Mechanical Behavior of Collagen Mimetic Peptides under Fraying Deformation via Molecular Dynamics

Collagen is a pervasive, triple helical, extracellular matrix (ECM) protein, found in human body from skin and bones to blood vessels and lungs, making it biocompatible, biodegradable, capable of cell attachment, and relevant for applications in bio-polymers, tissue engineering and a plethora of other bio-medical fields. Natural collagen’s extraction from natural sources is time consuming, sometimes costly, and it is also is difficult to render, and could present undesired biological and pathogenic changes. Nanoscale collagen mimetic peptides (Synthetic Collagen), without the unwanted biological entities present in the medium, has shown to mimic the unique properties that are present in natural collagen. Synthetic collagen, thus provides a superior alternative compared to natural collagen for its utilization in a plethora of several applications. Their properties are affected by surrounding environments, including various solvents, and can be tailored toward specific applications. The focus of this paper is to investigate the mechanical properties of these nanoscale collagen mimetic peptides with lengths of about 10nm, leading to understanding of their feasibility in bio-printing of a composite polymeric collagen biomaterial with a blend of multiple synthetic collagen molecules. Molecular dynamics modeling is used to simulate, model and analyze mechanical properties of synthetic collagen peptides. In particular, mechanical behavior of these peptides are studied via molecular dynamics modeling. An in-depth insight into the deformation and structural properties of the collagen peptides are of innovative significance for a multitude of bio medical engineering applications. Present paper employed steered molecular dynamics as the principal method of investigating the mechanical properties of nanoscale collagen mimetic peptide 1BKV, which closely resembles natural collagen with a shorter sequence length of 30 amino acids. Contrasts between the synthetic collagen proteins used for this work and natural Type I collagen stems from the length of the proteins, due to the number of amino-acids in the peptide chains. While natural Type I collagen has a sequence length of 341 amino-acids, the synthetic collagen protein 1BKV only has a length of 30 amino-acids. A detailed comprehension of the protein’s mechanical properties is investigated through fraying deformation behavior studied. Fraying behavior, the unwinding/separation of individual peptide chains from the triple helical structure is compared to the deformation behavior of the protein, where the protein is subjected to tensile force until complete failure of the structure. A calculated Gibbs free energy value of 40 Kcal/mol corresponds with a complete unfolding of a single alpha-helix peptide chain from a triple helical protein in case of fraying. Force needed for complete separation of the alpha-helix from the triple-helical protein is analyzed, and discussed in this paper.