title: Raman microscopy and X-ray diffraction, a combined study of fibrillin-rich microfibrillar elasticity.
abstract: Fibrillin-rich microfibrils are essential elastic structures contained within the extracellular matrix of a wide variety of connective tissues. Microfibrils are characterized as beaded filamentous structures with a variable axial periodicity (average 56 nm in the untensioned state); however, the basis of their elasticity remains unknown. This study used a combination of small angle x-ray scattering and Raman microscopy to investigate further the packing of microfibrils within the intact tissue and to determine the role of molecular reorganization in the elasticity of these microfibrils. The application of relatively small strains produced no overall change in either molecular or macromolecular microfibrillar structure. In contrast, the application of larger tissue extensions (up to 150%) resulted in a markedly different structure, as observed by both Raman microscopy and small angle x-ray scattering. These changes occurred at different levels of architecture and are interpreted as ranging from alterations in peptide bond conformation to domain rearrangement. This study demonstrates the importance of molecular elasticity in the mechanical properties of fibrillin-rich microfibrils in the intact tissue.
authors.affiliation: Department of Biological Sciences, University of Stirling, Stirling FK9 4LA, United Kingdom. j.l.haston@stir.ac.uk
authors.forename: J Louise
authors.initials: JL
authors.lastname: Haston
authors.forename: Soren B
authors.initials: SB
authors.lastname: Engelsen
authors.forename: Manfred
authors.initials: M
authors.lastname: Roessle
authors.forename: John
authors.initials: J
authors.lastname: Clarkson
authors.forename: Ewan W
authors.initials: EW
authors.lastname: Blanch
authors.forename: Clair
authors.initials: C
authors.lastname: Baldock
authors.forename: Cay M
authors.initials: CM
authors.lastname: Kielty
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Wess
mesh_terms: D000818:Animals; D004548:Elasticity; D000071837:Fibrillins; D020894:Microfibrils / Q000378:metabolism*; D008840:Microfilament Proteins / Q000737:chemistry*; D008958:Models, Molecular; D011487:Protein Conformation; D012756:Sheep; D013059:Spectrum Analysis, Raman / Q000379:methods; D014961:X-Ray Diffraction / Q000379:methods
chemical_list: D000071837:Fibrillins; D008840:Microfilament Proteins