トロポコラーゲンと架橋構造の全原子MDモデリングおよび力学特性のシミュレーション

抄録

Collagen is known as a protein which exists in bodies of all animal species and nowadays it will be tried to apply to a novel material for medical devices. It is necessary to understand the strength of collagen to improve the performance and usability of the devices. The basic unit of collagen is called tropocollagen, and it has a rod shape with nano-meter size and contains characteristic triple helical structures. This is indeed too small scale to evaluate experimentally, so modeling and computer simulation by using molecular dynamics are effective to study it. There are many cross-linked structures between tropocollagen molecules, which are considered to largely affect its mechanical properties including strength and ductility. In this study, an all-tom model for computation is constructed in which three tropocollagen molecules are arranged in parallel together with some imaginary cross-linking molecules. The simulation of tensile test is conducted by pulling one of molecules using SMD method, in order to investigate the effect of cross-linking molecule in deformation process. As a result, it is confirmed that the model with cross-linking molecules requires more load than that without them until they take off tropocollagen molecule. In this study, it is found that cross-linking molecules play a microscopic and great role in increasing the strength of collagen.