Unravelling the biodiversity of nanoscale signatures of spider silk fibres

• Published in: Nature communications Vol. 4; no. 1; p. 3014
• Main Authors: Silva, Luciano P., Rech, Elibio L.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 18.12.2013; Nature Publishing Group
• Subjects: 101/47; 101/58; 142/136; 639/301/54; 639/925; Animals; Biodiversity; Biopolymers - chemistry; Cluster Analysis; Elasticity; Fibroins - chemistry; Fibroins - ultrastructure; Humanities and Social Sciences; Microscopy, Atomic Force; multidisciplinary; Nanostructures - chemistry; Peptide Hydrolases - chemistry; Phylogeny; Protein Engineering; Recombinant Proteins - chemistry; Science; Science (multidisciplinary); Spiders; Stress, Mechanical; Temperature; Tensile Strength
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms4014

Living organisms are masters at designing outstanding self-assembled nanostructures through a hierarchical organization of modular proteins. Protein-based biopolymers improved and selected by the driving forces of molecular evolution are among the most impressive archetypes of nanomaterials. One of these biomacromolecules is the myriad of compound fibroins of spider silks, which combine surprisingly high tensile strength with great elasticity. However, no consensus on the nano-organization of spider silk fibres has been reached. Here we explore the biodiversity of spider silk fibres, focusing on nanoscale characterization with high-resolution atomic force microscopy. Our results reveal an evolution of the nanoroughness, nanostiffness, nanoviscoelastic, nanotribological and nanoelectric organization of microfibres, even when they share similar sizes and shapes. These features are related to unique aspects of their molecular structures. The results show that combined nanoscale analyses of spider silks may enable the screening of appropriate motifs for bioengineering synthetic fibres from recombinant proteins. Spider silk fibre is known to be composed of arrangements of structural domains. Here, the authors implement multiple atomic force microscopy modes to study the nanoscale morphology and mechanics of these fibres from nine spiders, and relate them to their molecular structures.