RUI: Determination of the orientation of 13C labeled specific residues of alpha-synuclein(61-95) in the pore structure formed on supported phospholipids bilayer by IRRAS

中田纳西州立大学化学系的王成山教授，在化学系化学结构、动力学机制B项目的资助下，研究了人类大脑中大量存在的与帕金森氏症有关的α-突触核蛋白的聚集体结构。 α-突触核蛋白形成两种类型的聚集体：成熟原纤维和寡聚体。 已知成熟的原纤维是无毒的，但寡聚体可通过在细胞膜中形成孔结构而导致神经元细胞死亡。 了解寡聚体聚集体的结构应该为帕金森病治疗剂的开发提供线索。 从事该项目的本科生和研究生包括第一代和代表性不足的少数民族学生，他们正在学习可能影响他们职业选择的研究领域。 此外，一个新的实验室实验肽合成的研究生水平的有机化学类正在开发。 已经开发了各种技术来确定蛋白质的结构。 其中，傅里叶变换红外光谱（FTIR）提供了快速的响应，并已被用于评估蛋白质和肽的各种构象（如α-螺旋，β-折叠，非结构化构象）。 该方法利用酰胺I带，其产生于骨架酰胺键中羰基的拉伸模式。 传统的傅里叶变换红外光谱只能提供构象的总体分数信息。 为了扩展其能力，可以将13 C标记引入骨架酰胺键中的羰基，并且可以产生新的条带（13 C酰胺I条带）以确定特定残基的构象。 本研究将13 C标记引入到α-突触核蛋白的序列中，在残基水平上研究α-突触核蛋白寡聚体的构象。 此外，红外反射-吸收光谱用于解决13 C标记羰基的取向。 利用构象和取向信息，可以在磷脂双层结构中评估α-突触核蛋白的结构。

In this project funded by the Chemical Structure, Dynamics & Mechanism B Program of the Chemistry Division, Professor Chengshan Wang of the Chemistry Department at Middle Tennessee State University is studying the structure of aggregates of a protein, alpha-synuclein, that is abundant in the human brain and that has been linked to Parkinson's disease. Alpha-synuclein forms two types of aggregates: mature fibrils and oligomers. The mature fibrils are known to be non-toxic, but oligomers can cause the death of the neuronal cells by forming pore structure in the cell membrane. Understanding the structure of oligomer aggregates should provide clues for the development of therapeutic agents for Parkinson's disease. Undergraduate and graduate students working on this project include first-generation and underrepresented minority students who are learning about research areas that could influence their career choices. In addition, a new laboratory experiment on peptide synthesis for a graduate level organic chemistry class is being developed. Various techniques have been developed to determine the structure of proteins. Among them, Fourier transform infrared spectroscopy (FTIR) provides a fast response and has been used to evaluate various conformations (such as alpha-helix, beta-sheet, unstructured conformation) in proteins and peptides. This method utilizes the amide I band, which arises from the stretching mode of the carbonyl group in the backbone amide bonds. Traditional FTIR can only provide information about an overall fraction of the conformations. To expand its capability, 13C labels can be introduced to the carbonyls in the backbone amide bonds and a new band (the 13C amide I band) can be generated to determine the conformation of specific residues. In this project, 13C labels are introduced into the sequence of alpha-synuclein to study the conformation of the oligomers of alpha-synuclein at the residue level. In addition, Infrared Reflection-Absorption Spectroscopy is used to address the orientation of 13C labeled carbonyls. With both conformation and orientation information, the structure of alpha-synuclein can be evaluated in phospholipid bilayer structures.