Determinants of Notch-Sparing Gamma-Secretase Inhibition

保留缺口的γ分泌酶抑制的决定因素

• 批准号: 8488025
• 负责人: Michael S Wolfe
• 金额: $ 8.81万
• 依托单位: BRIGHAM AND WOMEN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-04-01 至 2015-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8488025
• 关键词: Address; Affect; Alzheimer' s Disease; Amyloid; Amyloid Proteins; Amyloid beta-Protein Precursor; Aspartic Endopeptidases; Binding; Biochemical; Cell Differentiation process; Chimera organism; Cleaved cell; Clinical Trials; Complex; Development; Early Onset Familial Alzheimer' s Disease; Enzymes; Event; Goals; Integral Membrane Protein; Length; Membrane; Mind; Modeling; Multienzyme Complexes; Mutation; Pathogenesis; Pathway interactions; Peptide Hydrolases; Peptides; Pharmaceutical Preparations; Protein Precursors; Proteins; Proteolysis; Side; Signal Pathway; Site; Testing; Toxic effect; Transmembrane Domain; Work; design; drug candidate; enzyme substrate; extracellular; familial Alzheimer disease; gamma secretase; inhibitor/antagonist; interest; mutant; neurotoxic; notch protein; peptide A; presenilin; presenilin-1; public health relevance; research study; secretase; self assembly; therapeutic enzyme

DESCRIPTION (provided by applicant): The 4 kDa amyloid ?-protein (A?) is strongly implicated in the pathogenesis of Alzheimer's disease (AD). A? is produced through successive proteolysis of the type I integral membrane amyloid ?-protein precursor (APP), first on the lumen/extracellular side by the membrane-tethered ?-secretase and then within the transmembrane domain (TMD) by ?-secretase, a membrane-embedded aspartyl protease complex that contains the multi-pass presenilin as the catalytic component. Cleavage by ?-secretase determines the length of the A? peptide at the C-terminus, with longer forms of A? containing more of the TMD and being much more prone to self-assembly into neurotoxic aggregates. Although ?-secretase is considered an important target for the development of AD therapeutics, the enzyme cleaves a variety of other type I integral membrane proteins, most notably Notch receptors. Proteolysis of Notch with attendant release of its intracellular domain is part of a signaling pathway that is central to many types of cell differentiation events, and inhibition of this pathway with ?-secretase inhibitors (GSIs) results in severe toxicities that are unacceptable for an AD drug. Nevertheless, the discovery of GSIs that are selective for APP over Notch (so-called "Notch-sparing" GSIs) has led to the advancement of several candidates into clinical trials. However, the means by which these compounds selectively inhibit the protease complex are unknown, and an understanding of their mechanisms of selectivity might reveal strategies for developing more selective agents. The goal of this project is to identify substrate and enzyme determinants that confer selectivity for APP vis-?-vis Notch of Notch-sparing ?-secretase inhibitors. With this goal in mind, specific aims are proposed to address the following questions: (1) What regions/residues of APP and Notch confer substrate selectivity of Notch-sparing GSIs? (2) What is the potency and selectivity of Notch-sparing GSIs for ?-secretase carrying familial AD mutations? (3) What is the potency and selectivity of Notch-sparing GSIs for PS1 vs. PS2 ?-secretase? The identification of substrate and enzyme determinants of APP/Notch selectivity for these compounds should provide important information relevant to where these compounds bind and how that binding might result in allosteric changes that confer substrate selectivity.

描述(申请人提供)：4 kDa淀粉样蛋白(A？)与阿尔茨海默病(AD)的发病机制密切相关。一个?是通过I型完整膜淀粉样蛋白前体(APP)的连续蛋白分解产生的，首先在管腔/细胞外侧由膜系留？分泌酶产生，然后在跨膜区(TMD)内由？-分泌酶产生，？-分泌酶是一种包埋在膜中的天冬氨酸蛋白酶复合体，其中包含多通道的早老素作为催化成分。分泌酶的切割决定了A？C-末端有较长形式的A？含有更多的TMD，更容易自组装成神经毒性聚集体。尽管？-分泌酶被认为是AD治疗发展的一个重要靶点，但该酶还能裂解多种其他I型完整的膜蛋白，最著名的是Notch受体。Notch蛋白水解酶及其胞内结构域的释放 信号通路的一部分，在许多类型的细胞分化事件中起中心作用，用分泌酶抑制剂(GSI)抑制这一通路会导致严重的毒性 对于AD药物来说是不可接受的。然而，对APP比Notch具有选择性的GSI的发现(所谓的“保留Notch”GSI)已经导致了几个候选药物进入临床试验。然而，这些化合物选择性抑制蛋白酶复合体的方法尚不清楚，了解它们的选择性机制可能会揭示开发更具选择性的试剂的策略。该项目的目标是确定底物和酶决定因素，赋予APP相对于Notch的选择性--Notch-Sparing？-分泌酶抑制剂。考虑到这一目标，提出了解决以下问题的具体目标：(1)APP和Notch的哪些区域/残基赋予Notch-Sparing GSI底物选择性？(2)Notch-Sparing GSI对携带家族性AD突变的分泌酶的效力和选择性是什么？(3)Notch-Sparing GSI对PS1和PS2-分泌酶的效力和选择性是什么？识别这些化合物APP/Notch选择性的底物和酶决定因素应该提供与这些化合物结合在哪里以及这种结合如何导致变构变化从而赋予底物选择性相关的重要信息。