Department of Chemistry and Biochemistry, University of California, Santa Cruz, California, USA.
J Biomol Struct Dyn. 2012;29(4):825-42. doi: 10.1080/073911012010525023.
Heavy metals have been implicated as the causative agents for the pathogenesis of the most prevalent neurodegenerative disease. Various mechanisms have been proposed to explain the toxic effects of metals ranging from metal-induced oxidation of protein to metal-induced changes in the protein conformation. Aggregation of a-synuclein is implicated in Parkinson's disease (PD), and various metals, including copper, constitute a prominent group of alpha-synuclein aggregation enhancers. In this study, we have systematically characterized the a-synuclein-Cu21 binding sites and analyzed the possible role of metal binding in a-synuclein fibrillation using a set of biophysical techniques, such as electron paramagnetic resonance (EPR), electron spin-echo envelope modulation (ESEEM), circular dichroism (CD), and size exclusion chromatography (SEC). Our analyses indicated that a-synuclein possesses at least two binding sites for Cu21. We have been able to locate one of the binding sites in the N-terminal region. Furthermore, based on the EPR studies of model peptides and Beta-synuclein, we concluded that the suspected His residue did not appear to participate in strong Cu21 binding.
重金属被认为是最常见的神经退行性疾病发病机制的致病因子。已经提出了各种机制来解释金属的毒性作用，从金属诱导的蛋白质氧化到金属诱导的蛋白质构象变化。α-突触核蛋白的聚集与帕金森病（PD）有关，包括铜在内的各种金属构成了α-突触核蛋白聚集增强剂的重要群体。在这项研究中，我们使用一系列生物物理技术，如电子顺磁共振（EPR）、电子自旋回波包络调制（ESEEM）、圆二色性（CD）和尺寸排阻色谱（SEC），系统地表征了α-突触核蛋白-Cu21 结合位点，并分析了金属结合在α-突触核蛋白纤维形成中的可能作用。我们的分析表明，α-突触核蛋白至少有两个结合 Cu21 的位点。我们已经能够在 N 端区域定位其中一个结合位点。此外，基于模型肽和β-突触核蛋白的 EPR 研究，我们得出结论，怀疑的组氨酸残基似乎没有参与强 Cu21 结合。
