基于蛋白质可控解折叠与聚集策略的水下生物胶

Underwater bio-glue have a promising future in the field of industry and biomedicine. However, existing underwater bio-adhesive systems suffer drawbacks such as complicated preparation steps, low bonding strength, difficulty in permanent adhesion, and toxic. Different from the current systems, this study intends to construct a universal strategy to transform proteins into underwater bio-glue by flexibly regulating the process of amyloid protein self-assembly. The main contents are as follows: 1. The kinetic of amyloid self-assembly is studied firstly. The relationship between the structure and adhesion ability of amyloid and the protein unfolding rate is revealed. The protein unfolding and amyloid self-assembly process are separated by adjusting the kinetic balance of protein unfolding and amyloid self-assembly. 2. The internal structure and adhesion properties of amyloid-like protein are optimized by regulating the unfolding and self-assembly rate of amyloid protein. And the intrinsic relationship between protein amyloid transformation and underwater adhesion behavior is explored. As a result, a new strategy for preparing underwater bio-glue with fast response, strong adhesion and long-term stability is developed. 3. The wound adhesion and hemostasis effect are verified to explore its application in biomedicine. This study will provide experimental and theoretical basis for the development of amyloid-based adhesion systems.

水下生物胶在工业和生物医学领域具有广阔的应用前景，然而现有体系存在制备方法复杂、粘附强度低、难以持久粘附、具有毒副作用等不足。与已报道的水下生物胶体系不同，本研究旨在通过灵活调节淀粉样蛋白的自组装过程，构建一种可将蛋白质转化为水下生物胶的普适性策略。主要研究内容包括：1、研究蛋白质淀粉样自组装的动力学过程，揭示淀粉样蛋白内部结构及粘附能力与蛋白质解折叠速率的关系，通过蛋白质的解折叠与淀粉样自组装的动态平衡控制，实现蛋白质解折叠与淀粉样组装过程的完全分离；2、通过调控蛋白质的解折叠与自组装速率，优化淀粉样蛋白的内部结构以及粘附性能，探索蛋白质淀粉样转变与水下粘附行为的内在联系，发展一种可制备快速响应、粘附能力强、长久稳定的水下生物胶的新策略；3、验证该水下生物胶的伤口粘合以及止血功能，探索其在生物医学领域的应用。该研究可为淀粉样蛋白水下生物胶体系的研发提供实验基础与理论依据。

各类生物分泌的水下黏附蛋白为水下生物胶的开发提供了重要思路。然而，除了一些成本很高的特定粘附蛋白质，常见普通蛋白质难以直接用作水下胶水。在本研究中，我们证明解折叠的普通蛋白能够通过类淀粉样聚集，实现水下粘附。结合分子模拟与实验验证，提出了利用二硫键还原剂以及解折叠剂来获得稳定解折叠蛋白质的方法。对近20种解折叠蛋白质的水下粘附行为进行了归纳总结，得出了氨基酸配对序列占比需高于~16.77%这一重要结论。发现了蛋白质链中柔性疏水链对界面结合水的“钉扎”效应。结合有限元分析以及界面基团与内部结构解析，证明稳定剂扩散可导致蛋白质发生类淀粉样聚集，且这类型聚集为蛋白质水下胶提供了卓越的界面粘附与本体强度。最终，我们以牛血清白蛋白(BSA)为模型蛋白，制备出了强而稳定的蛋白质水下胶水，并实现各种体内外应用的初探。这一不依赖于任何特定基团的，构象重排介导的水下粘附策略，为开发新型水下粘合剂提供了另一条思路。