Selective modulation of y-secretase processing through substrate binding

通过底物结合选择性调节 γ 分泌酶加工

• 批准号: 7662735
• 负责人: THOMAS L KUKAR
• 金额: $ 9万
• 依托单位: MAYO CLINIC JACKSONVILLE
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-04-01 至 2011-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7662735
• 关键词: Abeta synthesis; Address; Adverse effects; Affect; Alzheimer' s Disease; Amino Acids; Amyloid beta-Protein Precursor; Anti-Inflammatory Agents; Anti-inflammatory; Binding; Biology; C-terminal; Chemicals; Cleaved cell; Clip; Complex; Crystallography; Data; Dementia; Development; Dimerization; Elderly; Enzymes; Event; Future; Instruction; Investigation; Label; Lead; Link; Mammalian Cell; Maps; Mass Spectrum Analysis; Membrane; Membrane Proteins; Mentors; Methods; Molecular Biology; Mutagenesis; Natural regeneration; Notch Signaling Pathway; Pathway interactions; Pattern; Peptide Hydrolases; Peptides; Pharmaceutical Preparations; Phase; Play; Positioning Attribute; Principal Investigator; Process; Production; Protein Biochemistry; Protein C; Proteolysis; Reporting; Research; Research Personnel; Resolution; Risk; Role; Signal Pathway; Signal Transduction; Site; Specificity; System; Techniques; Testing; Therapeutic; Toxic effect; Training; Work; amyloid precursor protein processing; base; career; crosslink; design; gamma secretase; improved; in vivo; inhibitor/antagonist; insight; notch protein; novel; presenilin; prevent; programs; protective effect; protein protein interaction; research study; rho; secretase; small molecule; therapeutic target

DESCRIPTION (provided by applicant): Program Director/Principal Investigator (Last, First, Middle): Kukar, Thomas L. PROJECT SUMMARY (See instructions): Numerous lines of evidence support the hypothesis that selective targeting of A¿42 is an ideal therapeutic strategy to prevent and possibly treat Alzheimer's disease (AD), the major cause of dementia among the elderly. A class of compounds called ?-secretase modulators (GSMs) is being pursued as AD therapeutics because they are able to selectively alter A¿42 levels>. The first GSMs to be discovered were certain non- steroidal anti-inflammatory drugs (NSAIDs), which have been shown to selectively decrease A¿42 without global inhibition of APR processing. As whole GSMs minimally alter total Abeta production and instead shift the gamma-secretase cleavage site. The mechanism of GSMs has not been conclusively proven and different explanations for their activity have been proposed including: 1) allosteric binding to ?-secretase 2) inhibition of the Rho-ROCK signaling pathway 3) conformational changes in presenilin or 4) decreased dimerization of APR. We have recently discovered, using novel GSM photoaffinity probes, that these drugs do not label the y-secretase enzyme but instead modulate cleavage by binding to a the substrate, APP. We hypothesize that binding of APR by GSMs shifts the} position of APP-CTF in the membrane resulting in altered gamma-secretase cleavage. This hypothesis will be tested through the following specific aims: 1) investigate how substrate targeting by GSMs produces a shift in the cleavage pattern of A¿ using a combination of molecular biology and protein biochemistry 2) determine the specificity of GSMs for affecting APP proteolysis by ?-secretase in comparison to other substrates using mass spectrometry and 3) test if unnatural amino acids can be used to study proteolysis of APP-CTF¿ by ?-secretase. Aim 1 and career/technical training will take place during the mentored phase, which will facilitate the execution of Aims 2 and 3 during the independent phase. These studies should provide additional insight into the mechanisms whereby NSAIDs and other GSMs shift A¿ cleavage and how they exert their protective effects in vivo. This work will also guide future efforts to design more potent GSMs which will be useful as chemical probes for understanding the biology of ?-secretase and as potential therapeutics for Alzheimer's disease. RELEVANCE (See instructions): Alzheimer's disease (AD) is the most common type of dementia afflicting the elderly with no known cure. ?- secretase modulators (GSMs) are a promising class of drugs under investigation to treat AD. The proposed research will provide critical insight into how GSMs work and may ultimately lead to improved AD therapeutics.

描述（由申请人提供）： 项目主任/首席研究员（最后、第一个、中间）： Kukar, Thomas L. 项目摘要（参见说明）： 大量证据支持选择性靶向 A¿ 42 是预防和可能治疗阿尔茨海默病 (AD) 的理想治疗策略，阿尔茨海默病是老年人痴呆的主要原因，人们正在研究一类称为 β-分泌酶调节剂 (GSM) 的化合物作为 AD 治疗药物，因为它们能够选择性地治疗阿尔茨海默病。改变A?? 42 水平>. 第一个被发现的 GSM 是某些非甾体类抗炎药 (NSAID)，它们已被证明可以选择性地降低 A¿ 42 没有对 APR 加工进行全局抑制。由于整个 GSM 最小程度地改变了总 Abeta 的产生，而是转移了 γ 分泌酶裂解位点，因此 GSM 的机制尚未得到最终证实，并且对其活性提出了不同的解释，包括：1) 变构结合。 β-分泌酶 2) 抑制 Rho-ROCK 信号通路 3) 早老素的构象变化或 4) 减少 APR 的二聚化。使用新型 GSM 光亲和探针，这些药物不会标记 y-分泌酶，而是通过与底物 APP 结合来调节切割。我们发现 GSM 与 APR 的结合会改变 APP-CTF 在膜中的位置。该假设将通过以下具体目标进行检验：1）研究 GSM 的底物靶向如何产生 A¿结合分子生物学和蛋白质生物化学 2) 使用质谱法与其他底物相比，确定 GSM 对 β-分泌酶影响 APP 蛋白水解的特异性，以及 3) 测试非天然氨基酸是否可用于研究 APP-CTF 的蛋白水解¿目标 1 和职业/技术培训将在指导阶段进行，这将有助于在独立阶段执行目标 2 和 3。这些研究应为 NSAID 和其他 GSM 的转变机制提供更多见解。一个这项工作还将指导未来设计更有效的 GSM 的努力，这些 GSM 将可用作了解 β-分泌酶生物学的化学探针和阿尔茨海默氏病的潜在治疗方法（参见说明。 ）：阿尔茨海默病 (AD) 是一种最常见的老年痴呆症，目前尚无已知的治疗方法。β-分泌酶调节剂 (GSM) 是一类正在研究中治疗 AD 的有希望的药物。拟议的研究将为 GSM 的工作原理提供重要的见解，并可能最终改进 AD 疗法。