Control of Executioner Caspases with an Allosteric Switch

描述（由申请方提供）：蛋白质功能的正交控制允许来自相关蛋白质家族的一种蛋白质失活，从而可以评估其独特的生物学功能。我们建议开发一种新的正交控制，称为变构开关，在caspase家族。胱天蛋白酶是半胱氨酸蛋白酶，其通过切割靶蛋白的离散选择来执行细胞死亡，这最终导致细胞凋亡。半胱天冬酶具有大的中央空腔，其可以被小分子变构抑制。半胱天冬酶被认为是治疗癌症（半胱天冬酶激活剂）或中风、心脏病发作和阿尔茨海默病（半胱天冬酶抑制剂）的良好靶标。不幸的是，目前可用的小抑制剂，结合在胱天蛋白酶的活性位点的相似性，不允许明确的12个不同的胱天蛋白酶的确切作用的鉴定。我们将使用定向进化和计算蛋白质设计的组合，在半胱天冬酶-3，-6和-7中引入变构开关。当我们选择或设计的小分子效应物与进化的变构位点结合时，胱天蛋白酶活性将被抑制。这个开关将允许我们一次关闭一种类型的caspase，以确定哪些蛋白质被caspase-3或-6或-7特异性切割。被切割的蛋白质本身就很有趣，因为它们的切割是促凋亡的，这意味着它们会导致细胞死亡。诱导细胞凋亡的能力是有用的癌症药物的标志。我们的研究可能会提示哪种半胱天冬酶应该被靶向用于治疗哪种疾病。在这些半胱天冬酶中成功实现变构开关将为其他九种半胱天冬酶中的变构开关铺平道路，并最终进入缺乏生物信息的其他蛋白质家族。 非技术性总结：疾病治疗的中心问题是知道哪种蛋白质应该被靶向治疗哪种疾病。我们将在半胱天冬酶中开发的变构开关技术只允许一种类型的蛋白质被药物关闭，以确定哪种疾病可以通过靶向该特定蛋白质来有效治疗。我们专注于半胱天冬酶蛋白，它可以导致癌细胞死亡。

DESCRIPTION (provided by applicant): Orthogonal control of protein function allows one protein from a family of related proteins to be inactivated so that its unique biological function can be assessed. We propose development of a new kind of orthogonal control, called allosteric switches, in the caspase family. Caspases are cysteine proteases that execute cell death by cleaving a discrete selection of target proteins, which ultimately leads to apoptosis. Caspases have a large central cavity that can be allosterically inhibited by small molecules. Caspases are believed to be good targets for treatment of cancer (caspase activators) or stroke, heart attack and Alzheimer's Disease (caspase inhibitors). Unfortunately the similarities in currently available small inhibitors that bind at the caspase active sites have not allowed unambiguous identification of the precise roles of the twelve different caspases. We will use a combination of directed evolution and computational protein design to introduce an allosteric switch in caspases-3, -6, and -7. When the small molecule effector we have selected or designed against binds to the evolved allosteric site, caspase activity will be inhibited. This switch will allow us to turn off one type of caspase at a time to determine what proteins are specifically cleaved by caspase-3 or -6 or -7. The cleaved proteins themselves are inherently interesting, because their cleavage is proapoptotic, meaning they lead to cell death. The ability to induce apoptosis is the hallmark of a useful cancer drug. Our studies may suggest which caspase should be targeted for treating which disease. Successful implementation of allosteric switches in these caspases will pave the way for allosteric switches in the other nine caspases and ultimately into other families of proteins where biological information is lacking. NON-TECHNICAL SUMMARY: The central problem in disease treatment is knowing which protein should be targeted to treat which disease. The allosteric switch technology we will develop in caspases allows just one type of protein to be turned off by a drug, to determine which disease could be effectively treated by targeting that particular protein. We focus on caspase proteins, which can cause cancer cells to die.