Vesentini Simone, Fitié Carel F C, Montevecchi Franco M, Redaelli Alberto
Department of Bioengineering, Politecnico di Milano, Via Golgi, 39, 20133, Milano, Italy.
Biomech Model Mechanobiol. 2005 Jun;3(4):224-34. doi: 10.1007/s10237-004-0064-5. Epub 2005 Apr 12.
Knowledge of the mechanical behavior of collagen molecules is critical for understanding the mechanical properties of collagen fibrils that constitute the main architectural building block of a number of connective tissues. In this study, the elastic properties of four different type I collagen 30-residue long molecular sequences, were studied by performing stretching simulations using the molecular mechanics approach. The energy-molecular length relationship was achieved by means of the geometry optimization procedure for collagen molecule strains up to 10%. The energy was interpolated by a second order function, and the second order of the derivative with respect to the mean length corresponded to the molecule stiffness. According to the hypothesis of linear elastic behavior, except for one sequence, the elastic modulus was around 2.40 GPa. These values are larger than fibril values, and they confirm the hypothesis that tendon mechanical properties are deeply related to tendon hierarchical structure. A possible explanation of the lowest values obtained for one sequence (1.33-1.53 GPa) is provided and discussed.
了解胶原蛋白分子的力学行为对于理解构成多种结缔组织主要结构基石的胶原纤维的力学特性至关重要。在本研究中，通过使用分子力学方法进行拉伸模拟，研究了四种不同的30个残基长的I型胶原蛋白分子序列的弹性特性。通过对高达10%的胶原分子应变进行几何优化程序，得到了能量-分子长度关系。能量通过二阶函数进行插值，相对于平均长度的二阶导数对应于分子刚度。根据线弹性行为假设，除了一个序列外，弹性模量约为2.40 GPa。这些值大于纤维的值，并且证实了肌腱力学特性与肌腱层次结构密切相关的假设。针对一个序列获得的最低值（1.33 - 1.53 GPa）给出并讨论了一种可能的解释。
