- 學位論文
以分子動力模擬探討膠原蛋白組織中交聯鍵的分佈對膠原纖維機械行為和結構特性的影響
The influence of crosslink on the mechanical and structural properties of collagen fibril in tissues: A molecular dynamics approach
摘要
第一型膠原蛋白是人體中一種重要的蛋白質，它構成人體中很多重要的組織，像是骨頭，軟骨，肌腱和韌帶等。在組織中，第一型膠原蛋白透過分子間的交聯鍵連接，來改變組織的物理性質。一般而言，膠原蛋白組織的強度會隨著交聯密度的提升而增加，並且增加其組織的勁度。先前的研究證實了老化現象和交聯的密度有正向的關係。除此之外，在實驗上發現非酵素所形成的交聯和一些疾病有關，如糖尿病。 在本研究中，藉由膠原蛋白纖維的全原子模型進行模擬及分析，著重在纖維、分子結構特徵以及降解區域特性。膠原蛋白纖維的overlap 和 gap的分佈可以分析滑動與變形機制，膠原蛋白分子的unit height 和 radius來分析分子的結構以及變形的機制。本研究提供膠原蛋白分子的變形機制，可以更深入了解組織老化在纖維尺度下的表現。
並列摘要
Type I collagen is one of important proteins in the human body. It is rich in human tissues such as bone, cartilage, tendon, ligament, which gives crucial support in human tissues. In tissues, type I collagen molecules form linkage by “Crosslinks”, which utilize covalent bonds to form. Moreover, it can change the physical properties of tissues. In general, tissues can be strengthened with increasing density of cross-links within collagen, which would further higher the stiffness of tissues. However, previous studies have indicated that is a positive correlation between exceeding cross-links’ density and aging problem. In addition, abundant amounts of Crosslinks within non-enzyme structures in tissues were discovered to induce fatal diseases, such as diabetes. In this study, we focus on structural characteristics of collagen and biological function in fibril through full atomic approach. To analyze the deforming and sliding mechanism of collagen, we analyzed the distribution of overlap and gap within collagen fibril. We further studied the unit height and radius of collagen molecule to understand its structural characteristics and deformation mechanism. Our results provided fundamental insights into the molecular mechanism of collagen, which further give possible explanation of tissue aging.