BACKGROUND & AIMS: :The intracellular α-synuclein (α-syn) protein, whose conformational change and aggregation have been closely linked to the pathology of Parkingson's disease (PD), is highly populated at the presynaptic termini and remains there in the α-helical conformation. In this study, circular dichroism confirmed that natively unstructured α-syn in aqueous solution was transformed to its α-helical conformation upon addition of trifluoroethanol (TFE). Electrochemical and UV-visible spectroscopic experiments reveal that both Cu (I) and Cu (II) are stabilized, with the former being stabilized by about two orders of magnitude. Compared to unstructured α-syn (Binolfi et al., J. Am. Chem. Soc. 133 (2011) 194-196), α-helical α-syn stabilizes Cu (I) by more than three orders of magnitude. Through the measurements of H(2)O(2) and hydroxyl radicals (OH) in solutions containing different forms of Cu (II) (free and complexed by unstructured or α-helical α-syn), we demonstrate that the significantly enhanced Cu (I) binding affinity helps inhibit the production of highly toxic reactive oxygen species, especially the hydroxyl radicals. Our study provides strong evidence that, as a possible means to prevent neuronal cell damage, conversion of the natively unstructured α-syn to its α-helical conformation in vivo could significantly attenuate the copper-modulated ROS production.

背景与目标： : 细胞内 α-突触核蛋白 (α-syn) 蛋白的构象变化和聚集与Parkingson病 (PD) 的病理密切相关，在突触前末端高度聚集，并保留在 α-螺旋构象中。在这项研究中，圆二色性证实，加入三氟乙醇 (TFE) 后，水溶液中的原生非结构化 α-syn转化为其 α-螺旋构象。电化学和紫外可见光谱实验表明，Cu (I) 和Cu (II) 都是稳定的，前者稳定了大约两个数量级。与非结构化 α-syn (Binolfi等人，J. Am. Chem. Soc. 133 (2011) 194-196) 相比，α-螺旋 α-syn使Cu (I) 稳定超过三个数量级。通过测量含有不同形式的Cu (II) (游离并通过非结构化或 α-螺旋 α-syn络合) 的溶液中的H(2)O(2) 和羟基自由基 (OH)，我们证明了显着增强的Cu (I) 结合亲和力有助于抑制高毒性活性氧的产生，尤其是羟基自由基。我们的研究提供了有力的证据，表明作为防止神经元细胞损伤的一种可能手段，在体内将非结构化的 α-syn转化为其 α-螺旋构象可以显着减弱铜调节的ROS的产生。

BACKGROUND & AIMS: :Pathological examination of dementia with Lewy bodies patients identified the presence of abnormal α-synuclein (αSyn) aggregates in the presynaptic terminals. αSyn is involved in the regulation of soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complex. Importantly, αSyn-transgenic mouse and postmortem examination of patients with Parkinson's disease have demonstrated the abnormal distribution of SNARE protein in presynaptic terminals. In this study, we investigated the effects of SNARE dysfunction on endogenous αSyn using Snap25(S187A/S187A) mutant mice. These mice have homozygous knock-in gene encoding unphosphorylatable S187A-substituted synaptosomal-associated protein of 25 kDa (SNAP-25). The mice displayed a significant age-dependent change in the distribution of αSyn and its Ser(129)-phosphorylated form in abnormally hypertrophied glutamatergic nerve terminals in the striatum. Electron-microscopic analysis revealed the abnormally condensed synaptic vesicles with concomitant mislocalization of αSyn protein to the periactive zone in the glutamatergic nerve terminals. However, the Snap25(S187A/S187A) mutant mouse harbored no abnormalities in the nigrostriatal dopaminergic neurons. Our present results suggest that SNARE dysfunction is the initial trigger of mislocalization and accumulation of αSyn, and probably is an important pathomechanism of α-synucleinopathies.

