新型Sirtuin机理型抑制剂的设计合成与活性研究

Sirtuins, a class of enzymes known as nicotinamide adenine dinucleotide (NAD)-dependent lysine deacylases, belong to histone deacetylase, which have been extensively studied as potential targets for anti-cancer therapy in recent years. Five small molecular inhibitors has been approved by FDA or CFDA, which are all mechanism-based inhibitors. Therefore, design and synthesis of small molecular mechanism-based inhibitors become a powerful strategy for the development of drug targeting histone deacetylase. Based on our previous experience in the development of Sirtuin mechanism-based inhibitors, this project will start from acyl lysine, consider the “flexibility” or “rigidity” of the backbone of lysine, and introducing inhibitory groups (“thioamide”, “carboxamido”, “thiourea”,etc) aiming Sirtuin to design and synthesize a series of novel lysine analogues. After in vitro and cellular study, these analogues will be evaluated for the inhibitory potency and selectivity for Sirtuin. We will further investigate their anti-tumor activity and the structure-activity relationship. Novel Sirtuin mechanism-based inhibitors with high potency and selectivity are expected to facilitate the research and development of novel drugs targeting Sirtuin.

Sirtuin蛋白是一类烟酰胺腺嘌呤二核苷酸（NAD）依赖的去赖氨酸酰化酶，属于一种组蛋白去乙酰化酶，是近年来肿瘤治疗靶标的研究热点之一。目前已有5个组蛋白去乙酰化酶的小分子机理型抑制剂被FDA或CFDA批准上市，可见，机理型抑制剂的设计合成是开发该类靶向药物的有效策略。基于申请人前期对Sirtuin机理型抑制剂的研究基础，本项目以酰化赖氨酸为出发点，通过增加赖氨酸骨架的“柔性”或“刚性”，以及引入硫酰胺（thioamide）、甲酰胺基（carboxamido）或硫脲（thiourea）等导向Sirtuin的活性基团，进行全新设计合成一系列新型赖氨酸类似物，并开展体外和细胞水平的Sirtuin抑制活性、选择性以及后续抗肿瘤活性研究，考察其构效关系，以获得具有优异抑制活性和选择性的新型Sirtuin机理型抑制剂，为后续靶向药物研究与开发奠定基础。

Sirtuin蛋白是一类烟酰胺腺嘌呤二核苷酸（NAD）依赖的去赖氨酸酰化酶，属于一种组蛋白去乙酰化酶，是近年来肿瘤治疗靶标的研究热点之一。目前已有5个组蛋白去乙酰化酶的小分子机理型抑制剂被FDA或CFDA批准上市，可见，机理型抑制剂的设计合成是开发该类靶向药物的有效策略。本项目主要以半胱氨酸或赖氨酸为原料，完成了FLA、Lysine和Benzotriazole analogues等三大类化合物的合成，共计116个候选化合物（包括102个小分子化合物和14个多肽化合物）。通过体外和细胞水平的组蛋白去乙酰化酶抑制活性、选择性以及后续抗肿瘤活性研究，考察其构效关系，获得若干具有显著抑制活性和选择性的新型Sirtuin和HDAC机理型抑制剂。通过酶促动力学和分子对接研究，发现了半胱氨酸的L构型和硫原子更容易导向SIRT2的疏水口袋，解释了半胱氨酸衍生物抑制SIRT2的作用机制。更重要的是，通过稳定性、蛋白质组学、定点突变和酶促动力学等研究，揭示了我们开发的第一例SIRT2共价抑制剂1e的关键共价结合位点是第287位赖氨酸（K287），这一新发现将为SIRT2共价抑制剂的设计合成提供重要的依据，也为后续的以Sirtuin为靶向药物的研究与开发奠定坚实基础。