1
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Yoshioka T, Kameda T, Burghammer M, Riekel C. Mesoscale Confinement in Bagworm Silk: A Hidden Structural Organization. NANO LETTERS 2023; 23:827-834. [PMID: 36662558 DOI: 10.1021/acs.nanolett.2c03734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
While silk fibers produced by silkworms and spiders are frequently described as a network of amorphous protein chains reinforced by crystalline β-sheet nanodomains, the importance of higher-order, self-assembled structures has been recognized for advanced modeling of mechanical properties. General acceptance of hierarchical structural models is, however, currently limited by lack of experimental results. Indeed, X-ray scattering studies of spider's dragline-type fibers have been particularly limited by low crystallinities. Here we are reporting on probing the local structure of exceptionally crystalline bagworm silk fibers by X-ray nanobeam scattering. Probing the comparable thickness of cross sections with an X-ray nanobeam allows removing the strong scattering background from the outer sericin layer and reveals a hidden structural organization due to a radial gradient in diameters of mesoscale nanofibrillar bundles in the fibroin phase. Our results provide direct support for lateral interactions between nanofibrils.
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Affiliation(s)
- Taiyo Yoshioka
- Silk Materials Research Group, National Agriculture and Food Research Organization (NARO), 1-2 Owashi, Tsukuba, Ibaraki 305-8634, Japan
| | - Tsunenori Kameda
- Silk Materials Research Group, National Agriculture and Food Research Organization (NARO), 1-2 Owashi, Tsukuba, Ibaraki 305-8634, Japan
| | - Manfred Burghammer
- The European Synchrotron (ESRF), 71 Avenue des Martyrs, CS40220, 38043 Grenoble Cedex 9, France
| | - Christian Riekel
- The European Synchrotron (ESRF), 71 Avenue des Martyrs, CS40220, 38043 Grenoble Cedex 9, France
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2
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Pena-Francesch A, Jung H, Tyagi M, Demirel MC. Diffusive Dynamic Modes of Recombinant Squid Ring Teeth Proteins by Neutron Spectroscopy. Biomacromolecules 2022; 23:3165-3173. [PMID: 35767422 DOI: 10.1021/acs.biomac.2c00266] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Stimuli-responsive structural proteins are emerging as promising biocompatible materials for a wide range of biological and nonbiological applications. To understand the physical properties of structural proteins and to replicate their performance in biosynthetic systems, there is a need to understand the molecular mechanisms and relationships that regulate their structure, dynamics, and properties. Here, we study the dynamics of a recombinant squid-inspired protein from Loligo vulgaris (Lv18) by elastic and quasielastic neutron scattering (QENS) to understand the connection between nanostructure, chain dynamics, and mechanical properties. Lv18 is a semicrystalline structural protein, which is plasticized by water above its glass transition temperature at 35 °C. Elastic scans revealed an increased protein chain mobility upon hydration, superimposed dynamic processes, and a decrease in dynamic transition temperatures. Further analysis by QENS revealed that while dry Lv18 protein dynamics are dominated by localized methyl group rotations, hydrated Lv18 dynamics are dominated by the confined diffusion of flexible chains within a β-sheet nanocrystalline network (8 Å of confinement radius). Our findings establish a relationship between the segment block architecture of Lv18, the diffusive motions within the protein structure, and the mechanical properties of recombinant squid proteins, which will advance the molecular design of novel high-performance protein-inspired materials with tailored dynamics and mechanical properties.
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Affiliation(s)
- Abdon Pena-Francesch
- Department of Materials Science and Engineering, Macromolecular Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States.,Department of Engineering Science and Mechanics, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Huihun Jung
- Department of Engineering Science and Mechanics, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Madhusudan Tyagi
- NIST Center for Neutron Research, Gaithersburg, Maryland 20899, United States.,Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, United States
| | - Melik C Demirel
- Department of Engineering Science and Mechanics, Pennsylvania State University, University Park, Pennsylvania 16802, United States.,Materials Research Institute, and Huck Institutes of Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, United States
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3
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Cohen N, Eisenbach CD. Humidity-Driven Supercontraction and Twist in Spider Silk. PHYSICAL REVIEW LETTERS 2022; 128:098101. [PMID: 35302814 DOI: 10.1103/physrevlett.128.098101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 01/05/2022] [Accepted: 02/09/2022] [Indexed: 06/14/2023]
Abstract
Spider silk is a protein material that exhibits extraordinary and nontrivial properties such as the ability to soften, decrease in length (i.e., supercontract), and twist upon exposure to high humidity. These behaviors stem from a unique microstructure in combination with a transition from glassy to rubbery as a result of humidity-driven diffusion of water. In this Letter we propose four length scales that govern the mechanical response of the silk during this transition. In addition, we develop a model that describes the microstructural evolution of the spider silk thread and explains the response due to the diffusion of water molecules. The merit of the model is demonstrated through an excellent agreement to experimental findings. The insights from this Letter can be used as a microstructural design guide to enable the development of new materials with unique spiderlike properties.
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Affiliation(s)
- Noy Cohen
- Department of Materials Science and Engineering, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Claus D Eisenbach
- Materials Research Laboratory, University of California, Santa Barbara, California 93106, USA and Institute for Polymer Chemistry, University of Stuttgart, D-70569 Stuttgart, Germany
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4
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Synchrotron FTIR Microspectroscopy Methods to Understand the Conformation of Single Animal Silk Fibers. Methods Mol Biol 2021. [PMID: 34472066 DOI: 10.1007/978-1-0716-1574-4_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Animal silks have received extensive attention in these years due to their unique mechanical properties. The study of the structure-property relationship of animal silks is not only critical for the understanding of the design secrets of natural materials but also can inspire the engineering material designs. Fourier transform infrared spectroscopy (FTIR) has been used to study the secondary structure of animal silk, which is considered to be critical to the mechanical properties of animal silk. However, most of these characterizations are conducted on silk fiber bundles. In this respect, synchrotron FTIR microspectroscopy (S-micro FTIR) has unique advantages in characterizing single animal silks, as S-micro FTIR has significant advantages in ultrahigh brightness and high spatial resolution to characterize samples with small size. Here, we will introduce the methods for using synchrotron FTIR microspectroscopy to analyze the conformation and orientation of single animal silk fibers, which would be an efficient method to elucidate the "structure-property" relationship within animal silks.
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5
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Nanoscale Material Heterogeneity of Glowworm Capture Threads Revealed by AFM. Molecules 2021; 26:molecules26123500. [PMID: 34201363 PMCID: PMC8226719 DOI: 10.3390/molecules26123500] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 05/29/2021] [Accepted: 06/04/2021] [Indexed: 11/17/2022] Open
Abstract
Adhesive materials used by many arthropods for biological functions incorporate sticky substances and a supporting material that operate synergistically by exploiting substrate attachment and energy dissipation. While there has been much focus on the composition and properties of the sticky glues of these bio-composites, less attention has been given to the materials that support them. In particular, as these materials are primarily responsible for dissipation during adhesive pull-off, little is known of the structures that give rise to functionality, especially at the nano-scale. In this study we used tapping mode atomic force microscopy (TM-AFM) to analyze unstretched and stretched glowworm (Arachnocampa tasmaniensis) capture threads and revealed nano-scale features corresponding to variation in surface structure and elastic modulus near the surface of the silk. Phase images demonstrated a high resolution of viscoelastic variation and revealed mostly globular and elongated features in the material. Increased vertical orientation of 11–15 nm wide fibrillar features was observed in stretched threads. Fast Fourier transform analysis of phase images confirmed these results. Relative viscoelastic properties were also highly variable at inter- and intra-individual levels. Results of this study demonstrate the practical usefulness of TM-AFM, especially phase angle imaging, in investigating the nano-scale structures that give rise to macro-scale function of soft and highly heterogeneous materials of both natural and synthetic origins.
