the discovery of SMARCA2-BRD inhibitors and optimized the physicochemical conditions including pH, salt concentrations and detergent levels. Through an established AlphaScreen-based high-throughput screening assay against an in-house compound library, DCSM06 was identified as a novel SMARCA2-BRD inhibitor with an IC₅₀ value of 39.9±3.0 μmol/L. Surface plasmon resonance demonstrated the binding between SMARCA2-BRD and DCSM06 (K_d=38.6 μmol/L). A similarity-based analog search led to identification of DCSM06-05 with an IC₅₀ value of 9.0±1.4 μmol/L. Molecular docking was performed to predict the binding mode of DCSM06-05 and to decipher the structural basis of the infiuence of chemical modifications on inhibitor potency. DCSM06-05 may be used as a starting point for further medicinal chemistry optimization and could function as a chemical tool for SMARCA2-related functional studies.

中文翻译：

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从高通量筛选分析中鉴定靶向SMARCA2溴结构域的小分子抑制剂。

SMARCA2是开关/蔗糖非发酵（SWI / SNF）染色质重塑复合物的关键催化亚基。SMARCA2的失调与多种疾病（包括某些癌症）有关。SMARCA2是一种多结构域蛋白，包含一个溴结构域（BRD），该结构域特异性识别组蛋白尾巴中的乙酰化赖氨酸残基，因此在染色质重塑中起重要作用。最近发现了许多靶向其他BRD的强效特异性抑制剂，已被广泛用于癌症治疗和生物学研究。但是，特别缺少针对SMARCA2-BRD的命中发现。迄今为止，针对SMARCA2-BRD接口的报道的高通量筛选（HTS）分析很少。在这项研究中，我们开发了用于发现SMARCA2-BRD抑制剂的AlphaScreen HTS系统，并优化了物理化学条件，包括pH，盐浓度和去污剂含量。通过针对内部化合物库的基于AlphaScreen的高通量筛选测定，DCSM06被鉴定为具有IC的新型SMARCA2-BRD抑制剂₅₀值为39.9±3.0μmol/ L。表面等离振子共振表明SMARCA2-BRD和DCSM06之间的结合（K _d = 38.6μmol / L）。基于相似度的模拟搜索可鉴定出DCSM06-05，IC ₅₀值为9.0± 1.4μmol / L。进行了分子对接，以预测DCSM06-05的结合模式并破译化学修饰对抑制剂效价影响的结构基础。DCSM06-05可以用作进一步优化药物化学的起点，并且可以用作SMARCA2相关功能研究的化学工具。