Isotype selective sirtuin inhibitors

Sirtuins是NAD+依赖性蛋白质脱酰基酶，其从组蛋白和其他底物蛋白质中赖氨酸的ε-氨基上切下乙酰基以及其他酰基。它们被认为是代谢和表观遗传学之间的联系。人类基因组编码七种sirtuin同种型，Sirt 1 -7。人类Sirt 2活性的失调与癌症、炎症和神经变性的发病机制相关，因此使Sirt 2成为药物干预的有希望的靶点。在以前的工作中，我们已经确定了sirtuin重排配体（SirReals）作为一类新的高度有效的Sirt 2抑制剂，具有已证实的细胞活性。此外，这些抑制剂显示出非常高的选择性Sirt 2之间的sirtuin同种型Sirt 1 -6。结合Sirt 2-SirReal复合物的晶体结构，广泛的结构活性关系研究使我们能够阐明SirReal介导的Sirt 2选择性抑制的独特模式。基于这些知识，我们开发了一个平台来产生Sirt 2选择性亲和探针。生物素化的Sirt 2选择性亲和探针为SirReals提供了新的应用，例如生物物理表征，基于片段的筛选和亲和下拉测定。在该项目中，我们将进一步利用该平台开发具有特定功能的新型Sirt 2选择性亲和探针，如荧光标记，HaloTag反应性接头，疏水标签，如金刚烷基，以促进疏水标签诱导的Sirt 2降解，或应诱导Cereblon依赖性Sirt 2降解的沙利度胺标签。这些基于SirReal的探针将成为研究Sirt 2生物学的重要工具，并涵盖具有治疗潜力的实体。通过从Sirt 2-SirReals共晶体结构和分子建模研究中获得的对Sirt 2选择性抑制的结构洞察，我们将优化SirReals以获得更好的水溶性，从而优化生物学评价。最后，基于可用的晶体结构和对接研究，我们将合理地调节SirReals的Sirt 2选择性，以使用它们作为起始点来获得其他沉默调节蛋白同种型的选择性抑制剂。我们将重点关注亚型Sirt 1和7，这是非常有趣的，其中强效和高选择性抑制剂的需求量很大。虚拟筛选和基于结构的优化将用于提供新的化学型和优化的命中。这些反过来将是研究沉默调节蛋白生物学及其治疗潜力的有价值的工具。

Sirtuins are NAD+-dependent protein deacylases that cleave off acetyl groups, as well as other acyl groups, from the epsilon-amino group of lysines in histones and other substrate proteins. They are considered as link between metabolism and epigenetics. The human genome encodes seven sirtuin isotypes, Sirt1-7. Dysregulation of human Sirt2 activity has been associated with the pathogenesis of cancer, inflammation, and neurodegeneration, thus making Sirt2 a promising target for pharmaceutical intervention. In previous work we have identified the sirtuin rearranging ligands (SirReals) as a novel class of highly potent Sirt2 inhibitors with proven cellular activity. Furthermore, these inhibitors showed a very high selectivity for Sirt2 among the sirtuin isotypes Sirt1-6. Extensive structure activity relationship studies in combination with crystal structures of Sirt2-SirReal complexes enabled us to elucidate the unique mode of Sirt2 selective inhibition mediated by the SirReals. Based on this knowledge we have developed a platform to generate Sirt2-selective affinity probes. A biotinylated Sirt2-selective affinity probe offers new applications for SirReals, such as biophysical characterization, fragment-based screening, and affinity pull-down assays. Within this project we will exploit this platform further to develop new Sirt2-selective affinity probes with specific functionalities, like fluorescent labels, HaloTag reactive linkers, hydrophobic tags, like adamantyl, to promote hydrophobic tagging-induced Sirt2 degradation, or a thalidomide-tag that should induce Cereblon-dependent Sirt2 degradation. These SirReal-based probes will be important tools for studying Sirt2 biology and encompass entities with therapeutic potential. Guided by the structural insight on Sirt2-selective inhibition obtained from Sirt2-SirReals co-crystal structures and molecular modelling studies, we will optimize the SirReals for better aqueous solubility for optimized biological evaluation. Finally, based on available crystal structures and docking studies we will rationally modulate the Sirt2 selectivity of the SirReals to use them as starting points to obtain selective inhibitors of other sirtuin isotypes. We will focus on the subtypes Sirt1 and 7 that are highly interesting and where potent and highly selective inhibitors are in great demand. Virtual screening and structure-based optimization will be used to provide novel chemotypes and optimized hits. These in turn will be valuable tools to study sirtuin biology and its therapeutic potential.