title: Stretching type II collagen with optical tweezers.
abstract: Collagens are the most abundant proteins of vertebrates and they provide mechanical and supportive functions in a wide range of connective tissues. Knowledge of the mechanical properties of single collagen molecules is essential in studying the self-assembly of collagen, the interaction between cells and extracellular matrix, the etiology of tissue degeneration and mechanism of regeneration, and the relationship between the structures and mechanical properties of tissues. Here we stretched single type II collagen molecules in neutral pH solution using optical tweezers. The molecular parameters of collagen were obtained by fitting force-extension curves into worm-like chain elasticity model. The molecule length of type II collagen monomer was 295.8 nm. The persistence length of type II collagen monomer was 11.2 nm. These observations indicate that collagen molecules are flexible rather than rigid rod molecules at neutral pH solution.
authors.affiliation: Department of Orthopedic Surgery, Biomechanics Laboratory, Mayo Clinic Rochester, 200 First Street SW, 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: D024043:Collagen Type II / Q000737:chemistry*; D004548:Elasticity; D055095:Optics and Photonics / Q000295:instrumentation*; D011994:Recombinant Proteins / Q000737:chemistry
chemical_list: D024043:Collagen Type II; D011994:Recombinant Proteins