Folding pathways for membrane-binding amphipathic helices

膜结合两亲螺旋的折叠途径

• 批准号: 107577-2011
• 负责人: Cornell, Rosemary
• 金额: $ 2.19万
• 依托单位: Simon Fraser University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=522069
• 关键词: Folding; pathways; membrane; binding; amphipathic

Many neuropathologies are associated with protein mis-folding into fibrils called "beta-amyloid", including Parkinson's Disease. A mis-folded form of the protein alpha-synuclein accumulates in certain neurons in the brains of people with PD, and causes cell death. When alpha-synuclein folds "properly" it coils into a helix and attaches to intracellular membrane vesicles that store neurotransmitters. Its productive function in regulating the fusion of these vesicles with the cell membrane and neurotransmitter release into the synapse is predicated upon this helical folding. If scientists could find a way to promote the native helical folding of alpha-synuclein and discourage the mis-folding into pathogenic proto-fibrils, then the neuronal cells might be rescued from cell death, and Parkinson's Disease symptoms might be reversed. We have discovered during our studies of an important metabolic enzyme, cytidylyltransferase (CCT), that alpha-synuclein resembles the tail portion of CCT in structure and function. But CCT, which is an enzyme that controls the synthesis of membrane phospholipids, does not mis-fold in cells. CCT, but not alpha-synuclein, contains a globular head domain that could prevent mis-folding of its own tail. Our proposal has three aims: 1). To characterize in parallel the structure and membrane-binding properties of synuclein and the CCT tail. 2). To determine if the CCT tail mis-folds into amyloidogenic particles or fibrils when it is missing a connection to its head domain. 3). To assess whether the CCT tail domain (if it does NOT mis-fold) can serve as a chaperone to prevent mis-folding of alpha-synuclein, or alternatively to assess whether a chimeric protein composed of the CCT head domain linked to alpha-synuclein - when added to alpha-synuclein can prevent misfolding. Our research will provide basic information about the causes of protein mis-folding.

许多神经病理与蛋白质错误折叠成纤维被称为“β-淀粉样蛋白”有关，包括帕金森氏症。一种错误折叠的α-突触核蛋白在帕金森病患者大脑中的某些神经元中积累，并导致细胞死亡。当α-突触核蛋白“正确”折叠时，它会卷曲成螺旋，并附着在储存神经递质的细胞膜囊泡上。它在调节这些囊泡与细胞膜的融合以及神经递质释放到突触中的生产功能是基于这种螺旋折叠。如果科学家们能找到一种方法来促进α-突触核蛋白的天然螺旋折叠，并阻止错误折叠成致病的原纤维，那么神经细胞可能会从细胞死亡中解救出来，帕金森氏症的症状可能会逆转。我们在对一种重要的代谢酶-胞苷酰转移酶(CCT)的研究中发现，α-突触核蛋白在结构和功能上与CCT的尾部相似。但CCT是一种控制膜磷脂合成的酶，它在细胞中不会错误折叠。CCT，但不是α-突触核蛋白，包含一个球状的头部结构域，可以防止自己的尾巴错误折叠。我们的建议有三个目标：1)。平行表征突触核蛋白和CCT尾部的结构和膜结合特性。2)。以确定当CCT尾部缺少与其头部结构域的连接时，是否错误折叠成淀粉样蛋白颗粒或纤维。3)。为了评估CCT尾部结构域(如果它没有错误折叠)是否可以作为伴侣来防止α-突触核蛋白的错误折叠，或者评估由CCT头部结构域组成的嵌合蛋白在与α-突触核蛋白相连时是否可以防止错误折叠。我们的研究将为蛋白质错误折叠的原因提供基本信息。