固有无规结构蛋白片段占细胞总蛋白量的30%，许多重要无规结构蛋白在生物体内发挥着重要作用。但是无规结构蛋白的功能通过什么方式行使至今是个难题，而固有无规结构的构象分析是当今生物物理研究的挑战。本课题基于申请人多年顺磁核磁共振的研究基础，特别是顺磁标记策略的建立和发展，提出解析固有无规结构蛋白构象的新思路。首先在固有无规结构上融合一个具有规则结构的小蛋白，而在小蛋白上引入顺磁探针，然后根据小蛋白的空间取向定出无规多肽链的构象。本课题主要以具有重要生理功能的alpha突触核蛋白为目标分子，在其上融合一个稳定结构的小模式蛋白，利用顺磁标记方式阐述突触核蛋白的构象。通过优化小分子模式蛋白与目标分子的融合体，在模式蛋白上引入顺磁探针、优化探针，根据所测量的顺磁信息分析突触核蛋白在溶液、拥挤环境和寡聚态下的构象变化，以对其功能有更深刻的了解。通过此课题的开展，建立一套分析固有无规结构蛋白的新方法。

More than 30% of eukaryotic proteins contain intrinsically disordered proteins (IDPs)(> 30 amino acids), and most of the IDPs play important roles in cellular processes. However, how the IDPs accomplishing their unique functions remains unclear and how to characterize the conformation exchange of the natively unstructured polypeptide at atomic resolution is still a challenge. This project relies on the applicant's expertise on site-specific labeling of proteins with paramagnetic lanthanide ions, which has been a powerful technique in achieving valuable long-range structural restraints of polypeptides. In this project, we focus on alpha-synuclein as the target protein and extensively study the conformation exchange of alpha-synuclein in solution and its oligomeric states by means of paramagnetic NMR spectroscopy. Fusion a well-structured model protein into alpha-synuclein will be made first and paramagnetic tagging the model protein will be applied subsequently. The determined paramagnetic center in the model protein permits the localization of unstructured polypeptide with respect to the well-structured fold. These new tools will become mainstream in characterizing the conformation exchange of IDPs in structural biology, which fulfills the physiological functions.