title: Direct quantification of the flexibility of type I collagen monomer.
abstract: Collagens are the most abundant structural proteins found in the extracellular matrix of vertebrates. Knowledge of the mechanical behavior of collagen monomers is essential for understanding the mechanical properties of collagen fibrils that constitute the main architectural framework of skin, bone, cartilage, and other connective tissues. In this study, the flexibility of type I collagen monomer was studied by stretching type I collagen monomers directly. The force-extension relationship was measured and analyzed by fitting the data into a worm-like chain elasticity model. The persistence length of collagen I monomer was determined to be 14.5 nm and the contour length was 309 nm. The results confirm that type I collagen monomer is flexible rather than rigid, rod-like molecule. Such flexibility may possibly be a consequence of the micro-unfolding of discrete domains of single collagen molecule.
authors.affiliation: Biomechanics Laboratory, Department of Orthopedic Surgery, Mayo Clinic/Mayo Foundation, Rochester, MN 55905, USA.
authors.forename: Yu-Long
authors.initials: YL
authors.lastname: Sun
authors.forename: Zong-Ping
authors.initials: ZP
authors.lastname: Luo
authors.forename: Andrzej
authors.initials: A
authors.lastname: Fertala
authors.forename: Kai-Nan
authors.initials: KN
authors.lastname: An
mesh_terms: D024042:Collagen Type I / Q000737:chemistry*; D006801:Humans; D036103:Nanotechnology; D011487:Protein Conformation
chemical_list: D024042:Collagen Type I