A new molecular model for collagen elasticity based on synchrotron x-ray scattering evidence
A new molecular model for collagen elasticity based on synchrotron x-ray scattering evidence
复制标题
DOI：
10.1016/s0006-3495(97)78783-6
复制
发表时间：
1997-03-01
影响因子：
3.4
通讯作者：
Fratzl, P
中科院分区：
文献类型：
--
作者：
Misof, K;Rapp, G;Fratzl, P
胶原蛋白是脊椎动物中含量最丰富的结构蛋白。其应力-应变曲线的特定形状对许多器官的功能至关重要。尽管胶原蛋白的宏观力学行为已为人们所熟知，但在超分子水平上对其弹性过程的解释尚无定论。我们进行了原位同步加速器X射线散射实验，结果表明，随着胶原纤维的拉伸，侧向分子有序量增加。在应变循环实验中，应变与弥散赤道散射的关系在应力-应变曲线的“跟部”区域呈线性关系。提出了一种新的胶原蛋白弹性分子模型，该模型基于热激活分子扭结的存在，再现了这种线性关系，并对胶原蛋白的应力-应变曲线的形成给出了简单的解释。
Collagen is the most abundant structural protein in vertebrates. The specific shape of its stress-strain curve is crucial for the function of a number of organs. Although the macroscopic mechanical behavior of collagen is well known, there is still no explanation of the elastic process at the supramolecular level. We have performed in situ synchrotron x-ray scattering experiments, which show that the amount of lateral molecular order increases upon stretching of collagen fibers. In strain cycling experiments the relation between strain and diffuse equatorial scattering was found to be linear in the ''heel'' region of the stress-strain curve. A new molecular model for collagen elasticity is proposed, which, based on the existence of thermally activated molecular kinks, reproduces this linearity and gives a simple explanation for the form of the stress-strain curve of collagen.