Human sirtuin 5 (SIRT5) plays pivotal roles in metabolic pathways and other biological processes, and is involved in several human diseases including cancer. Development of new potent and selective SIRT5 inhibitors is currently desirable to provide potential therapeutics for related diseases. Herein, we report a series of new 3-thioureidopropanoic acid derivatives, which were designed to mimic the binding features of SIRT5 glutaryl-lysine substrates. Structure-activity relationship studies revealed several compounds with low micromolar inhibitory activities to SIRT5. Computational and biochemical studies indicated that these compounds exhibited competitive SIRT5 inhibition with respect to the glutaryl-lysine substrate rather than nicotinamide adenine dinucleotide cofactor. Moreover, they showed high selectivity for SIRT5 over SIRT1-3 and 6 and could stabilize SIRT5 proteins as revealed by thermal shift analyses. This work provides an effective substrate-mimicking strategy for future inhibitor design, and offers new inhibitors to investigate their therapeutic potentials in SIRT5-associated disease models.

人类 sirtuin 5 (SIRT5) 在代谢途径和其他生物过程中起关键作用，并与包括癌症在内的多种人类疾病有关。目前需要开发新的强效和选择性 SIRT5 抑制剂，为相关疾病提供潜在的治疗方法。在这里，我们报告了一系列新的 3-硫脲基丙酸衍生物，这些衍生物旨在模拟 SIRT5 戊二酰赖氨酸底物的结合特征。构效关系研究揭示了几种对 SIRT5 具有低微摩尔抑制活性的化合物。计算和生化研究表明，这些化合物对戊二酰赖氨酸底物而非烟酰胺腺嘌呤二核苷酸辅因子表现出竞争性 SIRT5 抑制作用。而且，他们对 SIRT5 的选择性高于 SIRT1-3 和 6，并且可以稳定 SIRT5 蛋白，如热位移分析所示。这项工作为未来的抑制剂设计提供了一种有效的底物模拟策略，并提供了新的抑制剂来研究它们在 SIRT5 相关疾病模型中的治疗潜力。