背景与目标： : 路易体痴呆的病理检查患者发现突触前末端存在异常的 α-突触核蛋白 (α syn) 聚集体。Α syn参与可溶性N-乙基马来酰亚胺敏感因子附着蛋白受体 (snal) 复合物的调节。重要的是，α syn转基因小鼠和帕金森氏病患者的死后检查表明，突触前末端中snar蛋白的异常分布。在这项研究中，我们使用Snap25(S187A/S187A) 突变小鼠研究了snape功能障碍对内源性 α syn的影响。这些小鼠具有纯合的敲入基因，编码25 kDa (SNAP-25) 的不能磷酸化的S187A-substituted突触体相关蛋白。小鼠在纹状体异常肥大的谷氨酸能神经末梢中 α syn及其Ser(129) 磷酸化形式的分布显示出显着的年龄依赖性变化。电子显微镜分析显示，突触囊泡异常浓缩，伴随着 α syn蛋白错误定位到谷氨酸能神经末梢的周围活动区。然而，Snap25(S187A/S187A) 突变小鼠在黑质纹状体多巴胺能神经元中没有异常。我们目前的结果表明，圈套器功能障碍是 α syn错误定位和积累的最初触发因素，并且可能是 α-突触核蛋白病的重要病理机制。

BACKGROUND & AIMS: :Deposition of alpha-synuclein (alphaS) aggregates inside brain cells is a pathological hallmark of several neurodegenerative diseases, including Parkinson's disease (PD), and dementia with Lewy bodies (DLB). Recently, extracellular alphaS was detected in cerebrospinal fluid (CSF) and plasma of humans. We investigated whether CSF influences alphaS aggregation in vitro using fluorescence spectroscopy with thioflavin S and electron microscopy. We found that CSF obtained from Alzheimer's disease (AD) and DLB patients enhanced the alphaS fibril formation compared with tauopathy and non-central nervous system disease. Thus, CSF of AD and DLB characterized by aggregation of Abeta or alphaS might promote falphaS formation.

背景与目标： : 脑细胞内 α-突触核蛋白 (alpha) 聚集体的沉积是几种神经退行性疾病的病理标志，包括帕金森氏病 (PD) 和路易体痴呆 (DLB)。最近，在人类的脑脊液 (CSF) 和血浆中检测到细胞外alpha。我们使用硫黄素S的荧光光谱法和电子显微镜研究了CSF是否会影响alpha的体外聚集。我们发现，与tauopathy和非中枢神经系统疾病相比，从阿尔茨海默氏病 (AD) 和DLB患者获得的CSF增强了alpha原纤维的形成。因此，以Abeta或alpha聚集为特征的AD和DLB的CSF可能会促进falpha的形成。

BACKGROUND & AIMS: OBJECTIVE:Mutations in the α-synuclein-encoding gene SNCA are considered as a rare cause of Parkinson's disease (PD). Our objective was to examine the frequency of the SNCA point mutations among PD patients of Polish origin. METHODS:Detection of the known SNCA point mutations A30P (c.88G>C), E46K (c.136G>A) and A53T (c.157A>T) was performed either using the Sequenom MassArray iPLEX platform or by direct sequencing of the SNCA exons 2 and 3. As the two novel substitutions A18T (c.52G>A) and A29S (c.85G>T) were identified, their frequency in a control population of Polish origin was assessed and in silico analysis performed to investigate the potential impact on protein structure and function. RESULTS:We did not observe the previously reported point mutations in the SNCA gene in our 629 PD patients; however, two novel potentially pathogenic substitutions A18T and A29S were identified. Each variant was observed in a single patient presenting with a typical late-onset sporadic PD phenotype. Although neither variant was observed in control subjects and in silico protein analysis predicts a damaging effect for A18T and pA29S substitutions, the lack of family history brings into question the true pathogenicity of these rare variants. CONCLUSIONS:Larger population based studies are needed to determine the pathogenicity of the A18T and A29S substitutions. Our findings highlight the possible role of rare variants contributing to disease risk and may support further screening of the SNCA gene in sporadic PD patients from different populations.

背景与目标：

BACKGROUND & AIMS: :Alpha-synuclein is a lipid-binding protein expressed in neurons and oligodendrocytes which is increased in Parkinson's disease. We identified two putative liver X receptor (LXR) response elements in the human alpha-synuclein gene and used synthetic (TO901317, GW3695) and physiological (27-hydroxycholesterol) LXR activators to assess regulation of alpha-synuclein. LXR ligands upregulated alpha-synuclein mRNA by two-five-fold in human SK-N-SH neurons and three-six-fold in human MO3.13 oligodendrocytes. Significant 50% to four-fold induction of alpha-synuclein protein was also detected. Under these conditions, mRNA for LXR-responsive gene ABCA1 was significantly upregulated 15-40-fold and 5-25-fold in neurons and oligodendrocytes, respectively. LXR may, therefore, contribute to the regulation of alpha-synuclein expression in neurons and oligodendrocytes.

