A Molecular Dynamics Investigation of Synthetic Collagen Thermal Properties

Composite biomaterials have been used for various medical applications as they contain specific physical, chemical and mechanical attributes while evading rejection by the body and encouraging proper function. One common material used for such function is collagen. As a triple helical, extracellular matrix (ECM) protein it constitutes approximately 25% of the total dry weight of mammals. The thermal properties of collagen can vary (320-370K) depending on the source, which impacts its physical properties, assembly, and stability. The social, physical, and financial expense of obtaining collagen, as its traditionally harvested from animals, has led to a need for synthetic collagen-like peptides. Synthetic collagen has a greater versatility due to their customizability, but a thorough investigation of their physical, and thermal properties as well as their binding capabilities must be completed prior to their production or use. This can be done by using computational modeling. In this study, we use molecular dynamics modeling to explore the structure and physics of synthetic collagen 1K6F in a solvent environment in response to thermal alterations. Simulations of 2 and 4 peptides showed a notable influence of structural orientation of the strands. Visual analysis of the simulations showed a interactions between the stands at low temperatures with some structural disturbance at after 330K. The radius of gyration (Rg) showed the backbone of the molecule start to fold over time around 20 ns. Further an exploration of the Radius of Fluctuation showed varying wave patterns with amplitudes between 1.5 and 7.5 nm. However, a sinusoidal behavior was noticeable at 320 and 330K indicating a possible transition point. The observed sinusoidal waveform in the atomic fluctuation can be ascribed to the thermal influences within the system. We found that a higher number of hydrogen bonds appear at low temperature as there was increased interactions below 320K, but the peptides appear to go to the process of denaturation as temperature increase to 340K. Furthermore, the assembly behavior and protein biding sites were analyzed through composite simulation of silk and collagen. Our results highlight that the interaction strength of synthetic collagen with silk depends on the proportion of collagen within the system.