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6
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Riekel C, Burghammer M, Rosenthal M. Mesoscale structures in amorphous silks from a spider's orb-web. Sci Rep 2020; 10:18205. [PMID: 33097740 PMCID: PMC7584646 DOI: 10.1038/s41598-020-74638-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 09/24/2020] [Indexed: 11/30/2022] Open
Abstract
Of the 7-8 silk fibers making up an orb-web only the hierarchical structural organization of semicrystalline radial fibers -composed of major ampullate silk- has been studied in detail, given its fascinating mechanical features. While major ampullate silk's nanofibrillar morphology is well established, knowhow on mesoscale (> 50-100 nm) assembly and its contribution to mechanical performance is limited. Much less is known on the hierarchical structural organization of other, generally less crystalline fibers contributing to an orb-webs' function. Here we show by scanning X-ray micro&nanodiffraction that two fully amorphous, fine silk fibers from the center of an orb-web have different mesoscale features. One of the fibers has a fibrillar composite structure resembling stiff egg case silk. The other fiber has a skin-core structure based on a nanofibrillar ribbon wound around a disordered core. A fraction of nanofibrils appears to have assembled into mesoscale fibrils. This fiber becomes readily attached to the coat of major ampullate silk fibers. We observe that a detached fiber has ripped out the glycoprotein skin-layer containing polyglycine II nanocrystallites. The anchoring of the fiber in the coat suggests that it could serve for strengthening the tension and cohesion of major ampullate silk fibers.
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Affiliation(s)
- Christian Riekel
- The European Synchrotron, ESRF, CS40220, 38043, Grenoble Cedex 9, France.
| | - Manfred Burghammer
- The European Synchrotron, ESRF, CS40220, 38043, Grenoble Cedex 9, France
| | - Martin Rosenthal
- The European Synchrotron, ESRF, CS40220, 38043, Grenoble Cedex 9, France
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7
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Asakura T, Nishimura A, Aoki A, Naito A. Packing Structure of Antiparallel β-Sheet Polyalanine Region in a Sequential Model Peptide of Nephila clavipes Dragline Silk Studied Using 13C Solid-State NMR and MD Simulation. Biomacromolecules 2019; 20:3884-3894. [PMID: 31449407 DOI: 10.1021/acs.biomac.9b00969] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Packing structures of polyalanine regions, which are considered to be the reason for the extremely high strength of spider dragline silks, were studied using a series of sequential peptides: (Glu)4GlyGlyLeuGlyGlyGlnGlyAlaGly(Ala)nGlyGlyAlaGlyGlnGlyGlyTyrGlyGly(Glu)4 (n = 3-8) using 13C solid-state NMR spectroscopy. The conformations of (Ala)n in the freeze-dried peptides changed gradually with increasing n from random coils to α-helices with partial antiparallel β-sheet (AP-β) structures. Conversely, all the insolubilized peptides, n = 6-8 after low-pH treatment and n = 4-8 after formic acid/methanol treatment, formed AP-β structures with significant amounts of staggered packing arrangements. These results are different from previously obtained results for pure alanine oligopeptides, that is, AP-β (Ala)n formed rectangular packing for less than n = 6 but staggered packings for n ≥ 7. The 13C-labeled peptides were also used to confirm the staggered packing arrangements from NMR dynamics. Furthermore, a MD simulation supported the observed results.
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Affiliation(s)
- Tetsuo Asakura
- Department of Biotechnology , Tokyo University of Agriculture and Technology , Koganei, Tokyo 184-8588 , Japan
| | - Akio Nishimura
- Department of Biotechnology , Tokyo University of Agriculture and Technology , Koganei, Tokyo 184-8588 , Japan
| | - Akihiro Aoki
- Department of Biotechnology , Tokyo University of Agriculture and Technology , Koganei, Tokyo 184-8588 , Japan
| | - Akira Naito
- Department of Biotechnology , Tokyo University of Agriculture and Technology , Koganei, Tokyo 184-8588 , Japan
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8
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Rogovina SZ, Prut EV, Berlin AA. Composite Materials Based on Synthetic Polymers Reinforced with Natural Fibers. POLYMER SCIENCE SERIES A 2019. [DOI: 10.1134/s0965545x19040084] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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9
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Asakura T, Matsuda H, Aoki A, Kataoka N, Imai A. Conformational change of 13C-labeled 47-mer model peptides of Nephila clavipes dragline silk in poly(vinyl alcohol) film by stretching studied by 13C solid-state NMR and molecular dynamics simulation. Int J Biol Macromol 2019; 131:654-665. [PMID: 30902719 DOI: 10.1016/j.ijbiomac.2019.03.112] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Revised: 03/18/2019] [Accepted: 03/18/2019] [Indexed: 12/23/2022]
Abstract
For determination of the conformation of irregular sequences in glycine-rich region of the Nephila clavipes spider dragline silk, the combination of 13C selectively labeled model peptides for the typical primary structure and their 13C solid-state NMR observations is very useful (T. Asakura et al. Macromolecules. 51 (2018) 3608-3619). However, spiders produce the fiber through the stretching process in nature and therefore, it is difficult to study conformational change by stretching as mimic using the model peptides because these are generally in the powder form. In this paper, 13C selectively labeled three model peptides, (Glu)4(Ala)6GlyGly12Ala13Gly14GlnGlyGlyTyrGlyGlyLeuGlySerGlnGly25Ala26Gly27ArgGly-GlyLeuGlyGlyGlnGly35Ala36Gly37(Ala)6(Glu)4 with three underlined 13C labeled blocks and their poly(vinyl alcohol) blend films were prepared and the conformational changes of these peptides were monitored by stretching of the films using 13C solid-state NMR. In addition, the molecular dynamics simulation was done to evaluate change in the conformation of the sequence by stretching theoretically. The fractions of β-sheet of Ala36 and Gly37 residues in glycine-rich region adjacent to the C-terminal (Ala)6 sequence increased significantly by stretching compared with those of other 13C labeled Ala and Gly residues.
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Affiliation(s)
- Tetsuo Asakura
- Department of Biotechnology, Tokyo University of Agriculture and Technology, 2-24-16, Nakacho, Koganei, Tokyo 184-8588, Japan.
| | - Hironori Matsuda
- Department of Biotechnology, Tokyo University of Agriculture and Technology, 2-24-16, Nakacho, Koganei, Tokyo 184-8588, Japan
| | - Akihiro Aoki
- Department of Biotechnology, Tokyo University of Agriculture and Technology, 2-24-16, Nakacho, Koganei, Tokyo 184-8588, Japan
| | - Naomi Kataoka
- Department of Biotechnology, Tokyo University of Agriculture and Technology, 2-24-16, Nakacho, Koganei, Tokyo 184-8588, Japan
| | - Akiko Imai
- Department of Biotechnology, Tokyo University of Agriculture and Technology, 2-24-16, Nakacho, Koganei, Tokyo 184-8588, Japan
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10
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Abstract
Spider silk exhibits a combination of outstanding tensile strength and extensibility unique among all synthetic and biogenic polymer fibers. It has thus generated great interest to understand protein-based high-toughness materials and inspired the design of similar synthetic materials. The unrivaled properties of silk fibers have been recognized to be intimately related to their hierarchical structure. However, in the absence of unambiguous experimental evidence, competing and incompatible structural models of natural silk fibers have been proposed, some of them including various types of fibrillar components. Here we show that the fibers of the recluse (Loxosceles) spider exhibit the typical tensile properties of a very good spider silk and are entirely composed of 20 nm diameter protein fibrils that are more than 1 μm long. Based on these findings, we developed the most detailed structural model for any silk directly supported by experimental evidence. Our work suggests that all the key properties of a spider silk are implemented within a single nanofibril, and we have isolated and imaged such a nanofibril from a native spider silk fiber. The nanofibril breaking force was estimated to be ≈120 nN. Our work underlines the importance of nanofibrils and furthers the understanding of the structure-property relationships of silk, with wide-ranging implications for silk research and the design of silk-inspired high-performance materials.