背景与目标： : α-突触核蛋白是一种在神经元和少突胶质细胞中表达的脂质结合蛋白，在帕金森氏病中会增加。我们在人类 α-突触核蛋白基因中鉴定了两个假定的肝X受体 (LXR) 反应元件，并使用合成 (TO901317，GW3695) 和生理 (27-羟基胆固醇) LXR激活剂来评估 α-突触核蛋白的调节。LXR配体将 α-突触核蛋白mRNA在人sk-n-sh神经元中上调了2-5倍，在人MO3.13少突胶质细胞中上调了3-6倍。还检测到对四倍 α-突触核蛋白诱导的显著50%。在这些条件下，LXR响应基因ABCA1的mRNA在神经元和少突胶质细胞中分别显着上调15-40倍和5-25倍。因此，LXR可能有助于调节神经元和少突胶质细胞中 α-突触核蛋白的表达。

BACKGROUND & AIMS: :Proteins implicated in neurodegenerative conditions such as Alzheimer's disease (AD) and Dementia with Lewy Bodies (DLB) have been identified in bodily fluids encased in extracellular vesicles called exosomes. Whether exosomes found in DLB patients can transmit pathology is not clear. In this study, exosomes were successfully harvested through ultracentrifugation from brain tissue from DLB and AD patients as well as non-diseased brain tissue. Exosomes extracted from brains diagnosed with either AD or DLB contained aggregate-prone proteins. Furthermore, injection of brain-derived exosomes from DLB patients into the brains of wild type mice induced α-synuclein (α-syn) aggregation. As assessed through immunofluorescent double labeling, α-syn aggregation was observed in MAP2+, Rab5+ neurons. Using a neuronal cell line, we also identified intracellular α-syn aggregation mediated by exosomes is dependent on recipient cell endocytosis. Together, these data suggest that exosomes from DLB patients are sufficient for seeding and propagating α-syn aggregation in vivo.

背景与目标： : 与神经退行性疾病 (例如阿尔茨海默氏病 (AD) 和路易体 (DLB) 痴呆) 有关的蛋白质已在包裹在称为外泌体的细胞外囊泡中的体液中鉴定。在DLB患者中发现的外泌体是否可以传播病理尚不清楚。在这项研究中，通过超速离心从DLB和AD患者的脑组织以及非患病脑组织中成功收获了外泌体。从诊断为AD或DLB的大脑中提取的外泌体含有易于聚集的蛋白质。此外，将DLB患者的脑源性外泌体注射到野生型小鼠的大脑中会诱导 α-突触核蛋白 (α-syn) 聚集。通过免疫荧光双重标记评估，在MAP2，Rab5神经元中观察到 α-syn聚集。使用神经元细胞系，我们还确定了由外泌体介导的细胞内 α-syn聚集取决于受体细胞内吞作用。总之，这些数据表明来自DLB患者的外来体足以在体内播种和传播 α-syn聚集。

BACKGROUND & AIMS: :Parkinson's disease (PD) is a common neurodegenerative condition affecting more than 8 million people worldwide. Although, the majority of PD cases are sporadic in nature, there are a growing number of monogenic mutations identified to cause PD in a highly penetrant manner. Many of these familial mutations give rise to a condition that is clinically and neuropathologically similar, if not identical, to sporadic PD. Mutations in genes such as SNCA cause PD in an autosomal dominant manner and patients have motor and non-motor symptoms that are typical for sporadic PD. With the advent of reprogramming technology it is now possible to capture these mutations in induced pluripotent stem cells (iPSCs) to establish models of PD in a dish. There are multiple neuronal subtypes affected in PD including the midbrain dopaminergic (mDA) neurons of the substantia nigra. Robust neuronal differentiation into mDA or other relevant neural cell types are critical to accurately model the disease and ensure the findings are relevant to understanding the disease process. Another challenge for establishing accurate models of PD is being met by the generation of isogenic control iPSC lines with precise correction of mutations using advanced gene editing technology. The contributions of ageing and environmental factors present further challenges to this field, but significant progress is being made in these areas to establish highly relevant and robust models of PD. These human neuronal models, used in conjunction with other model systems, will vastly improve our understanding of the early stages of the PD, which will be key to identifying disease-modifying and preventative treatments.

