基于生物大分子模板构建荧光纳米探针用于金属离子与神经退行性疾病相关蛋白相互作用研究

Nowadays, neurodegenerative disease is the research focus and hotspot in the field of life sciences and clinical medicine. The interaction between metal ions and proteins plays an important role in the development and progression of neurodegenerative diseases. The goal of this project is to study the interaction between metal ions and protein related to neurodegenerative disease based on fluorescent nanoprobes. The fluorescent nanoprobes are prepared by biomineralization methods using proteins, peptides or other biomacromolecules as templates. Through further modification of reference fluorophores on the nanoprobe, ratiometric fluorescent probes are developed to sensitive and accurate detection of metal ions. Based on that, the binding sites of metal ions and proteins together with other dynamic characteristics such as the association rate constants and dissociation constants will be studied. Furthermore, by constructing fluorescent nanoprobes showing simultaneous responses to metal ions and reactive oxygen species, the role of proteins in influencing the production of reactive oxygen species originated from metal ions will be evaluated. Further study including the effects of metal ions on protein aggregation and cell viability will also be performed. On the basis of that, by screening ligands targeting metal ions, the mechanism of metal ions-induced protein aggregation will be elucidated. We hope the implementation of this project would provide theoretical and experimental basis for understanding the pathogenesis and treatment of neurodegenerative diseases.

神经退行性疾病是目前生命科学和临床医学领域研究的重点和热点，其中，金属离子与神经退行性疾病相关蛋白的相互作用在疾病的发生和发展过程中起着重要作用。本项目拟以金属离子与神经退行性疾病相关蛋白的相互作用为研究目标，基于生物矿化等仿生方法，以蛋白、多肽等生物大分子作为金属纳米簇合成的模板，构建对金属离子具有灵敏响应的有机-无机杂化荧光纳米探针，通过在探针表面修饰内参荧光分子以制备比率型荧光探针，研究金属离子与疾病相关蛋白相互作用的结合位点、反应速率常数、结合常数等动力学特征。在此基础上，制备对金属离子和活性氧同时响应的荧光纳米探针，利用探针对金属离子以及金属离子与蛋白复合物催化产生活性氧的检测，研究金属离子对蛋白聚集过程以及细胞氧化损伤的影响；阐明金属离子配位剂对金属离子细胞毒性的影响及其作用机制，为更加深刻理解神经退行性疾病的发病机理和疾病治疗提供理论和实验依据。

本项目合成了金属离子如铜离子、锌离子等响应的多个荧光探针，然后以两亲性磷脂聚合物组装的纳米粒、短肽组装的纳米带等为载体，负载荧光探针，同时在纳米材料表面修饰内参荧光分子制备比率型荧光纳米探针，发展了金属离子灵敏检测方法，研究金属离子对细胞氧化损伤的影响，阐明金属离子配位剂对金属离子诱导细胞毒性的影响；通过在短肽上修饰与淀粉样蛋白Aβ特异性相互作用的唾液酸，将其组装成纳米线，构建Aβ灵敏响应的荧光探针，研究了铜离子与Aβ的相互作用；合成多肽修饰的多功能聚合物，制备对Aβ和活性氧同时响应的纳米探针，结果表明多功能探针在消除金属离子与Aβ相互作用产生的活性氧以及抑制Aβ聚集方面具有潜力。该项目为更加深刻理解神经退行性疾病的发病机理和发展疾病相关诊疗策略提供了依据。