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Affiliation(s)
- Qijue Wang
- Applied Science Department, The College of William and Mary, P.O. Box 8795, Williamsburg, Virginia 23187-8795, United States
| | - Hannes C. Schniepp
- Applied Science Department, The College of William and Mary, P.O. Box 8795, Williamsburg, Virginia 23187-8795, United States
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11
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Asakura T, Matsuda H, Kataoka N, Imai A. Changes in the Local Structure of Nephila clavipes Dragline Silk Model Peptides upon Trifluoroacetic Acid, Low pH, Freeze-Drying, and Hydration Treatments Studied by 13C Solid-State NMR. Biomacromolecules 2018; 19:4396-4410. [DOI: 10.1021/acs.biomac.8b01267] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Tetsuo Asakura
- Department of Biotechnology, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan
| | - Hironori Matsuda
- Department of Biotechnology, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan
| | - Naomi Kataoka
- Department of Biotechnology, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan
| | - Akiko Imai
- Department of Biotechnology, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan
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12
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Asakura T, Tasei Y, Matsuda H, Naito A. Dynamics of Alanine Methyl Groups in Alanine Oligopeptides and Spider Dragline Silks with Different Packing Structures As Studied by 13C Solid-State NMR Relaxation. Macromolecules 2018. [DOI: 10.1021/acs.macromol.8b01402] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tetsuo Asakura
- Department of Biotechnology, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan
| | - Yugo Tasei
- Department of Biotechnology, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan
| | - Hironori Matsuda
- Department of Biotechnology, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan
| | - Akira Naito
- Department of Biotechnology, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan
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13
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Asakura T, Tasei Y, Aoki A, Nishimura A. Mixture of Rectangular and Staggered Packing Arrangements of Polyalanine Region in Spider Dragline Silk in Dry and Hydrated States As Revealed by 13C NMR and X-ray Diffraction. Macromolecules 2018. [DOI: 10.1021/acs.macromol.7b02627] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Tetsuo Asakura
- Department of Biotechnology, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan
| | - Yugo Tasei
- Department of Biotechnology, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan
| | - Akihiro Aoki
- Department of Biotechnology, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan
| | - Akio Nishimura
- Department of Biotechnology, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan
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14
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Wan Q, Abrams KJ, Masters RC, Talari ACS, Rehman IU, Claeyssens F, Holland C, Rodenburg C. Mapping Nanostructural Variations in Silk by Secondary Electron Hyperspectral Imaging. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29:1703510. [PMID: 29116662 DOI: 10.1002/adma.201703510] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 08/29/2017] [Indexed: 06/07/2023]
Abstract
Nanostructures underpin the excellent properties of silk. Although the bulk nanocomposition of silks is well studied, direct evidence of the spatial variation of nanocrystalline (ordered) and amorphous (disordered) structures remains elusive. Here, secondary electron hyperspectral imaging can be exploited for direct imaging of hierarchical structures in carbon-based materials, which cannot be revealed by any other standard characterization methods. Through applying this technique to silks from domesticated (Bombyx mori) and wild (Antheraea mylitta) silkworms, a variety of previously unseen features are reported, highlighting the local interplay between ordered and disordered structures. This technique is able to differentiate composition on the nanoscale and enables in-depth studies into the relationship between morphology and performance of these complex biopolymer systems.
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Affiliation(s)
- Quan Wan
- Department of Materials Science and Engineering, University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield, S1 3JD, UK
| | - Kerry J Abrams
- Department of Materials Science and Engineering, University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield, S1 3JD, UK
| | - Robert C Masters
- Department of Materials Science and Engineering, University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield, S1 3JD, UK
| | - Abdullah C S Talari
- Department of Materials Science and Engineering, University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield, S1 3JD, UK
| | - Ihtesham U Rehman
- Department of Materials Science and Engineering, University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield, S1 3JD, UK
| | - Frederik Claeyssens
- Department of Materials Science and Engineering, University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield, S1 3JD, UK
| | - Chris Holland
- Department of Materials Science and Engineering, University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield, S1 3JD, UK
| | - Cornelia Rodenburg
- Department of Materials Science and Engineering, University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield, S1 3JD, UK
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15
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Abstract
The emergence of order from disorder is a topic of vital interest. We here propose that long-range order can arise from a randomly arranged two-phase material under mechanical load. Using Small-Angle Neutron Scattering (SANS) experiments and Molecular Dynamics based finite element (FE) models we show evidence for stress-induced ordering in spider dragline silk. Both methods show striking quantitative agreement of the position, shift and intensity increase of the long period upon stretching. We demonstrate that mesoscopic ordering does not originate from silk-specific processes such as strain-induced crystallization on the atomistic scale or the alignment of tilted crystallites. It instead is a general phenomenon arising from a non-affine deformation that enhances density fluctuations of the stiff and soft phases along the direction of stress. Our results suggest long-range ordering, analogously to the coalescence of defects in materials, as a wide-spread phenomenon to be exploited for tuning the mechanical properties of many hybrid stiff and soft materials.
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16
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Riekel C, Burghammer M, Dane TG, Ferrero C, Rosenthal M. Nanoscale Structural Features in Major Ampullate Spider Silk. Biomacromolecules 2016; 18:231-241. [PMID: 28001374 DOI: 10.1021/acs.biomac.6b01537] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Spider major ampullate silk is often schematically represented as a two-phase material composed of crystalline nanodomains in an amorphous matrix. Here we are interested in revealing its more complex nanoscale organization by probing Argiope bruennichi dragline-type fibers using scanning X-ray nanodiffraction. This allows resolving transversal structural features such as an about 1 μm skin layer composed of around 100 nm diameter nanofibrils serving presumably as an elastic sheath. The core consists of a composite of several nm size crystalline nanodomains with poly(l-alanine) microstructure, embedded in a polypeptide network with short-range order. Stacks of nanodomains separated by less ordered nanosegments form nanofibrils with a periodic axial density modulation which is particularly sensitive to radiation damage. The precipitation of larger β-type nanocrystallites in the outer core-shell is attributed to MaSp1 protein molecules.
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Affiliation(s)
- Christian Riekel
- The European Synchrotron (ESRF) , CS40220, F-38043 Grenoble Cedex 9, France
| | - Manfred Burghammer
- The European Synchrotron (ESRF) , CS40220, F-38043 Grenoble Cedex 9, France.,Department of Analytical Chemistry, Ghent University , Krijgslaan 281, S12B-9000 Ghent, Belgium
| | - Thomas G Dane
- The European Synchrotron (ESRF) , CS40220, F-38043 Grenoble Cedex 9, France
| | - Claudio Ferrero
- The European Synchrotron (ESRF) , CS40220, F-38043 Grenoble Cedex 9, France
| | - Martin Rosenthal
- The European Synchrotron (ESRF) , CS40220, F-38043 Grenoble Cedex 9, France
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17
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Schneider D, Gomopoulos N, Koh CY, Papadopoulos P, Kremer F, Thomas EL, Fytas G. Nonlinear control of high-frequency phonons in spider silk. NATURE MATERIALS 2016; 15:1079-83. [PMID: 27454046 DOI: 10.1038/nmat4697] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 06/15/2016] [Indexed: 05/26/2023]
Abstract
Spider dragline silk possesses superior mechanical properties compared with synthetic polymers with similar chemical structure due to its hierarchical structure comprised of partially crystalline oriented nanofibrils. To date, silk's dynamic mechanical properties have been largely unexplored. Here we report an indirect hypersonic phononic bandgap and an anomalous dispersion of the acoustic-like branch from inelastic (Brillouin) light scattering experiments under varying applied elastic strains. We show the mechanical nonlinearity of the silk structure generates a unique region of negative group velocity, that together with the global (mechanical) anisotropy provides novel symmetry conditions for gap formation. The phononic bandgap and dispersion show strong nonlinear strain-dependent behaviour. Exploiting material nonlinearity along with tailored structural anisotropy could be a new design paradigm to access new types of dynamic behaviour.
