hERG钾离子通道的小分子荧光探针研究

发布时间：2018-05-09 06:57

本文选题：hERG钾离子通道 + 小分子荧光探针　；参考：《山东大学》2016年硕士论文

【摘要】：hERG (human ether-a-go-go related gene)编码的快速激活型延迟整流钾电流(IKr)钾离子通道在心脏动作电位复极化过程中具有关键作用。当hERG发生突变或hERG通道被药物阻滞时,可引起遗传性或获得性长QT间期综合征(LQTS)。由于不同种类药物对hERG通道产生阻滞作用而引起长QT综合征,药物的安全性已经在药物研发和临床研究中引起关注,因此hER G通道已经作为候选药物心脏毒性筛选的重要靶点。此外,初步研究表明hERG在某些肿瘤细胞中的表达显著上调,而在肿瘤细胞相应的正常细胞中不表达或表达较低,而且发现hERG通道与肿瘤的分化、凋亡、繁殖等密切相关,预示hERG将有可能作为肿瘤的新型生物标记物。因此,对hERG通道的系统生理病理研究将对新药临床前研究中的心脏毒性安全性评价和癌症发生机制的研究具有重要的科学意义和临床价值。近年来,随着荧光技术的快速发展,小分子荧光探针以其灵敏度高、操作简便、体积小等特点,已经广泛应用于蛋白质、核酸等重要生物分子的生物学和药理学检测中,对疾病机制探讨、临床诊断及药物筛选等领域具有重要的意义。小分子荧光探针通常由两部分组成：药效基团部分和荧光基团部分。药效基团与目标生物分子成高亲和力结合,继而荧光基团通过激发而发射荧光以标记蛋白质。本文选取hERG钾离子通道的抑制剂阿司咪唑和E-4031与通道主要结合部位的结构作为药效团,以香豆素类、萘二酰亚胺类、BD-C1、SBD-C1、Cy5类具有良好光学性质的化合物作为荧光团,通过烷基链将两者相连,设计合成了hERG通道的小分子荧光探针,并对其进行了光学性质的检测、hERG钾离子通道的亲和力测试、细胞的荧光成像评价以及细胞毒性测试。结果显示,所合成的hERG钾通道的小分子荧光探针具有良好的光学性质、较高的亲和力,可选择性的标记hERG通道,并且其细胞毒性较小。综上所述,通过本课题对hERG通道荧光探针的研究,以这些探针分子作为工具对hERG通道进行标记,将有可能为hERG钾离子通道的生理病理研究提供新的帮助,若利用所得到的荧光探针进一步进行hERG通道抑制剂的筛选研究,将对新药心脏毒性安全性评价具有重要的意义。此外,通过探针分子对肿瘤细胞的标记也将为肿瘤的研究提供新的启示。
[Abstract]:HERG ether-a-go-go related encoding fast activated delayed rectifier potassium current (IKR) potassium channel plays a key role in the repolarization of cardiac action potential. When hERG mutates or when hERG channels are blocked by drugs, it may cause hereditary or acquired long QT interval syndrome (LQTS). Long QT syndrome is caused by the blocking effect of different drugs on hERG channel. The safety of hER G channel has attracted much attention in drug development and clinical research. Therefore, hER G channel has been an important target for the screening of cardiac toxicity of drug candidates. In addition, preliminary studies showed that the expression of hERG was significantly up-regulated in some tumor cells, but not expressed or low in the corresponding normal cells of tumor cells. Furthermore, it was found that hERG channels were closely related to tumor differentiation, apoptosis and reproduction. This indicates that hERG may be a new biomarker for tumors. Therefore, the study of systemic physiology and pathology of hERG channel will be of great scientific significance and clinical value in evaluating the safety of cardiac toxicity and studying the mechanism of cancer in the preclinical study of new drugs. In recent years, with the rapid development of fluorescence technology, small molecular fluorescent probes have been widely used in the biological and pharmacological detection of proteins, nucleic acids and other important biomolecules because of their high sensitivity, simple operation and small size. It is of great significance to explore the mechanism of disease, clinical diagnosis and drug screening. Small molecular fluorescence probes usually consist of two parts: the effector group and the fluorescence group. The effector groups bind to target biomolecules with high affinity, and then fluorescence groups emit fluorescence to label proteins by excitation. In this paper, the structures of the main binding sites of hERG potassium channel inhibitor, Alimidazole and E-4031, were selected as pharmacophore groups. Coumarins and naphthalenediimide compounds with good optical properties were used as fluorescent groups. The small molecular fluorescence probes of hERG channel were designed and synthesized by linking them with alkyl chain. The optical properties of these probes were tested for their affinity, fluorescence imaging evaluation and cytotoxicity test. The results show that the synthesized hERG potassium channel fluorescent probe has good optical properties, high affinity, selective labeling of hERG channel, and its cytotoxicity is relatively small. In conclusion, the study of hERG channel fluorescent probes and the labeling of hERG channels with these probe molecules may provide new help for the physiological and pathological study of hERG potassium channels. If the fluorescent probe is used to screen hERG channel inhibitors further, it will be of great significance to evaluate the cardiac toxicity safety of new drugs. In addition, the labeling of tumor cells by probe molecules will provide new inspiration for tumor research.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：R914

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