Herpesviral deubiquitinating enzymes (DUBs) were discovered in 2005, are highly conserved across the family, and are proving to be increasingly important players in herpesviral infection. EBV's DUB, BPLF1, is known to regulate both cellular and viral target activities, yet remains largely unstudied. Our work has implicated BPLF1 in a wide range of processes including infectivity, viral DNA replication, and DNA repair. Additionally, knockout of BPLF1 delays and reduces human B-cell immortalization and lymphoma formation in humanized mice. These findings underscore the importance of BPLF1 in viral infectivity and pathogenesis and suggest that inhibition of EBV's DUB activity may offer a new approach to specific therapy for EBV infections. We set out to discover and characterize small molecule inhibitors of BPLF1 deubiquitinating activity through high-throughput screening. An initial small pilot screen resulted in discovery of 10 compounds yielding >80% decrease in BPLF1 DUB activity at a 10 μM concentration. Follow-up dose response curves of top hits identified several compounds with an IC50 in the low micromolar range. Four of these hits were tested for their ability to cleave ubiquitin chains as well as their effects on viral infectivity and cell viability. Further characterization of the top hit, commonly known as suramin was found to not be selective yet decreased viral infectivity by approximately 90% with no apparent effects on cell viability. Due to the conserved nature of Herpesviral deubiquitinating enzymes, identification of an inhibitor of BPLF1 may prove to be an effective and promising new avenue of therapy for EBV and other herpesviral family members.

中文翻译：

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小分子筛选可鉴定出爱泼斯坦巴尔病毒去泛素化酶BPLF1的抑制剂。

疱疹病毒去泛素化酶（DUBs）于2005年发现，在整个家族中都高度保守，并被证明在疱疹病毒感染中起着越来越重要的作用。众所周知，EBV的DUB BPLF1可以调节细胞和病毒靶标的活性，但尚未得到广泛研究。我们的工作已将BPLF1牵涉到广泛的过程中，包括感染性，病毒DNA复制和DNA修复。此外，敲除BPLF1会延迟并减少人源化小鼠中人B细胞永生化和淋巴瘤的形成。这些发现强调了BPLF1在病毒感染性和发病机理中的重要性，并表明抑制EBV的DUB活性可能为针对EBV感染的特异性疗法提供新的方法。我们着手通过高通量筛选来发现和表征BPLF1去泛素化活性的小分子抑制剂。最初的小规模中试筛选发现了10种化合物，在10μM浓度下BPLF1 DUB活性降低> 80％。热门药物的后续剂量反应曲线确定了几种化合物的IC50在低微摩尔范围内。测试了这些命中中的四个命中的裂解泛素链的能力以及它们对病毒感染性和细胞生存力的影响。人们发现，通常被称为苏拉明的热门产品的进一步表征不是选择性的，而是将病毒感染性降低了约90％，而对细胞生存力没有明显影响。由于疱疹病毒去泛素化酶的保守性质，