SIRT5已被涉及到各种生理过程和人类疾病，包括癌症。仍需要开发新型高效选择性的SIRT5抑制剂来研究与疾病相关的机制和治疗潜力。我们在此报道了一些新的ε-N-硫代谷氨酰赖氨酸衍生物，这些衍生物是按照SIRT5催化的脱酰基反应设计的。这些ε-N-硫代谷氨酰赖氨酸衍生物表现出强大的SIRT5抑制作用，其中具有潜力的光交联衍生物8对SIRT5的抑制最为强劲，IC50值为120 nM，对SIRT1-3和SIRT6的抑制较低。酶动力学试验表明，ε-N-硫代谷氨酰赖氨酸衍生物通过亮氨酸-底物竞争性方式抑制SIRT5。共结晶分析表明，8号化合物通过与SIRT5特定的残基进行氢键和静电相互作用，占据亮氨酸-底物结合位点，并可能定位于与NAD+反应并形成稳定的硫中间体。由于SIRT5:8晶体结构中观察到二氮化硅基团的位置不合适，8号化合物被观察到对SIRT5具有较低的光交联概率。本研究为开发类似药物的抑制剂和交联化学探针以进行SIRT5相关研究提供了有用信息。版权所有©2023 Elsevier Inc.。

SIRT5 has been implicated in various physiological processes and human diseases, including cancer. Development of new highly potent, selective SIRT5 inhibitors is still needed to investigate disease-related mechanisms and therapeutic potentials. We here report new ε-N-thioglutaryllysine derivatives, which were designed according to SIRT5-catalysed deacylation reactions. These ε-N-thioglutaryllysine derivatives displayed potent SIRT5 inhibition, of which the potential photo-crosslinking derivative 8 manifested most potent inhibition with an IC50 value of 120 nM to SIRT5, and low inhibition to SIRT1-3 and SIRT6. The enzyme kinetic assays revealed that the ε-N-thioglutaryllysine derivatives inhibit SIRT5 by lysine-substrate competitive manner. Co-crystallographic analyses demonstrated that 8 binds to occupy the lysine-substate binding site by making hydrogen-bonding and electrostatic interactions with SIRT5-specific residues, and is likely positioned to react with NAD+ and form stable thio-intermediates. Compound 8 was observed to have low photo-crosslinking probability to SIRT5, possibly due to inappropriate position of the diazirine group as observed in SIRT5:8 crystal structure. This study provides useful information for developing drug-like inhibitors and cross-linking chemical probes for SIRT5-related studies.Copyright © 2023 Elsevier Inc. All rights reserved.