title: Persistence and variation in microstructural design during the evolution of spider silk.
abstract: The extraordinary mechanical performance of spider dragline silk is explained by its highly ordered microstructure and results from the sequences of its constituent proteins. This optimized microstructural organization simultaneously achieves high tensile strength and strain at breaking by taking advantage of weak molecular interactions. However, elucidating how the original design evolved over the 400 million year history of spider silk, and identifying the basic relationships between microstructural details and performance have proven difficult tasks. Here we show that the analysis of maximum supercontracted single spider silk fibers using X ray diffraction shows a complex picture of silk evolution where some key microstructural features are conserved phylogenetically while others show substantial variation even among closely related species. This new understanding helps elucidate which microstructural features need to be copied in order to produce the next generation of biomimetic silk fibers.
authors.affiliation: Centro de Tecnología Biomédica. Universidad Politécnica de Madrid. 28223 Pozuelo de Alarcón (Madrid), Spain.|Departamento de Ciencia de Materiales. ETSI Caminos, Canales y Puertos. Universidad Politécnica de Madrid, 28040 Madrid, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Madurga
authors.affiliation: Department of Biology and Integrated Bioscience Program. The University of Akron, Akron, OH44325-3908, USA.
authors.forename: T A
authors.initials: TA
authors.lastname: Blackledge
authors.affiliation: Centro de Tecnología Biomédica. Universidad Politécnica de Madrid. 28223 Pozuelo de Alarcón (Madrid), Spain.|Departamento de Ciencia de Materiales. ETSI Caminos, Canales y Puertos. Universidad Politécnica de Madrid, 28040 Madrid, Spain.
authors.forename: B
authors.initials: B
authors.lastname: Perea
authors.affiliation: Centro de Tecnología Biomédica. Universidad Politécnica de Madrid. 28223 Pozuelo de Alarcón (Madrid), Spain.|Departamento de Ciencia de Materiales. ETSI Caminos, Canales y Puertos. Universidad Politécnica de Madrid, 28040 Madrid, Spain.
authors.forename: G R
authors.initials: GR
authors.lastname: Plaza
authors.affiliation: European Synchroton Radiation Facility, B.P. 220, F-38043, Grenoble Cedex, France.
authors.forename: C
authors.initials: C
authors.lastname: Riekel
authors.affiliation: European Synchroton Radiation Facility, B.P. 220, F-38043, Grenoble Cedex, France.
authors.forename: M
authors.initials: M
authors.lastname: Burghammer
authors.affiliation: Centro de Tecnología Biomédica. Universidad Politécnica de Madrid. 28223 Pozuelo de Alarcón (Madrid), Spain.|Departamento de Ciencia de Materiales. ETSI Caminos, Canales y Puertos. Universidad Politécnica de Madrid, 28040 Madrid, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Elices
authors.affiliation: Centro de Tecnología Biomédica. Universidad Politécnica de Madrid. 28223 Pozuelo de Alarcón (Madrid), Spain.|Departamento de Ciencia de Materiales. ETSI Caminos, Canales y Puertos. Universidad Politécnica de Madrid, 28040 Madrid, Spain.
authors.forename: G
authors.initials: G
authors.lastname: Guinea
authors.affiliation: Centro de Tecnología Biomédica. Universidad Politécnica de Madrid. 28223 Pozuelo de Alarcón (Madrid), Spain.|Departamento de Ciencia de Materiales. ETSI Caminos, Canales y Puertos. Universidad Politécnica de Madrid, 28040 Madrid, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Pérez-Rigueiro
mesh_terms: D000818:Animals; D005075:Biological Evolution; D010802:Phylogeny; D047011:Silk / Q000737:chemistry* / Q000648:ultrastructure*; D013112:Spiders; D013718:Tensile Strength; D014961:X-Ray Diffraction
chemical_list: D047011:Silk