Control of Executioner Caspases with an Allosteric Switch

用变构开关控制刽子手半胱天冬酶

• 批准号: 8630234
• 负责人: Jeanne Ann Hardy
• 金额: $ 25.84万
• 依托单位: UNIVERSITY OF MASSACHUSETTS AMHERST
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-01 至 2018-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8630234
• 关键词: Active Sites; Allosteric Regulation; Allosteric Site; Alzheimer' s Disease; Apoptosis; Apoptotic; Aspartic Endopeptidases; Binding; Binding Sites; Biological; Budgets; Caspase; Categories; Cell Death; Cells; Chemicals; Clinical Trials; Complex; Cysteine; Cysteine Protease; Development; Direct Costs; Disease; Drug Targeting; Engineering; Enzymes; Event; Family; Funding; Goals; Grant; Individual; Lead; Life; Ligands; Link; Malignant Neoplasms; Maps; Marketing; Mediating; Methods; Molecular; Myocardial Infarction; Nerve Degeneration; Neurodegenerative Disorders; Notification; Paper; Patients; Phosphorylation; Phosphorylation Inhibition; Phosphorylation Site; Phosphotransferases; Play; Process; Protein Region; Publishing; Regulation; Role; Site; Stroke; Structure; Subgroup; United States National Institutes of Health; Wages; Work; Zinc; base; cancer cell; cancer therapy; comparative; design; effective therapy; inhibitor/antagonist; insight; interest; killings; member; novel; prevent; research study

Caspases are the cysteine proteases that control apoptotic cell death. If caspases can be activated, cancer cells die; conversely inhibiting caspases could prevent cell death in diseases like heart attack and stroke. Thus there has been significant interest in caspases as drug targets. This interest was heightened when caspase-6 was discovered to play a central role in neurodegenerative diseases. Unfortunately, to date, no caspase-directed therapies are on the market, primarily because work has focused on targeting the active site, which is the most overlapping and conserved region of the family. It is becoming increasingly clear that each caspase is regulated in a unique and complex manner so the most promising avenue for achieving caspase-specific inhibition may be by harnessing allosteric sites. In order to target a specific caspase or group of caspases allosterically, it is essential to understand the differences between individual caspases and the similarities within subgroups in the caspase family. Thus, the goal of this project is understand how phosphorylation and zinc contribute to regulation of caspase activity. Understanding the roles of phosphorylation or zinc binding alone provides critical information about natural regulatory processes for each member of the apoptotic caspases. Together these sites highlight key sensitive regions that allow strategic control of caspase function. Caspases are extensively phosphorylated. Most phosphorylation events lead to inactivation of caspase function. Our first approach uses methods we have developed for structural analysis of phosphomimetic and phosphorylated versions of caspases. These structures uncover the mechanism by which phosphorylation prevents caspase activity and also identify key regions of conformational control, which are functional allosteric sites. Second, various caspases can be inhibited by zinc, which has also been linked to apoptosis and Alzheimer's Disease. We are applying anomalous x-ray diffraction experiments to identify and characterize novel zinc-binding sites in caspases. Both of these approaches: phosphorylation and zinc-binding have helped us previously to identify new allosteric sites in caspases. By systematically applying these approaches, we can comprehensively map allosteric sites that are used across the caspase family as well as unique sites that are found only on one particular caspase. Our approaches are designed to provide the molecular details of allosteric control as well as assess the biological relevance of these mechanisms. The comparative map of caspase allostery by phosphorylation and zinc binding that we are generating will enable us to select the most appropriate regulatory sites for optimal control of caspase function and for effective treatment of diseases that involve caspases.

胱天蛋白酶是控制凋亡细胞死亡的半胱氨酸蛋白酶。如果可以激活胱天蛋白酶，癌症 细胞死亡；相反，抑制胱天蛋白酶可以防止心脏病发作和中风等疾病中的细胞死亡。 因此，作为药物靶标的胱天蛋白酶引起了重大兴趣。当这种兴趣在 发现caspase-6在神经退行性疾病中起着核心作用。不幸的是，迄今为止，没有 caspase导向疗法正在市场上，主要是因为工作重点是针对活动 地点，这是家庭中最重叠和保守的地区。越来越清楚 每个caspase以独特而复杂的方式进行调节，因此实现最有希望的途径 caspase特异性抑制可能是通过利用变构位点。为了针对特定的caspase或 一组胱天蛋白酶变构，必须了解单个caspase之间的差异 以及caspase家族中亚组中的相似之处。因此，该项目的目标是了解 磷酸化和锌有助于调节caspase活性。了解 仅磷酸化或锌结合提供有关自然调节过程的关键信息 凋亡胱天蛋白酶的每个成员。这些站点共同强调了关键敏感区域，允许 caspase功能的战略控制。 胱天蛋白酶被广泛磷酸化。大多数磷酸化事件导致 caspase函数。我们的第一种方法使用我们开发的方法来进行结构分析 胱天蛋白酶的磷酸化和磷酸化版本。这些结构通过 哪种磷酸化可以防止胱天冬酶活性，还确定了构象控制的关键区域， 是功能变构位点。第二，锌可以抑制各种胱天蛋白酶，这也有 与凋亡和阿尔茨海默氏病有关。我们正在应用异常的X射线衍射 鉴定和表征胱天蛋白酶中新型锌结合位点的实验。这两种方法： 磷酸化和锌结合帮助我们以前鉴定了胱天蛋白酶中新的变构位点。经过 系统地采用这些方法，我们可以全面绘制所使用的变构网站 在caspase家族以及仅在一个特定caspase上发现的独特站点。我们的 方法旨在提供变构控制的分子细节，并评估 这些机制的生物学相关性。通过磷酸化的胱天蛋白酶变构的比较图 我们正在生成的锌结合将使我们能够为 最佳控制caspase功能和有效治疗涉及胱天蛋白酶的疾病。