Mutant Protein A30P α-Synuclein Adopts Wild-type Fibril Structure, Despite Slower Fibrillation Kinetics
Mutant Protein A30P α-Synuclein Adopts Wild-type Fibril Structure, Despite Slower Fibrillation Kinetics
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DOI：
10.1074/jbc.m111.306902
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发表时间：
2012-03-30
影响因子：
4.8
通讯作者：
Rienstra, Chad M.
中科院分区：
文献类型：
--
作者：
Lemkau, Luisel R.;Comellas, Gemma;Rienstra, Chad M.
α -突触核蛋白（AS）与散发性和家族性帕金森病（PD）有关。在散发性疾病中，野生型AS在黑质多巴胺能神经元内纤维化并以路易小体的形式积累。错误折叠的AS的积累与这些神经元的死亡有关，这是PD的许多临床特征的基础。此外，AS中罕见的错义突变A30P与高渗透性常染色体显性PD相关，尽管其致病机制尚不清楚。在体外实验中，A30P AS比野生型（WT）蛋白纤维化更慢，并且有报道称其优先采用可溶性原纤维构象。这导致人们猜测A30P形成的聚集体在结构上与野生型AS不同。在这里，我们根据我们最近对全长WT原纤维的表征，对这些原纤维物种的化学位移和二级结构进行了详细的比较。我们对A30P AS原纤维进行了从头化学位移，并用它们来确定其二级结构。我们的研究结果表明，尽管A30P在体外形成原纤维的速度比WT慢，但所产生的原纤维的化学位移和二级结构高度一致，显示出保守的β -sheet核心。
alpha-Synuclein (AS) is associated with both sporadic and familial forms of Parkinson disease (PD). In sporadic disease, wild-type AS fibrillates and accumulates as Lewy bodies within dopaminergic neurons of the substantia nigra. The accumulation of misfolded AS is associated with the death of these neurons, which underlies many of the clinical features of PD. In addition, a rare missense mutation in AS, A30P, is associated with highly penetrant, autosomal dominant PD, although the pathogenic mechanism is unclear. A30P AS fibrillates more slowly than the wild-type (WT) protein in vitro and has been reported to preferentially adopt a soluble, protofibrillar conformation. This has led to speculation that A30P forms aggregates that are distinct in structure compared with wild-type AS. Here, we perform a detailed comparison of the chemical shifts and secondary structures of these fibrillar species, based upon our recent characterization of full-length WT fibrils. We have assigned A30P AS fibril chemical shifts de novo and used them to determine its secondary structure empirically. Our results illustrate that although A30P forms fibrils more slowly than WT in vitro, the chemical shifts and secondary structure of the resultant fibrils are in high agreement, demonstrating a conserved beta-sheet core.