Interrogating collagen mechanics at the single-molecule level

Collagen is the fundamental structural protein in vertebrates, forming a variety of hierarchical material structures. In spite of its prevalence and mechanical importance in biology, its mechanics at the molecular level – where it possesses a unique triple-helical structure – are surprisingly controversial: its flexibility is unresolved, as is its response to stress. My research group has been investigating these properties through single-molecule experiments. To do so, we have developed imaging algorithms to use in atomic-force microscopy (AFM), developed a model for polymers with inherent curvature (the curved worm-like chain model - cWLC), and built an instrument for high-throughput single-molecule force spectroscopy, the mini-radio centrifuge force microscope (MR.CFM). I’ll describe what we have learned about collagen’s flexibility and stress response, how local sequence context matters, and how our work resolves some of the many contentious findings regarding collagen’s mechanics.