Mechanical properties of physiological and pathological models of collagen peptides investigated via steered molecular dynamics simulations
Mechanical properties of physiological and pathological models of collagen peptides investigated via steered molecular dynamics simulations
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DOI：
10.1016/j.jbiomech.2008.06.028
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发表时间：
2008-10-20
影响因子：
2.4
通讯作者：
Redaelli, Alberto
中科院分区：
文献类型：
--
作者：
Gautieri, Alfonso;Vesentini, Simone;Redaelli, Alberto
在这项工作中，我们使用分子模拟来研究胶原单链和三螺旋的弹性性质，目的是从第一性原理出发了解其特征。我们分析了理想的胶原肽、同三聚体和异三聚体的I型胶原以及胶原的病理模型。三螺旋结构比单链结构具有更强的刚性，从而揭示了疏水相互作用和氢键等链间稳定力的重要作用。对于理想的胶原模型和生理性三聚体，我们得到了接近4.5 GPA的杨氏模数，而生理性三聚体的杨氏模数为2.51 GPA，这可能与一种轻度的成骨不全有关，在这种情况下，只产生I型胶原的同源三聚体。此外，病理模型(以甘氨酸取代丙氨酸)显示的弹性模数为4.32 GPA，因此仅略低于理想模型。这表明，这种突变只会轻微影响胶原分子的机械性能，但可能会在更高的范围内发挥作用，例如胶原纤维的堆积。(C)2008爱思唯尔有限公司。保留所有权利。
In this work we used molecular simulations to investigate the elastic properties of collagen single chain and triple helix with the aim of understanding its features starting from first principles. We analysed ideal collagen peptides, homotrimeric and heterotrimeric collagen type I and pathological models of collagen. Triple helices were found much more rigid than single chains, thus enlightening the important role of interchain stabilizing forces, like hydrophobic interaction and hydrogen bonds. We obtained Young's moduli close to 4.5 GPa for the ideal model of collagen and for the physiological heterotrimer, while the physiological homotrimer presented a Young's modulus of 2.51 GPa, that can be related to a mild form of Osteogenesis Imperfecta in which only the homotrimeric form of collagen type I is produced. Otherwise, the pathological model (presenting a glycine to alanine substitution) showed an elastic modulus of 4.32 GPa, thus only slightly lower than the ideal model. This suggests that this mutation only slightly affects the mechanical properties of the collagen molecule, but possibly acts on an higher scale, such as the packing of collagen fibrils. (C) 2008 Elsevier Ltd. All rights reserved.