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Affiliation(s)
- Dirk Schneider
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Nikolaos Gomopoulos
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Cheong Y Koh
- Functional and Smart Materials Laboratory, Emerging Systems, DSO National Laboratories, S117605 Singapore, Singapore
| | - Periklis Papadopoulos
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
- Department of Physics, University of Ioannina, 45110 Ioannina, Greece
| | - Friedrich Kremer
- Institute of Experimental Physics I, Linnéstr. 5, University of Leipzig, 04103 Leipzig, Germany
| | - Edwin L Thomas
- Department of Materials Science and Nano-Engineering, Rice University, Houston, Texas 77030, USA
| | - George Fytas
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
- Department of Materials Science University of Crete and IESL-F.O.R.T.H, 77110 Heraklion, Greece
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18
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Krasnov I, Seydel T, Greving I, Blankenburg M, Vollrath F, Müller M. Strain-dependent fractional molecular diffusion in humid spider silk fibres. J R Soc Interface 2016; 13:20160506. [PMID: 27628174 PMCID: PMC5046950 DOI: 10.1098/rsif.2016.0506] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 08/22/2016] [Indexed: 11/12/2022] Open
Abstract
Spider silk is a material well known for its outstanding mechanical properties, combining elasticity and tensile strength. The molecular mobility within the silk's polymer structure on the nanometre length scale importantly contributes to these macroscopic properties. We have therefore investigated the ensemble-averaged single-particle self-dynamics of the prevailing hydrogen atoms in humid spider dragline silk fibres on picosecond time scales in situ as a function of an externally applied tensile strain. We find that the molecular diffusion in the amorphous fraction of the oriented fibres can be described by a generalized fractional diffusion coefficient Kα that is independent of the observation length scale in the probed range from approximately 0.3-3.5 nm. Kα increases towards a diffusion coefficient of the classical Fickian type with increasing tensile strain consistent with an increasing loss of memory or entropy in the polymer matrix.
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Affiliation(s)
- Igor Krasnov
- Institut für Experimentelle und Angewandte Physik, Universität Kiel, 24098 Kiel, Germany Institute of Materials Research, Helmholtz-Zentrum Geesthacht (HZG), 21502 Geesthacht, Germany
| | - Tilo Seydel
- Institut Max von Laue-Paul Langevin (ILL), CS 20156, 38042 Grenoble, France
| | - Imke Greving
- Institute of Materials Research, Helmholtz-Zentrum Geesthacht (HZG), 21502 Geesthacht, Germany
| | - Malte Blankenburg
- Institut für Experimentelle und Angewandte Physik, Universität Kiel, 24098 Kiel, Germany Institute of Materials Research, Helmholtz-Zentrum Geesthacht (HZG), 21502 Geesthacht, Germany
| | - Fritz Vollrath
- Department of Zoology, University of Oxford, Oxford OX13PS, UK
| | - Martin Müller
- Institut für Experimentelle und Angewandte Physik, Universität Kiel, 24098 Kiel, Germany Institute of Materials Research, Helmholtz-Zentrum Geesthacht (HZG), 21502 Geesthacht, Germany
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Persistence and variation in microstructural design during the evolution of spider silk. Sci Rep 2015; 5:14820. [PMID: 26438975 PMCID: PMC4594040 DOI: 10.1038/srep14820] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 08/24/2015] [Indexed: 01/17/2023] Open
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.
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Krasnov I, Seydel T, Müller M. Fractional dynamics in silk: From molecular picosecond subdiffusion to macroscopic long-time relaxation. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 91:042716. [PMID: 25974536 DOI: 10.1103/physreve.91.042716] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Indexed: 06/04/2023]
Abstract
Structural relaxations in humid silk fibers exposed to tensile stress have been reported to take place on a very wide range of time scales from a few milliseconds to several hours. The time-dependence of the measured tensile force following a quasi-instantaneously applied external strain on the fibers can be understood in terms of a fractional viscoelastic relaxation function introducing memory effects by which the mechanical state of a fiber depends on its tensile history. An analog fractional relaxation also gives rise to the subdiffusion observed on picosecond time scales, which governs the mobility of the amorphous polymer chains and adsorbed water on the molecular level. The reduction of the subdiffusive memory effect in stretched fibers compared to native fibers is consistent with the higher order of the polymers in the stretched state.
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Affiliation(s)
- Igor Krasnov
- Institut für Experimentelle und Angewandte Physik, Universität Kiel, D-24098 Kiel, Germany
- Institute of Materials Research, Helmholtz-Zentrum Geesthacht (HZG), D-21502 Geesthacht, Germany
| | - Tilo Seydel
- Institut Max von Laue-Paul Langevin (ILL), CS 20156, F-38042 Grenoble, France
| | - Martin Müller
- Institute of Materials Research, Helmholtz-Zentrum Geesthacht (HZG), D-21502 Geesthacht, Germany
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Huang W, Krishnaji S, Tokareva OR, Kaplan D, Cebe P. Influence of Water on Protein Transitions: Morphology and Secondary Structure. Macromolecules 2014. [DOI: 10.1021/ma5016227] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Wenwen Huang
- Department of Physics and Astronomy,
Center for Nanoscopic Physics, ‡Department of Chemistry, and §Department of
Biomedical Engineering, Tufts University, Medford, Massachusetts 02155, United States
| | - Sreevidhya Krishnaji
- Department of Physics and Astronomy,
Center for Nanoscopic Physics, ‡Department of Chemistry, and §Department of
Biomedical Engineering, Tufts University, Medford, Massachusetts 02155, United States
| | - Olena Rabotyagova Tokareva
- Department of Physics and Astronomy,
Center for Nanoscopic Physics, ‡Department of Chemistry, and §Department of
Biomedical Engineering, Tufts University, Medford, Massachusetts 02155, United States
| | - David Kaplan
- Department of Physics and Astronomy,
Center for Nanoscopic Physics, ‡Department of Chemistry, and §Department of
Biomedical Engineering, Tufts University, Medford, Massachusetts 02155, United States
| | - Peggy Cebe
- Department of Physics and Astronomy,
Center for Nanoscopic Physics, ‡Department of Chemistry, and §Department of
Biomedical Engineering, Tufts University, Medford, Massachusetts 02155, United States
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Giesa T, Pugno NM, Wong JY, Kaplan DL, Buehler MJ. What's inside the box? - Length-scales that govern fracture processes of polymer fibers. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2014; 26:412-7. [PMID: 24431127 PMCID: PMC4976486 DOI: 10.1002/adma.201303323] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Indexed: 05/15/2023]
Abstract
This work shows that multiple length-scales must be considered concurrently to explain a polymer fiber's impressive mechanical performance and resilience. The considerations of interatomic interactions alone cannot explain the fracture strength observed in biological fibers. Instead, the fracture strength of a fiber depends strongly on the length-scale of observation, including a fiber's sensitivity with respect to cracks and other flaws.