背景与目标： 帕金森氏病 (PD) 是一种常见的神经退行性疾病，影响着全世界800万多人。尽管大多数PD病例本质上是零星的，但越来越多的单基因突变被确定以高度渗透的方式引起PD。这些家族突变中的许多引起的疾病在临床和神经病理学上与散发性PD相似，即使不相同。诸如SNCA之类的基因突变以常染色体显性遗传方式引起PD，并且患者具有散发性PD典型的运动和非运动症状。随着重编程技术的出现，现在可以在诱导多能干细胞 (ipsc) 中捕获这些突变，以在培养皿中建立PD模型。PD中有多种神经元亚型，包括黑质的中脑多巴胺能 (mDA) 神经元。强大的神经元分化为mDA或其他相关的神经细胞类型对于准确建模疾病并确保发现与理解疾病过程相关至关重要。建立PD准确模型的另一个挑战是通过使用先进的基因编辑技术对突变进行精确校正的等基因对照iPSC系的产生来满足。老龄化和环境因素的贡献给该领域带来了进一步的挑战，但是在建立高度相关和可靠的PD模型方面，这些领域正在取得重大进展。这些人类神经元模型与其他模型系统结合使用，将极大地提高我们对PD早期阶段的理解，这将是识别疾病缓解和预防治疗的关键。

BACKGROUND & AIMS: :α-synuclein (αsyn) forms pathologic inclusions in several neurodegenerative diseases termed synucleinopathies. The inclusions are comprised of αsyn fibrils harboring prion-like properties. Prion-like activity of αsyn has been studied by intracerebral injection of fibrils into mice, where the presence of a species barrier requires the use of mouse αsyn. Post-translational modifications to αsyn such as carboxy (C)-terminal truncation occur in synucleinopathies, and their implications for prion-like aggregation and seeding are under investigation. Herein, C-truncated forms of αsyn found in human disease are recapitulated in mouse αsyn to study their seeding activity in vitro, in HEK293T cells, in neuronal-glial culture, and in nontransgenic mice. The results show that C-truncation of mouse αsyn accelerates aggregation of αsyn but alters prion-like seeding of inclusion formation.

背景与目标： : α-突触核蛋白 (α syn) 在几种称为突触核蛋白病的神经退行性疾病中形成病理性包涵体。内含物由具有朊病毒样特性的 α syn原纤维组成。通过向小鼠脑内注射原纤维研究了 α syn的朊病毒样活性，其中存在物种屏障需要使用小鼠 α syn。在突触核蛋白病中会发生对 α syn的翻译后修饰，例如羧基 (C) 末端截短，并且正在研究它们对朊病毒样聚集和播种的影响。在本文中，在人类疾病中发现的C-截短形式的 α syn在小鼠 α syn中进行了概括，以研究其在体外，HEK293T细胞，神经元神经胶质培养物和非转基因小鼠中的播种活性。结果表明，小鼠 α syn的C截短加速了 α syn的聚集，但改变了包裹体形成的类病毒种子。

BACKGROUND & AIMS: :The search for a biomarker for Parkinson's disease (PD) has led to a surge in literature describing peripheral α-synuclein (aSyn) in both biofluids and biopsy/autopsy tissues. Despite encouraging results, attempts to capitalize on this promise have fallen woefully short. The Systemic Synuclein Sampling Study (S4) is uniquely designed to identify a reproducible diagnostic and progression biomarker for PD. S4 will evaluate aSyn in multiple tissues and biofluids within the same subject and across the disease spectrum to identify the optimal biomarker source and provide vital information on the evolution of peripheral aSyn throughout the disease. Additionally, S4 will correlate the systemic aSyn profile with an objective measure of nigrostriatal dopaminergic function furthering our understanding of the pathophysiological progression of PD.

