Following an introduction to relevant
length scales of biological systems, I’ll focus on the nanoscale world of
proteins. Collagen is the fundamental structural protein in vertebrates and is
widely used as biomaterial. In spite of its prevalence and mechanical
importance in biology, the mechanics of its 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, described models for polymers with inherent
curvature, and built a new 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, why these properties are important,
and how our work resolves some of the many contentious findings regarding
collagen’s mechanics.