2020-01-012024-05-13https://scholars.lib.ntu.edu.tw/handle/123456789/650634摘要：角質細胞蛋白分子，是一種含disulfide bonds 的intermediate filament (IF)，也是最 常見的IF蛋白分子，是組成脊椎動物的頭髮、指甲和皮膚的關鍵材料之一。角質細 胞蛋白可進一步分為trichocyte hard keratin 及 epithelial keratin。Hard keratin 比 其他生物材料具有較優越的楊氏模數與硬度的力學性質，而epithelial keratin具有 較大的延展性。目前此領域仍較缺乏由基礎building blocks出發，以及對各個尺度 以及尺度間相關聯的機制探討之研究與技術。若能完整了解生物材料如何透過基礎 蛋白組成以及複雜層次結構提供獨特的材料穩定性、強度及可變性的能力，從生物 微觀分子組成以及材料性質之機制著手，深入探討研究從材料在原子尺度的基本組 成、結構排列與材料性質之連結，將對生物材料設計等相關領域會是一大重要進展 。本計畫將著重發展bottom-up 方式，由角質蛋白質序列開始建立角質蛋白原子尺 度結構，研究角質蛋白分子材料在不同環境中的多尺度材料特性和行為，通過一系 列的模擬和數值分析，將提供材料力學性質與結構耦合機制，並作為生物醫學和工 程應用設計新材料方向與新的範例，開發生物界面、仿生和生物啟發材料 。<br> Abstract: Keratin, one kind of intermediate filament, is the key component of hair, nail and skin in vertebrates, including mammals. Due to the various mechanical properties, keratin proteins can be further divided into two groups: trichocyte hard keratin and epithelial keratin. Trichocyte hard keratin has relatively higher modulus and toughness than other biological materials, and epithelial keratin has larger extensibility. The relationship between the hierarchical structure, the sequence of amino acids and the material properties still remain unclear. Now, with new computational power, novel electronic devices, and the breakthrough of computational algorithms, the field of computational modeling provide great opportunities for us to investigate the recipe to design new materials with complex hierarchical structures and innovative materials with advanced functions. In this project, we will develop a bottom-up approach to investigate the relationships of structure, behaviors and properties of the biological materials in different environments at multi-scales. This project will focus on investigating trichocyte keratin and epithelial keratin, which have distinct material properties, including high strength, high modulus, high extensibility and mutability. We will construct the full atomistic models of epithelial (soft) keratin molecule and microfibril to investigate its material properties, especially the high extensibility, in different length scales and how the behavior changes in different environments. Hard keratin proteins will be studied in this project to understand how mutable disulfide bonds affect their microscopic, mesoscopic and macroscopic level properties of materials and contribute the materials’ high modulus and strength. Using molecular dynamics simulations, we will provide insights into the mechanisms of chemical bonds in materials and illustrate the importance of the environment which affects the mechanical mechanisms and locations. Our study could be applied and extended to engineering materials or biomaterials, and could perhaps explain the mechanical behavior in these materials. The insight could be applied to designing the nanoscale structure of engineering and other materials consisting of the different bonds to achieve desired mechanical properties, and in particular strength, robustness and the ability to feature highly dissipative deformation behaviors. Possible applications range from the design of novel composites, fibre materials, to smart materials applied in nanotechnology, and micro-devices.多尺度模擬角質蛋白生物力學Molecular mechanismepithelial keratintrichocyte keratinmultiscale modeling