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Affiliation(s)
- Tristan Giesa
- Laboratory for Atomistic and Molecular Mechanics, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 77 Mass. Ave. Room 1-235A&B, Cambridge, MA, 02139, USA
| | - Nicola M. Pugno
- Laboratory of Bio-Inspired & Graphene Nanomechanics, Department of Civil, Environmental and Mechanical Engineering, Università di Trento, Via Mesiano, 77, I-38123, Trento, Italy
- Center for Materials and Microsystems, Fondazione Bruno Kessler, Via Sommarive, 18, I-38123, Trento, Italy
| | - Joyce Y. Wong
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA, 02215, USA
| | - David L. Kaplan
- Department of Biomedical Engineering, Tufts University, Medford, MA, 02155, USA
| | - Markus J. Buehler
- Laboratory for Atomistic and Molecular Mechanics, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 77 Mass. Ave. Room 1-235A&B, Cambridge, MA, 02139, USA
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24
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Ling S, Qi Z, Knight DP, Huang Y, Huang L, Zhou H, Shao Z, Chen X. Insight into the structure of single Antheraea pernyi silkworm fibers using synchrotron FTIR microspectroscopy. Biomacromolecules 2013; 14:1885-92. [PMID: 23607809 DOI: 10.1021/bm400267m] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Synchrotron FTIR (S-FTIR) microspectroscopy was used to monitor both protein secondary structures (conformations) and their orientations in single cocoon silk fibers of the Chinese Tussah silk moth ( Antheraea pernyi ). In addition, to understand further the relationship between structure and properties of single silk fibers, we studied the changes of orientation and content of different secondary structures in single A. pernyi silk fibers when subjected to different strains. The results showed that the content and orientation of β-sheet was almost unchanged for strains from 0 to 0.3. However, the orientation of α-helix and random coil improved progressively with increasing strain, with a parallel decrease in α-helix content and an increase in random coil. This clearly indicates that most of the deformation upon stretching of the single fiber is due to the change of orientation in the amorphous regions coupled with a conversion of some of the α-helix to random coil. These observations provide an explanation for the supercontraction behavior of certain animal silks and are likely to facilitate understanding and optimization of postdrawing used in the conjunction with the wet-spinning of silk fibers from regenerated silk solutions. Thus, our work demonstrates the power of S-FTIR microspectroscopy for studying biopolymers.
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Affiliation(s)
- Shengjie Ling
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Laboratory of Advanced Materials, Fudan University , Shanghai, 200433, People's Republic of China
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Greving I, Cai M, Vollrath F, Schniepp HC. Shear-Induced Self-Assembly of Native Silk Proteins into Fibrils Studied by Atomic Force Microscopy. Biomacromolecules 2012; 13:676-82. [DOI: 10.1021/bm201509b] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Imke Greving
- Department of Zoology, University of Oxford, The Tinbergen
Building, Oxford, OX1 3PS, United Kingdom
| | - Minzhen Cai
- Applied Science
Department, The College of William and Mary, Williamsburg, Virginia 23187, United States
| | - Fritz Vollrath
- Department of Zoology, University of Oxford, The Tinbergen
Building, Oxford, OX1 3PS, United Kingdom
| | - Hannes C. Schniepp
- Applied Science
Department, The College of William and Mary, Williamsburg, Virginia 23187, United States
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Holland C, O'Neil K, Vollrath F, Dicko C. Distinct structural and optical regimes in natural silk spinning. Biopolymers 2012; 97:368-73. [PMID: 22240893 DOI: 10.1002/bip.22022] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Accepted: 12/21/2011] [Indexed: 11/11/2022]
Abstract
This study investigates the relationship between birefringence and mechanical properties in the dragline silk of the gold orb weaving spider Nephila edulis. Using a custom birefringence-tensile testing device, we probed the orientation and water-induced swelling of fibers spun at variety of drawing rates ranging from 0.003 to 400 mm s(-1). Our results indicate that based upon drawing rate, silk fibers fall into three distinct regimes each with characteristic orientation and swelling properties. Further investigation using in situ tensile testing reveals interactions between a fiber's drawing speed, mechanical properties, and orientation that support previous model predictions. We propose that simultaneous birefringence-tensile testing provides a unique and readily accessible insight into the structural behavior of this interesting and important biomaterial.
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Affiliation(s)
- Chris Holland
- Department of Zoology, Oxford University, Oxford OX1 3PS, UK
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Elices M, Guinea GV, Plaza GR, Karatzas C, Riekel C, Agulló-Rueda F, Daza R, Pérez-Rigueiro J. Bioinspired Fibers Follow the Track of Natural Spider Silk. Macromolecules 2011. [DOI: 10.1021/ma102291m er] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- M. Elices
- Departamento de Ciencia de Materiales, ETSI Caminos, Canales y Puertos, Universidad Politécnica de Madrid, 28040 Madrid, Spain
| | - G. V. Guinea
- Departamento de Ciencia de Materiales, ETSI Caminos, Canales y Puertos, Universidad Politécnica de Madrid, 28040 Madrid, Spain
| | - G. R. Plaza
- Departamento de Ciencia de Materiales, ETSI Caminos, Canales y Puertos, Universidad Politécnica de Madrid, 28040 Madrid, Spain
| | - C. Karatzas
- Nexia Biotechnologies Inc., Vaudreuil-Dorion, QC J7V 8P5Canada
| | - C. Riekel
- European Synchroton Radiation Facility, B.P. 220, F-38043, Grenoble Cedex, France
| | - F. Agulló-Rueda
- Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, 28049 Madrid, Spain
| | - R. Daza
- Departamento de Ciencia de Materiales, ETSI Caminos, Canales y Puertos, Universidad Politécnica de Madrid, 28040 Madrid, Spain
| | - J. Pérez-Rigueiro
- Departamento de Ciencia de Materiales, ETSI Caminos, Canales y Puertos, Universidad Politécnica de Madrid, 28040 Madrid, Spain
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29
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Elices M, Guinea GV, Plaza GR, Karatzas C, Riekel C, Agulló-Rueda F, Daza R, Pérez-Rigueiro J. Bioinspired Fibers Follow the Track of Natural Spider Silk. Macromolecules 2011. [DOI: 10.1021/ma102291m] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- M. Elices
- Departamento de Ciencia de Materiales, ETSI Caminos, Canales y Puertos, Universidad Politécnica de Madrid, 28040 Madrid, Spain
| | - G. V. Guinea
- Departamento de Ciencia de Materiales, ETSI Caminos, Canales y Puertos, Universidad Politécnica de Madrid, 28040 Madrid, Spain
| | - G. R. Plaza
- Departamento de Ciencia de Materiales, ETSI Caminos, Canales y Puertos, Universidad Politécnica de Madrid, 28040 Madrid, Spain
| | - C. Karatzas
- Nexia Biotechnologies Inc., Vaudreuil-Dorion, QC J7V 8P5Canada
| | - C. Riekel
- European Synchroton Radiation Facility, B.P. 220, F-38043, Grenoble Cedex, France
| | - F. Agulló-Rueda
- Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, 28049 Madrid, Spain
| | - R. Daza
- Departamento de Ciencia de Materiales, ETSI Caminos, Canales y Puertos, Universidad Politécnica de Madrid, 28040 Madrid, Spain
| | - J. Pérez-Rigueiro
- Departamento de Ciencia de Materiales, ETSI Caminos, Canales y Puertos, Universidad Politécnica de Madrid, 28040 Madrid, Spain
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Seydel T, Knoll W, Greving I, Dicko C, Koza MM, Krasnov I, Müller M. Increased molecular mobility in humid silk fibers under tensile stress. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2011; 83:016104. [PMID: 21405741 DOI: 10.1103/physreve.83.016104] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2010] [Indexed: 05/30/2023]
Abstract
Silk fibers are semicrystalline nanocomposite protein fibers with an extraordinary mechanical toughness that changes with humidity. Diffusive or overdamped motion on a molecular level is absent in dry silkworm silk, but present in humid silk at ambient temperature. This microscopic diffusion distinctly depends on the externally applied macroscopic tensile force. Quasielastic and inelastic neutron-scattering data as a function of humidity and of tensile strain on humid silk fibers support the model that both the adsorbed water and parts of the amorphous polymers participate in diffusive motion and are affected by the tensile force. It is notable that the quasielastic linewidth of humid silk at 100% relative humidity increases significantly with the applied force. The effect of the tensile force is discussed in terms of an increasing alignment of the polymer chains in the amorphous fraction with increasing tensile stress which changes the geometrical restrictions of the diffusive motions.
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Affiliation(s)
- Tilo Seydel
- Institut Laue-Langevin, Boîte Postale 156, F-38042 Grenoble, France.
