Interaction of human α-synuclein and Parkinson's disease variants with phospholipids -: Structural analysis using site-directed mutagenesis
Interaction of human α-synuclein and Parkinson's disease variants with phospholipids -: Structural analysis using site-directed mutagenesis
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DOI：
10.1074/jbc.m004851200
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发表时间：
2000-11-03
影响因子：
4.8
通讯作者：
George, JM
中科院分区：
文献类型：
--
作者：
Perrin, RJ;Woods, WS;George, JM
α-突触核蛋白在神经退行性疾病中起核心作用，对鸣禽的研究表明它在发育性突触可塑性中具有正常功能。多种观察结果表明，该蛋白质在膜和细胞质之间分配，这种行为显然是由其与可交换载脂蛋白的保守结构相似性所赋予的。在此我们表明，结合脂质的能力广泛分布在第3、4和5外显子（编码第1 - 102位残基）。与含磷脂酰丝氨酸的囊泡结合需要所有三个外显子都存在，而与磷脂酸的结合可由三者中的任何一个介导。与“A2类”螺旋结合机制一致，沿着预测的α-螺旋的疏水面引入带电残基以及对保守赖氨酸进行生物素化（这些赖氨酸位于界面区域）会破坏脂质结合。圆二色光谱显示，脂质诱导的α-螺旋含量与结合含磷脂酰丝氨酸囊泡的程度之间存在普遍的相关性。与帕金森病相关的两个点突变对脂质结合或α-螺旋性影响很小（A30P）或没有影响（A53T）。这些结果与以下假设一致：α-突触核蛋白的正常功能取决于在特定磷脂存在下发生大的构象变化的能力。
alpha -Synuclein has been centrally implicated in neurodegenerative disease, and a normal function in developmental synaptic plasticity has been suggested by studies in songbirds. A variety of observations suggest the protein partitions between membrane and cytosol, a behavior apparently conferred by a conserved structural similarity to the exchangeable apolipoproteins. Here we show that the capacity to bind lipids is broadly distributed across exons 3, 4, and 5 (encoding residues 1-102), Binding to phosphatidylserine-containing vesicles requires the presence of all three exons, while binding to phosphatidic acid can be mediated by any one of the three. Consistent with a "class A2" helical binding mechanism, lipid association is disrupted by introduction of charged residues along the hydrophobic face of the predicted cu-helix and also by biotinylation of conserved lysines (which line the interfacial region). Circular dichroism spectroscopy reveals a general correlation between the amount of lipid-induced alpha -helix content and the degree of binding to PS-containing vesicles. Two point mutations associated with Parkinson's disease have little (A30P) or no (A53T) effect on lipid binding or a-helicity. These results are consistent with the hypothesis that alpha -synuclein's normal functions depend on an ability to undergo a large conformational change in the presence of specific phospholipids.