背景与目标： : 寻找帕金森氏病 (PD) 的生物标志物导致描述生物流体和活检/尸检组织中外周 α-突触核蛋白 (aSyn) 的文献激增。尽管取得了令人鼓舞的结果，但利用这一诺言的尝试却远远不够。系统性突触核蛋白采样研究 (S4) 的独特设计，以确定可重复的PD诊断和进展生物标志物。S4将评估同一受试者内和整个疾病谱中的多个组织和生物流体中的aSyn，以确定最佳生物标志物来源，并提供有关整个疾病中周围aSyn演变的重要信息。此外，S4将全身性aSyn谱与黑质纹状体多巴胺能功能的客观测量相关联，以进一步了解PD的病理生理进展。

BACKGROUND & AIMS: :Protein fibrils drive the onset and progression of many diseases in a prion-like manner, i.e. they transcellular propagate through the extracellular space to health cells to initiate toxic aggregation as seeds. The conversion of native α-synuclein into filamentous aggregates in Lewy bodies is a hallmark of Parkinson's disease (PD). Copper and iron ions accumulate in PD brains, however, whether they influence the prion-like propagation of α-synuclein remain unclear. Here, we reported that copper/iron ions accelerate prion-like propagation of α-synuclein fibrils by promoting cellular internalization of α-synuclein fibrils, intracellular α-synuclein aggregation and the subsequent release of mature fibrils to the extracellular space to induce further propagation. Mechanistically, copper/iron ions enhanced α-synuclein fibrils internalization was mediated by negatively charged membrane heparan sulfate proteoglycans (HSPGs). α-Synuclein fibrils formed in the presence of copper/iron ions were more cytotoxic, causing increased ROS production, cell apoptosis, and shortened the lifespan of a C. elegans PD model overexpressing human α-synuclein. Notably, these deleterious effects were ameliorated by two clinically used chelators, triethylenetetramine and deferiprone. Together, our results suggest a new role for heavy metal ions, e.g. copper and iron, in the pathogenesis of PD through accelerating prion-like propagation of α-synuclein fibrils.

背景与目标： : 蛋白质原纤维以类似朊病毒的方式驱动许多疾病的发生和发展，即它们通过细胞外空间跨细胞传播到健康细胞，以启动作为种子的毒性聚集。路易体中天然 α-突触核蛋白转化为丝状聚集体是帕金森氏病 (PD) 的标志。铜和铁离子在PD大脑中积累，但是，它们是否影响 α-突触核蛋白的朊病毒样传播尚不清楚。在这里，我们报道了铜/铁离子通过促进 α-突触核蛋白原纤维的细胞内在化，细胞内 α-突触核蛋白聚集以及随后成熟原纤维释放到细胞外空间以诱导进一步繁殖来加速 α-突触核蛋白原纤维的病毒样传播。从机理上讲，铜/铁离子增强了 α-突触核蛋白原纤维的内在化是由带负电的膜硫酸乙酰肝素蛋白聚糖 (hspg) 介导的。在铜/铁离子存在下形成的 α-突触核蛋白原纤维更具细胞毒性，导致ROS产生增加，细胞凋亡并缩短了过度表达人类 α-突触核蛋白的秀丽隐杆线虫PD模型的寿命。值得注意的是，两种临床使用的螯合剂三乙烯四胺和去铁酮改善了这些有害作用。总之，我们的结果表明，通过加速 α-突触核蛋白原纤维的朊病毒样传播，重金属离子 (例如铜和铁) 在PD的发病机理中起新作用。

BACKGROUND & AIMS: BACKGROUND:Abnormal α-synuclein aggregation and deposition is the pathological hallmark of Parkinson's disease (PD) and dementia with Lewy bodies (DLB), but is also found in Alzheimer disease (AD). Therefore, there is a gaining interest in α-synuclein in cerebrospinal fluid (CSF) as potential biomarker for these neurodegenerative diseases. To broaden the available choices of α-synuclein measurement in CSF, we developed and validated a new assay for detecting total α-synuclein. METHODS:This novel ELISA uses commercially available antibodies and is based on electrochemiluminescence technology. The assay protocol is straightforward, with short and simple incubation steps, and requires only small amounts of CSF. We validated this assay for precision, parallelism, dilution linearity, specificity, and spike recovery. We further compared it to the newly validated α-synuclein assay from BioLegend by analyzing a set of 50 CSF samples with both assays. RESULTS:The new assay quantifies α-synuclein in CSF with a lower limit of detection of 36.3 pg/mL and shows no cross-reactivity with human β- and γ-synuclein. Results of dilution linearity, parallelism, spike recovery, and precision classify this assay as well suited for α-synuclein detection in human CSF samples. CONCLUSIONS:We present a novel assay based on freely available components to quantify total α-synuclein in CSF as an additional method for α-synuclein as a biomarker in neurodegenerative diseases. The assay convinces with its simple and convenient protocol paired with high sensitivity.

