Department of Enzymology, Institute of Biochemistry and Biotechnology, Martin-Luther-University Halle-Wittenberg, Kurt-Mothes-Strasse 3, 06120 Halle/Saale (Germany).
Angew Chem Int Ed Engl. 2014 Sep 26;53(40):10728-32. doi: 10.1002/anie.201402679. Epub 2014 Aug 11.
Sirtuins are NAD(+)-dependent deacetylases acting as sensors in metabolic pathways and stress response. In mammals there are seven isoforms. The mitochondrial sirtuin 5 is a weak deacetylase but a very efficient demalonylase and desuccinylase; however, its substrate acyl specificity has not been systematically analyzed. Herein, we investigated a carbamoyl phosphate synthetase 1 derived peptide substrate and modified the lysine side chain systematically to determine the acyl specificity of Sirt5. From that point we designed six potent peptide-based inhibitors that interact with the NAD(+) binding pocket. To characterize the interaction details causing the different substrate and inhibition properties we report several X-ray crystal structures of Sirt5 complexed with these peptides. Our results reveal the Sirt5 acyl selectivity and its molecular basis and enable the design of inhibitors for Sirt5.
沉默调节蛋白是 NAD(+)依赖的去乙酰化酶，作为代谢途径和应激反应的传感器。在哺乳动物中有七种同工酶。线粒体沉默调节蛋白 5 是一种弱去乙酰化酶，但却是一种非常有效的脱酰基酶和脱琥珀酰酶；然而，其底物酰基特异性尚未得到系统分析。在此，我们研究了一种由氨基甲酰磷酸合成酶 1 衍生的肽底物，并系统修饰赖氨酸侧链，以确定 Sirt5 的酰基特异性。从这一点出发，我们设计了六个有效的基于肽的抑制剂，与 NAD(+)结合口袋相互作用。为了阐明导致不同底物和抑制特性的相互作用细节，我们报告了 Sirt5 与这些肽结合的几个 X 射线晶体结构。我们的结果揭示了 Sirt5 的酰基选择性及其分子基础，并为 Sirt5 的抑制剂设计提供了依据。