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31
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Creager MS, Jenkins JE, Thagard-Yeaman LA, Brooks AE, Jones JA, Lewis RV, Holland GP, Yarger JL. Solid-state NMR comparison of various spiders' dragline silk fiber. Biomacromolecules 2010; 11:2039-43. [PMID: 20593757 DOI: 10.1021/bm100399x] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Major ampullate (dragline) spider silk is a coveted biopolymer due to its combination of strength and extensibility. The dragline silk of different spiders have distinct mechanical properties that can be qualitatively correlated to the protein sequence. This study uses amino acid analysis and carbon-13 solid-state NMR to compare the molecular composition, structure, and dynamics of major ampullate dragline silk of four orb-web spider species ( Nephila clavipes , Araneus gemmoides , Argiope aurantia , and Argiope argentata ) and one cobweb species ( Latrodectus hesperus ). The mobility of the protein backbone and amino acid side chains in water exposed silk fibers is shown to correlate to the proline content. This implies that regions of major ampullate spidroin 2 protein, which is the only dragline silk protein with any significant proline content, become significantly hydrated in dragline spider silk.
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Affiliation(s)
- Melinda S Creager
- Department of Molecular Biology and Macromolecular Core Facility, University of Wyoming, Laramie, Wyoming 82071, USA
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32
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Ene R, Papadopoulos P, Kremer F. Partial deuteration probing structural changes in supercontracted spider silk. POLYMER 2010. [DOI: 10.1016/j.polymer.2010.08.061] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Martel A, Burghammer M, Davies RJ, Di Cola E, Vendrely C, Riekel C. Silk fiber assembly studied by synchrotron radiation SAXS/WAXS and Raman spectroscopy. J Am Chem Soc 2009; 130:17070-4. [PMID: 19053481 DOI: 10.1021/ja806654t] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We have characterized the steps involved in silk assembly from the protein solution into beta-type fibers by a combination of small-angle and wide-angle X-ray scattering and Raman spectroscopy. The aggregation process was studied in a concentric flow microfluidic cell, which allows mimicking the spinning duct. The fibroin molecule in solution shows an elongated shape with a maximum diameter of 38 nm. During the pH-driven initial assembly step, large-scale aggregates of fibroin molecules with a maximum diameter of about 260 nm are formed. Raman spectroscopy on the dried, fibrous material shows a principally alpha-helical silk I secondary structure, which is transformed gradually into beta-type silk II by increasing immersion times in water. The formation of crystalline beta-sheet domains within the fiber is confirmed by wide-angle X-ray scattering. The assembly process resembles the peptide condensation-ordering model proposed for amyloid cross-beta formation.
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Affiliation(s)
- Anne Martel
- European Synchrotron Radiation Facility, B.P. 220, F-38043 Grenoble Cedex, France
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34
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Inspiration from Natural Silks and Their Proteins. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/s0065-2377(08)00205-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Gebhardt R, Vendrely C, Hanfland M, Riekel C. Silk Fiber Formation after High-Pressure Treatment of Fibroin Solution in a Diamond Anvil Cell. Macromolecules 2008. [DOI: 10.1021/ma801872m] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ronald Gebhardt
- European Synchrotron Radiation Facility, B.P. 220, F-38043 Grenoble Cedex, France
| | - Charlotte Vendrely
- European Synchrotron Radiation Facility, B.P. 220, F-38043 Grenoble Cedex, France
| | - Michael Hanfland
- European Synchrotron Radiation Facility, B.P. 220, F-38043 Grenoble Cedex, France
| | - Christian Riekel
- European Synchrotron Radiation Facility, B.P. 220, F-38043 Grenoble Cedex, France
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Ulrich S, Glišović A, Salditt T, Zippelius A. Diffraction from the beta-sheet crystallites in spider silk. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2008; 27:229-242. [PMID: 18843512 DOI: 10.1140/epje/i2008-10374-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2008] [Revised: 07/11/2008] [Indexed: 05/26/2023]
Abstract
We analyze the wide-angle X-ray scattering from oriented spider silk fibers in terms of a quantitative scattering model, including both structural and statistical parameters of the beta-sheet crystallites of spider silk in the amorphous matrix. The model is based on kinematic scattering theory and allows for rather general correlations of the positional and orientational degrees of freedom, including the crystallite's size, composition and dimension of the unit cell. The model is evaluated numerically and compared to experimental scattering intensities allowing us to extract the geometric and statistical parameters. We show explicitly that for the experimentally found mosaicity (width of the orientational distribution) intercrystallite effects are negligible and the data can be analyzed in terms of single-crystallite scattering, as is usually assumed in the literature.
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Affiliation(s)
- S Ulrich
- Institut für Theoretische Physik, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany.
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Nishiyama Y, Johnson GP, French AD, Forsyth VT, Langan P. Neutron Crystallography, Molecular Dynamics, and Quantum Mechanics Studies of the Nature of Hydrogen Bonding in Cellulose Iβ. Biomacromolecules 2008; 9:3133-40. [DOI: 10.1021/bm800726v] [Citation(s) in RCA: 186] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yoshiharu Nishiyama
- Centre de Recherches sur les Macromolécules Végétales of CNRS, affiliated with the Joseph Fourier University of Grenoble, BP 53, 38041 Grenoble Cedex 9, France, Southern Regional Research Center, United States Department of Agriculture, 1100 Robert E. Lee Boulevard, New Orleans, Louisiana 70124, Partnership for Structural Biology, Institute Laue Langevin, 6 Rue Jules Horowitz, F-38042 Grenoble, France, EPSAM/ISTM, Keele University, Keele, Staffordshire ST5 5BG, England, and Bioscience Division, Los
| | - Glenn P. Johnson
- Centre de Recherches sur les Macromolécules Végétales of CNRS, affiliated with the Joseph Fourier University of Grenoble, BP 53, 38041 Grenoble Cedex 9, France, Southern Regional Research Center, United States Department of Agriculture, 1100 Robert E. Lee Boulevard, New Orleans, Louisiana 70124, Partnership for Structural Biology, Institute Laue Langevin, 6 Rue Jules Horowitz, F-38042 Grenoble, France, EPSAM/ISTM, Keele University, Keele, Staffordshire ST5 5BG, England, and Bioscience Division, Los
| | - Alfred D. French
- Centre de Recherches sur les Macromolécules Végétales of CNRS, affiliated with the Joseph Fourier University of Grenoble, BP 53, 38041 Grenoble Cedex 9, France, Southern Regional Research Center, United States Department of Agriculture, 1100 Robert E. Lee Boulevard, New Orleans, Louisiana 70124, Partnership for Structural Biology, Institute Laue Langevin, 6 Rue Jules Horowitz, F-38042 Grenoble, France, EPSAM/ISTM, Keele University, Keele, Staffordshire ST5 5BG, England, and Bioscience Division, Los
| | - V. Trevor Forsyth
- Centre de Recherches sur les Macromolécules Végétales of CNRS, affiliated with the Joseph Fourier University of Grenoble, BP 53, 38041 Grenoble Cedex 9, France, Southern Regional Research Center, United States Department of Agriculture, 1100 Robert E. Lee Boulevard, New Orleans, Louisiana 70124, Partnership for Structural Biology, Institute Laue Langevin, 6 Rue Jules Horowitz, F-38042 Grenoble, France, EPSAM/ISTM, Keele University, Keele, Staffordshire ST5 5BG, England, and Bioscience Division, Los
| | - Paul Langan
- Centre de Recherches sur les Macromolécules Végétales of CNRS, affiliated with the Joseph Fourier University of Grenoble, BP 53, 38041 Grenoble Cedex 9, France, Southern Regional Research Center, United States Department of Agriculture, 1100 Robert E. Lee Boulevard, New Orleans, Louisiana 70124, Partnership for Structural Biology, Institute Laue Langevin, 6 Rue Jules Horowitz, F-38042 Grenoble, France, EPSAM/ISTM, Keele University, Keele, Staffordshire ST5 5BG, England, and Bioscience Division, Los
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Lefèvre T, Boudreault S, Cloutier C, Pézolet M. Conformational and orientational transformation of silk proteins in the major ampullate gland of Nephila clavipes spiders. Biomacromolecules 2008; 9:2399-407. [PMID: 18702545 DOI: 10.1021/bm800390j] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The orientational and conformational transformation of the native liquid silk into a solid fiber in the major ampullate gland of the spider Nephila clavipes has been studied by Raman spectromicroscopy. The spectra show that the conformation of silk proteins in the glandular sac contains several secondary structure elements, which is consistent with intrinsically unfolded proteins. A few alpha-helices are also present and involve some alanine residues located in the polyalanine segments of the spidroin sequence. The conversion of the silk solution in the major ampullate gland appears to be a two-state process without intermediate states. In the first and second limbs of the duct, silk is isotropic and spidroins are generally native-like. beta-Sheets start to develop between the second and the third limb of the duct, suggesting that early beta-sheets are generated by shear forces. However, most of the beta-sheets are formed between the draw down taper and the valve. The early beta-sheets formed upward of the draw down taper might play the role of nucleation sites for the subsequent beta-sheet aggregation. The alignment of the polypeptides chains occurs near the valve, revealing that orientational and conformational changes do not occur simultaneously. Extensional flow seems to be the driving force to produce the orientational order, which in turn is associated with the formation of the major part of the beta-sheets. The slow evolution of the spidroin conformation up to the draw down taper followed by the rapid transformation between the drawn down taper and the valve may be important to achieve the optimal structure of the final fiber.