背景与目标：

BACKGROUND & AIMS: :We recently reported that Alzheimer's disease (AD) with amygdala Lewy bodies (ALB) is a distinct form of alpha-synucleinopathy that occurs in advanced AD. In AD/ALB the alpha-synuclein pathology correlated with tau pathology, but not amyloid plaques, and there was often co-localization of tau and alpha-synuclein in the same neuron. Given the anatomical connectivity of the anterior olfactory nucleus and the amygdala, which receives axonal projections from the olfactory bulb, we hypothesized that there might be a relationship between tau and alpha-synuclein pathology in the olfactory bulb and the amygdala in AD. We screened for alpha-synuclein pathology in the olfactory bulb in AD with and without ALB, and investigated its relationship with tau pathology. In 38 of 41 (93%) AD/ALB cases and 4 of 21 (19%) AD cases without ALB (AD/non-ALB), alpha-synuclein pathology was detected in the olfactory bulb. Double immunolabeling at the light and electron microscopic levels revealed co-localization of tau and alpha-synuclein in the olfactory bulb neurons and neurites. The severity of tau pathology correlated with alpha-synuclein pathology in the olfactory bulb. In addition, alpha-synuclein pathology in the olfactory bulb correlated with alpha-synuclein pathology in amygdala. Tau pathology was greater in both the olfactory bulb and amygdala in AD/ALB than in AD/non-ALB, but there was no difference in tau pathology between the two groups in other brain regions assessed. The present study shows that in AD/ALB, the olfactory bulb is nearly equally vulnerable to tau and alpha-synuclein pathology as the amygdala and suggests that neurodegeneration in these two anatomical regions is linked.

背景与目标： : 我们最近报道了患有杏仁核路易体 (ALB) 的阿尔茨海默氏病 (AD) 是发生在晚期AD中的一种独特形式的 α 突触核蛋白病。在AD/ALB中，α-突触核蛋白病理与tau病理相关，但与淀粉样斑块无关，并且tau和 α-突触核蛋白经常在同一神经元中共同定位。考虑到前嗅神经核和杏仁核的解剖连接，杏仁核从嗅球接收轴突投射，我们假设嗅球和AD杏仁核中的tau和 α-突触核蛋白病理之间可能存在关系。我们在有或没有ALB的AD嗅球中筛选了 α-突触核蛋白病理学，并研究了其与tau病理学的关系。在41例 (93% 例) AD/ALB病例中的38例和无ALB (AD/非ALB) 的21例 (19% 例) AD病例中的4例中，在嗅球中检测到 α-突触核蛋白病理。光镜和电子显微镜下的双重免疫标记显示tau和 α-突触核蛋白在嗅球神经元和神经突中的共定位。tau病理的严重程度与嗅球中的 α-突触核蛋白病理相关。此外，嗅球中的 α-突触核蛋白病理与杏仁核中的 α-突触核蛋白病理相关。AD/ALB中嗅球和杏仁核的Tau病理学均高于AD/非ALB，但在评估的其他大脑区域中，两组之间的tau病理学没有差异。本研究表明，在AD/ALB中，嗅球与杏仁核几乎同样容易受到tau和 α-突触核蛋白病理学的影响，并表明这两个解剖区域的神经变性是相关的。

BACKGROUND & AIMS: :Parkinson's disease and some other neurodegenerative disorders are associated with a protein that can aggregate and form fibrils called alpha-synuclein. Like many other proteins associated with neurodegenerative disorders, this protein has no known function, and the mechanism by which it could cause diseases is poorly defined. It was recently suggested that it binds copper. This review assesses what is known about alpha-synuclein and its interaction with metals.

