title: Role of Ca(2+) for the mechanical properties of fibrillin.
abstract: Fibrillin-rich microfibrils are important structural elements widespread throughout connective tissues. Genetic defects identified in the Ca(2+) binding sites of fibrillin have severe effects and in addition Ca(2+) has a marked effect on the microfibrillar structure. We have studied the role of Ca(2+) on the mechanical behavior of fibrillin-rich microfibrils using the micro-needle technique. We find that Ca(2+)-depletion results in a 50% decrease in rest length and reduces the stiffness of fibrillin-rich microfibrils. At high strain, irreversible damage occurs. This behavior is consistent with Ca(2+) stabilization of interactions between consecutive EGF-like domains and breakdown in the quaternary structure upon over-extension.
authors.affiliation: Cardiff School of Biosciences, Connective Tissue Biology Laboratories, Cardiff University, Cardiff, United Kingdom. tie@kvl.dk
authors.forename: T A
authors.initials: TA
authors.lastname: Eriksen
authors.forename: D M
authors.initials: DM
authors.lastname: Wright
authors.forename: P P
authors.initials: PP
authors.lastname: Purslow
authors.forename: V C
authors.initials: VC
authors.lastname: Duance
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002417:Cattle; D004548:Elasticity; D000071837:Fibrillins; D020894:Microfibrils / Q000737:chemistry / Q000378:metabolism; D008840:Microfilament Proteins / Q000737:chemistry* / Q000378:metabolism*; D008845:Microinjections / Q000379:methods; D008958:Models, Molecular; D011480:Protease Inhibitors / Q000378:metabolism
chemical_list: D000071837:Fibrillins; D008840:Microfilament Proteins; D011480:Protease Inhibitors; D002118:Calcium