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Affiliation(s)
- Thierry Lefèvre
- Departement de Chimie-CERSIM-CREFSIP, Universite Laval, Pavillon Alexandre-Vachon, Quebec G1V0A6, Canada
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40
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Zhang S, Koziol KKK, Kinloch IA, Windle AH. Macroscopic fibers of well-aligned carbon nanotubes by wet spinning. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2008; 4:1217-1222. [PMID: 18666161 DOI: 10.1002/smll.200700998] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A simple process to spin fibers consisting of multi-walled carbon nanotubes (CNTs) directly from their lyotropic liquid-crystalline phase is reported. Ethylene glycol is used as the lyotropic solvent, enabling a wider range of CNT types to be spun than previously. Fibers spun with CNTs and nitrogen-doped CNTs are compared. X-ray analysis reveals that nitrogen-doped CNTs have a misalignment of only +/-7.8 degrees to the fiber axis. The tensile strength of the CNT and nitrogen-doped CNT fibers is comparable but the modulus and electrical conductivity of the are lower. The electrical conductivity of both types of CNT fibers is found to be highly anisotropic. The results are discussed in context of the microstructure of the CNTs and fibers.
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Affiliation(s)
- Shanju Zhang
- Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB23QZ, UK
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41
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Glišović A, Vehoff T, Davies RJ, Salditt T. Strain Dependent Structural Changes of Spider Dragline Silk. Macromolecules 2007. [DOI: 10.1021/ma070528p] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Anja Glišović
- Institut für Röntgenphysik, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany, and 2 ESRF, 6 Rue Jules Horowitz, BP220, 38043 Grenoble Cedex, France
| | - Thorsten Vehoff
- Institut für Röntgenphysik, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany, and 2 ESRF, 6 Rue Jules Horowitz, BP220, 38043 Grenoble Cedex, France
| | - Richard J. Davies
- Institut für Röntgenphysik, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany, and 2 ESRF, 6 Rue Jules Horowitz, BP220, 38043 Grenoble Cedex, France
| | - Tim Salditt
- Institut für Röntgenphysik, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany, and 2 ESRF, 6 Rue Jules Horowitz, BP220, 38043 Grenoble Cedex, France
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42
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Martel A, Burghammer M, Davies RJ, Riekel C. Thermal Behavior of Bombyx mori Silk: Evolution of Crystalline Parameters, Molecular Structure, and Mechanical Properties. Biomacromolecules 2007. [DOI: 10.1021/bm700935w er] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- A. Martel
- European Synchrotron Radiation Facility, B.P. 220, F-38043 Grenoble Cedex, France
| | - M. Burghammer
- European Synchrotron Radiation Facility, B.P. 220, F-38043 Grenoble Cedex, France
| | - R. J. Davies
- European Synchrotron Radiation Facility, B.P. 220, F-38043 Grenoble Cedex, France
| | - C. Riekel
- European Synchrotron Radiation Facility, B.P. 220, F-38043 Grenoble Cedex, France
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43
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Martel A, Burghammer M, Davies RJ, Riekel C. Thermal behavior of Bombyx mori silk: evolution of crystalline parameters, molecular structure, and mechanical properties. Biomacromolecules 2007; 8:3548-56. [PMID: 17949104 DOI: 10.1021/bm700935w] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The thermal behavior up to degradation of Bombyx mori silk has been studied by scanning synchrotron radiation microdiffraction, gel electrophoresis, and mechanical testing. The diffraction patterns from single baves can be separated into scattering from anisotropic crystalline beta-sheet domains and random short-range order. In contrast to dragline silk, scattering from oriented, short-range-order fibroin is not observed. The sheath of sericin proteins can be selectively probed by a microbeam and shows also principally random short-range-order domains with a small crystalline beta-sheet fraction. Microdiffraction experiments on single baves from 100 to 573 K show an increase in lattice expansion along the [010] chain-stacking direction above 200-250 K, which could be due to an increase in side-chain mobility. Degradation of the crystalline fraction commences at approximately 500 K, and the fibers have become amorphous at about 570 K with an onset of carbonization. Gel electrophoresis shows that the degradation of FibH molecules starts already at about 350 K, while FibL molecules start degrading at about 400 K. The mechanical properties of single baves such as strain-to-failure and tensile strength also start degrading at about 400 K, while the initial modulus increases up to about 475 K. It is proposed that this is due to the development of cross-linking in the short-range-order chain fraction.
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Affiliation(s)
- A Martel
- European Synchrotron Radiation Facility, Grenoble Cedex, France
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44
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Papadopoulos P, Sölter J, Kremer F. Structure-property relationships in major ampullate spider silk as deduced from polarized FTIR spectroscopy. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2007; 24:193-199. [PMID: 17985073 DOI: 10.1140/epje/i2007-10229-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2007] [Accepted: 10/12/2007] [Indexed: 05/25/2023]
Abstract
Polarized Fourier Transform Infrared (FTIR) spectroscopy is employed to study structure-property relationships in major ampullate spider silk being exposed to an external mechanical strain. From the measured infrared dichroism of aminoacid-residue - specific bands the molecular order parameter, the frequency width at half-maximum (FWHM) and the spectral position of the absorption maximum are determined in dependence on the external strain. For the highly ordered alanine-rich beta sheets a change in the vibrational potential is found for macroscopic strains as low as a few percent. It can be quantitatively described by a quantum-mechanical approach in which the mechanical strain is treated as a weak external perturbation. The immediate microscopic response to the external field proves that beta -sheeted crystals are tightly interconnected by pre-stretched chains as suggested recently (Y. Liu et al., Nat. Mater. 4, 901 (2005)).
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Affiliation(s)
- P Papadopoulos
- Institut für Experimentelle Physik I, Universität Leipzig, Leipzig, Germany.
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45
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Vehoff T, Glisović A, Schollmeyer H, Zippelius A, Salditt T. Mechanical properties of spider dragline silk: humidity, hysteresis, and relaxation. Biophys J 2007; 93:4425-32. [PMID: 17766337 PMCID: PMC2098708 DOI: 10.1529/biophysj.106.099309] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Spider silk is well-known for its outstanding mechanical properties. However, there is a significant variation of these properties in literature and studies analyzing large numbers of silk samples to explain these variations are still lacking. To fill this gap, the following work examines the mechanical properties of major ampullate silk based on a large ensemble of threads from Nephila clavipes and Nephila senegalensis. In addition, the effect of relative humidity (RH) on the mechanical properties was quantified. The large effect of RH on the mechanical properties makes it plausible that the variation in the literature values can to a large extent be attributed to changes in RH. Spider silk's most remarkable property-its high tenacity-remains unchanged. In addition, this work also includes hysteresis as well as relaxation measurements. It is found that the relaxation process is well described by a stretched exponential decay.