背景与目标： 帕金森氏病和其他一些神经退行性疾病与一种蛋白质有关，这种蛋白质可以聚集并形成称为 α-突触核蛋白的原纤维。与许多其他与神经退行性疾病相关的蛋白质一样，这种蛋白质没有已知的功能，并且它可能引起疾病的机制尚不明确。最近有人建议它结合铜。这篇评论评估了有关 α-突触核蛋白及其与金属相互作用的已知信息。

BACKGROUND & AIMS: :Alpha-synuclein is a major component of intraneuronal protein aggregates constituting a distinctive feature of Parkinson disease. To date, fluorescence imaging of dynamic processes leading to such amyloid deposits in living cells has not been feasible. To address this need, we generated a recombinant alpha-synuclein (alpha-synuclein-C4) bearing a tetracysteine target for fluorogenic biarsenical compounds. The biophysical, biochemical and aggregation properties of alpha-synuclein-C4 matched those of the wild-type protein in vitro and in living cells. We observed aggregation of alpha-synuclein-C4 transfected or microinjected into cells, particularly under oxidative stress conditions. Fluorescence resonance energy transfer (FRET) between FlAsH and ReAsH confirmed the close association of fibrillized alpha-synuclein-C4 molecules. Alpha-synuclein-C4 offers the means for directly probing amyloid formation and interactions of alpha-synuclein with other proteins in living cells, the response to cellular stress and screening drugs for Parkinson disease.

背景与目标： : α-突触核蛋白是构成帕金森病独特特征的神经内蛋白聚集体的主要成分。迄今为止，对导致活细胞中此类淀粉样蛋白沉积的动态过程进行荧光成像是不可行的。为了满足这一需求，我们产生了带有用于荧光二砷化合物的四半胱氨酸靶标的重组 α-突触核蛋白 (alpha-synuclein-C4)。alpha-synuclein-C4的生物物理，生化和聚集特性与体外和活细胞中的野生型蛋白质相匹配。我们观察到转染或微注入细胞的alpha-synuclein-C4聚集，特别是在氧化应激条件下。闪光和ReAsH之间的荧光共振能量转移 (FRET) 证实了纤化alpha-synuclein-C4分子的紧密结合。Alpha-synuclein-C4提供了直接探测活细胞中淀粉样蛋白的形成以及 α-突触核蛋白与其他蛋白质的相互作用，对细胞应激的反应以及筛选帕金森病药物的手段。

BACKGROUND & AIMS: :Although the function of biopolymer hydrogels in nature depends on structural anisotropy at mesoscopic length scales, the self-assembly of such anisotropic structures in vitro is challenging. Here we show that fibrils of the protein α-synuclein spontaneously self-assemble into structurally anisotropic hydrogel particles. While the fibrils in the interior of these supra-fibrillar aggregates (SFAs) are randomly oriented, the fibrils in the periphery prefer to cross neighboring fibrils at high angles. This difference in organization coincides with a significant difference in polarity of the environment in the central and peripheral parts of the SFA. We rationalize the structural anisotropy of SFAs in the light of the observation that αS fibrils bind a substantial amount of counterions. We propose that, with the progress of protein polymerization into fibrils, this binding of counterions changes the ionic environment which triggers a change in fibril organization resulting in anisotropy in the architecture of hydrogel particles.

背景与目标： : 尽管生物聚合物水凝胶在自然界中的功能取决于介观长度尺度上的结构各向异性，但这种各向异性结构在体外的自组装具有挑战性。在这里，我们显示蛋白质 α-突触核蛋白的原纤维自发自组装成结构各向异性的水凝胶颗粒。虽然这些超原纤维聚集体 (SFAs) 内部的原纤维是随机定向的，但外围的原纤维更喜欢以大角度交叉相邻的原纤维。组织上的这种差异与SFA中央和外围部分环境极性的显着差异相吻合。根据 α s原纤维结合大量抗衡离子的观察，我们合理化了SFAs的结构各向异性。我们建议，随着蛋白质聚合成原纤维的过程，抗衡离子的这种结合会改变离子环境，从而触发原纤维组织的变化，从而导致水凝胶颗粒结构的各向异性。