Author:
Roth Jonathan Andrew,Hoop Cody,Williams Jonathan,Hayes Robert,Baum Jean
Abstract
Collagen fibrils serve as the molecular scaffolding for connective tissues throughout the human body and are the most abundant protein building blocks in the extracellular matrix (ECM). Glycosaminoglycans (GAGs) are an important class of polysaccharides in the ECM that mediate collagen fibril development, cell adhesion and motility, wound healing, inter alia. Depletion or mis-regulation of GAGs has been shown to be intimately related to diseases such as cancer, hyperglycemia, and glaucoma and is often associated with changes to the mechanical properties of the ECM. However, the molecular-level impact of GAGs on ECM mechanobiology is not understood. Here, high resolution atomic force microscopy is used to assess perturbations to nanoscale topography and mechanical properties of single collagen fibrils upon GAG depletion in aqueous solution. Atomic force microscopy fast force mapping shows that GAG depletion reduces the contact stiffness of individual fibrils, lowering the indentation modulus by half compared to native fibrils, while retaining D-banding, a key structural motif. These results shed new light on the functional role of GAGs and may aid in strategies to treat diseases that impair ECM mechanobiology.
Publisher
Cold Spring Harbor Laboratory