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Affiliation(s)
- T Vehoff
- Institute for X-Ray Physics, University of Göttingen, Göttingen, Germany
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46
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Drummy LF, Farmer BL, Naik RR. Correlation of the β-sheet crystal size in silk fibers with the protein amino acid sequence. SOFT MATTER 2007; 3:877-882. [PMID: 32900081 DOI: 10.1039/b701220a] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Low voltage transmission electron microscopy (LVTEM) and wide angle X-ray scattering (WAXS) are used to independently determine the size of the β-sheet crystalline regions in Bombyx mori silk fibers. The peak in the size distributions of the major and minor axes of the anisotropic crystallites measured from the LVTEM images compare well with the average sizes as determined by Scherrer analysis of the X-ray fiber diagrams. These values are then discussed in the context of the B. mori fibroin heavy chain amino acid sequence, and the underlying mechanism for the organism's control on fiber crystallite size, and therefore mechanical properties, is proposed.
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Affiliation(s)
| | - B L Farmer
- 3005 Hobson Way, Wright Patterson Air Force Base, OH 45433, USA.
| | - Rajesh R Naik
- 3005 Hobson Way, Wright Patterson Air Force Base, OH 45433, USA.
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Rousseau ME, Hernández Cruz D, West MM, Hitchcock AP, Pézolet M. Nephila clavipes Spider Dragline Silk Microstructure Studied by Scanning Transmission X-ray Microscopy. J Am Chem Soc 2007; 129:3897-905. [PMID: 17352470 DOI: 10.1021/ja067471r] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Nephila clavipes dragline silk microstructure has been investigated by scanning transmission X-ray microscopy (STXM), a technique that allows quantitative mapping of the level of orientation of the peptide groups at high spatial resolution (<50 nm). Maps of the orientation parameter P2 have been derived for spider silk for the first time. Dragline silk presents a very fine microstructure in which small, highly oriented domains (average area of 1800 nm2, thus clearly bigger than individual beta-sheet crystallites) are dispersed in a dominant, moderately oriented matrix with several small unoriented domains. Our results also highlight the orientation of the noncrystalline fraction in silk, which has been underestimated in numerous structural models. No evidence of either a regular lamellar structure or any periodicity along the fiber was observed at this spatial resolution. The surface of fresh spider silk sections consists of a approximately 30-120 nm thick layer of highly oriented protein chains, which was found to vary with the reeling speed, where web building (0.5 cm/s) and lifeline (10 cm/s) spinning speeds were investigated. While the average level of orientation of the protein chains is unaffected by the spinning speed, STXM measurements clearly highlight microstructure differences. The slowpull fiber contains a larger fraction of highly oriented domains, while the protein chains are more homogeneously oriented in the fastpull fiber. In comparison, cocoon silk from the silkworm Bombyx mori presents a narrower orientation distribution. The strength-extensibility combination found in spider dragline silk is associated with its broad orientation distribution of highly interdigitated and unoriented domains.
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Affiliation(s)
- Marie-Eve Rousseau
- CERSIM, CREFSIP, Département de Chimie, Université Laval, Québec, Canada G1K 7P4
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48
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Marcotte I, van Beek JD, Meier BH. Molecular Disorder and Structure of Spider Dragline Silk Investigated by Two-Dimensional Solid-State NMR Spectroscopy. Macromolecules 2007. [DOI: 10.1021/ma062452n] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | | | - Beat H. Meier
- Physical Chemistry, ETH Zurich, CH-8093 Zurich, Switzerland
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49
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Lefèvre T, Rousseau ME, Pézolet M. Protein secondary structure and orientation in silk as revealed by Raman spectromicroscopy. Biophys J 2007; 92:2885-95. [PMID: 17277183 PMCID: PMC1831708 DOI: 10.1529/biophysj.106.100339] [Citation(s) in RCA: 251] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Taking advantage of recent advances in polarized Raman microspectroscopy, and based on a rational decomposition of the amide I band, the conformation and orientation of proteins have been determined for cocoon silks of the silkworms Bombyx mori and Samia cynthia ricini and dragline silks of the spiders Nephila clavipes and Nephila edulis. This study distinguished between band components due to beta-sheets, beta-turns, 3(1)-helices, and unordered structure for the four fibers. For B. mori, the beta-sheet content is 50%, which matches the proportion of residues that form the GAGAGS fibroin motifs. For the Nephila dragline and S. c. ricini cocoon, the beta-sheet content (36-37% and 45%, respectively) is higher than the proportion of residues that belong to polyalanine blocks (18% and 42%, respectively), showing that adjacent GGA motifs are incorporated into the beta-sheets. Nephila spidroins contain fewer beta-sheets and more flexible secondary structures than silkworm fibroins. The amorphous polypeptide chains are preferentially aligned parallel to the fiber direction, although their level of orientation is much lower than that of beta-sheets. Overall, the results show that the four silks exhibit a common molecular organization, with mixtures of different amounts of beta-sheets and flexible structures, which are organized with specific orientation levels.
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Affiliation(s)
- Thierry Lefèvre
- Centre de Recherche en Sciences et Ingénierie des Macromolécules, Centre de Recherche sur la Fonction, la Structure et l'Ingénierie des Protéines, Département de Chimie, Université Laval, Pavillon Alexandre-Vachon, Québec, Canada
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50
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Seydel T, Kölln K, Krasnov I, Diddens I, Hauptmann N, Helms G, Ogurreck M, Kang SG, Koza MM, Müller M. Silkworm Silk under Tensile Strain Investigated by Synchrotron X-ray Diffraction and Neutron Spectroscopy. Macromolecules 2007. [DOI: 10.1021/ma0624189] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Tilo Seydel
- Institut Laue-Langevin, B.P. 156, F-38042 Grenoble, France, and IEAP, University of Kiel, Olshausenstrasse 40, D-24098 Kiel, Germany
| | - Klaas Kölln
- Institut Laue-Langevin, B.P. 156, F-38042 Grenoble, France, and IEAP, University of Kiel, Olshausenstrasse 40, D-24098 Kiel, Germany
| | - Igor Krasnov
- Institut Laue-Langevin, B.P. 156, F-38042 Grenoble, France, and IEAP, University of Kiel, Olshausenstrasse 40, D-24098 Kiel, Germany
| | - Imke Diddens
- Institut Laue-Langevin, B.P. 156, F-38042 Grenoble, France, and IEAP, University of Kiel, Olshausenstrasse 40, D-24098 Kiel, Germany
| | - Nadine Hauptmann
- Institut Laue-Langevin, B.P. 156, F-38042 Grenoble, France, and IEAP, University of Kiel, Olshausenstrasse 40, D-24098 Kiel, Germany
| | - Gesa Helms
- Institut Laue-Langevin, B.P. 156, F-38042 Grenoble, France, and IEAP, University of Kiel, Olshausenstrasse 40, D-24098 Kiel, Germany
| | - Malte Ogurreck
- Institut Laue-Langevin, B.P. 156, F-38042 Grenoble, France, and IEAP, University of Kiel, Olshausenstrasse 40, D-24098 Kiel, Germany
| | - Shin-Gyu Kang
- Institut Laue-Langevin, B.P. 156, F-38042 Grenoble, France, and IEAP, University of Kiel, Olshausenstrasse 40, D-24098 Kiel, Germany
| | - Michael M. Koza
- Institut Laue-Langevin, B.P. 156, F-38042 Grenoble, France, and IEAP, University of Kiel, Olshausenstrasse 40, D-24098 Kiel, Germany
| | - Martin Müller
- Institut Laue-Langevin, B.P. 156, F-38042 Grenoble, France, and IEAP, University of Kiel, Olshausenstrasse 40, D-24098 Kiel, Germany
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