Skip to main content Accessibility help

Viscoelastic relaxation time and structural evolution during length contraction of spider silk protein nanostructures

  • Graham Bratzel (a1), Zhao Qin (a2) and Markus J. Buehler (a2)


Spider dragline silk is a self-assembling protein that rivals many engineering fibers in strength, extensibility, and toughness, making it a versatile biocompatible material. Here, atomistic-level structures of wildtype MaSp1 protein from the Nephila clavipes spider dragline silk sequences, obtained using an in silico approach based on replica exchange molecular dynamics and explicit water, are subjected to nanomechanical testing and released preceding failure. We approximate the relaxation time from an exponential decay function, and identify permanent changes in secondary structure. Our work provides fundamental insights into the time-dependent properties of silk and possibly other protein materials.


Corresponding author

Address all correspondence to Markus J. Buehler at


Hide All
1.Vollrath, F. and Knight, D.P.: Liquid crystalline spinning of spider silk. Nature 410, 541548 (2001).
2.Becker, N., Oroudjev, E., Mutz, S., Cleveland, J.P., Hansma, P.K., Hayashi, C.Y., Makarov, D.E., and Hansma, H.G.: Molecular nanosprings in spider capture-silk threads. Nat. Mater. 2, 278283 (2003).
3.Shao, Z.Z. and Vollrath, F.: Materials: surprising strength of silkworm silk. Nature 418, 741741 (2002).
4.Simmons, A.H., Michal, C.A., and Jelinski, L.W.: Molecular orientation and two-component nature of the crystalline fraction of spider dragline silk. Science 271, 8487 (1996).
5.Termonia, Y.: Molecular modeling of spider silk elasticity. Macromolecules 27, 73787381 (1994).
6.Hayashi, C.Y., Shipley, N.H., and Lewis, R.V.: Hypotheses that correlate the sequence, structure, and mechanical properties of spider silk proteins. Int. J. Biol. Macromol. 24, 271275 (1999).
7.Gatesy, J., Hayashi, C., Motriuk, D., Woods, J., and Lewis, R.: Extreme diversity, conservation, and convergence of spider silk fibroin sequences. Science 291, 26032605 (2001).
8.Gosline, J.M., Guerette, P.A., Ortlepp, C.S., and Savage, K.N.: The mechanical design of spider silks: from fibroin sequence to mechanical function. J. Exp. Biol. 202, 32953303 (1999).
9.Brooks, A.E., Steinkraus, H.B., Nelson, S.R., and Lewis, R.V.: An investigation of the divergence of major ampullate silk fibers from Nephila clavipes and Argiope aurantia. Biomacromolecules 6, 30953099 (2005).
10.Holland, G.P., Creager, M.S., Jenkins, J.E., Lewis, R.V., and Yarger, J.L.: Determining secondary structure in spider dragline silk by carbon-carbon correlation solid-state NMR spectroscopy. J. Am. Chem. Soc. 130, 98719877 (2008).
11.Bratzel, G.H. and Buehler, M.J.: Sequence-structure correlations in silk: Poly-Ala repeat of N. clavipes MaSp1 is naturally optimized at a critical length scale. J. Mech. Behav. Biomed. Mater 7, 3040 (2011).
12.Keten, S. and Buehler, M.J.: Nanostructure and molecular mechanics of spider dragline silk protein assemblies. J. R. Soc. Interface 7, 17091721 (2010).
13.Keten, S. and Buehler, M.J.: Atomistic model of the spider silk nanostructure. Appl. Phy. Lett. 96, 153701 (2011).
14.Keten, S., Xu, Z., Ihle, B., and Buehler, M.J.: Nanoconfinement controls stiffness, strength and mechanical toughness of beta-sheet crystals in silk. Nat. Mater. 9, 359367 (2010).
15.Lefevre, T., Rousseau, M.E., and Pezolet, M.: Protein secondary structure and orientation in silk as revealed by Raman spectromicroscopy. Biophys. J. 92, 28852895 (2007).
16.Thiel, B.L., Guess, K.B., and Viney, C.: Non-periodic lattice crystals in the hierarchical microstructure of spider (major ampullate) silk. Biopolymers 41, 703719 (1997).
17.van Beek, J.D., Hess, S., Vollrath, F., and Meier, B.H.: The molecular structure of spider dragline silk: folding and orientation of the protein backbone. Proc. Natl. Acad. Sci. USA 99, 1026610271 (2002).
18.Bratzel, G.H. and Buehler, M.J.: Molecular mechanics of silk nanostructures under varied mechanical loading. Biopolymers 97, 408417 (2012).
19.Kinahan, M.E., Filippidi, E., Ko"ster, S., Hu, X., Evans, H.M., Pfohl, T., Kaplan, D.L., and Wong:, J.Tunable silk: using microfluidics to fabricate silk fibers with controllable properties. Biomacromolecules 12, 15041511 (2011).
20.Krishnaji, S.T., Bratzel, G.H., Kinahan, M.E., Kluge, J.A., Staii, C., Wong, J.Y., Buehler, M.J., and Kaplan, D.L.: Sequence–structure–property relationships of recombinant spider silk proteins: integration of biopolymer design, processing, and modeling. Adv. Funct. Mater. 23, 241253 (2013).
21.Humphrey, W., Dalke, A., and Schulten, K.: VMD—visual molecular dynamics. J. Mol. Graphics 14, 3338 (1996).
22.Ruiz, L., VonAchen, P., Lazzara, T.D., Xu, T., and Keten, S.: Persistence length and stochastic fragmentation of supramolecular nanotubes under mechanical force. Nanotechnology 24, 195103 (2013).
23.Qin, Z., Gautieri, A., Nair, A.K., Inbar, H., and Buehler, M.J.: Thickness of hydroxyapatite nanocrystal controls mechanical properties of the collagen-hydroxyapatite interface. Langmuir 28, 19821992 (2012).


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed