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Self-Assembly of a Modular Polypeptide based on Blocks of Silk-Mimetic and ElastinMimetic Sequences

Published online by Cambridge University Press:  01 February 2011

Chrystelle S. Cazalis  and
Vincent P. Conticello
Chrystelle S. Cazalis
Affiliation:
Department of Chemistry, Emory University, Atlanta, GA 30322
Vincent P. Conticello
Affiliation:
Department of Chemistry, Emory University, Atlanta, GA 30322
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Abstract

Spider dragline silk fiber displays a unique and technologically significant combination of high tensile and compressive strength. The structural origin of these properties arises from the alternating sequence of crystalline alanine-rich domains and amorphous glycine-rich domains, which undergo microscopic phase separation in the silk fiber. We previously reported the synthesis and the self-assembly of a novel polypeptide 1, which emulates the modular structure of crystalline and amorphous elastomeric domains in dragline silk proteins. The sequence of this polypeptide comprises an alternating arrangement of a self-complementary, amphiphilic silk-mimetic oligopeptide (Ala-Glu-Ala-Glu-Ala-Lys-Ala-Lys) and environmentally-responsive elastin-mimetic segment (Val-Pro-Gly-Val-Gly). We report herein the synthesis and the self-assembly of an analogous polypeptide (2) with an higher content of elastin mimetic pentapeptides. A synthetic gene encoding four repeats of the alternating sequence was expressed in E. coli strain BL21(DE3) as a C-terminal fusion to a decahistidine leader sequence to afford a polypeptide with a molar mass of approximately 39 kDa. The regularly alternating pattern of elastin-mimetic and silk-mimetic blocks within the protein allowed the copolymer to spontaneously self-assemble upon heating above the phase transition of the elastin-mimetic block. The self-assembly process was studied using a combination of CD and solid-state NMR spectroscopy, which suggested that the alanine-rich domains undergo a conformational rearrangement from α-helix to β-sheet. This rearrangement coincides with the macromolecular phase transition of the elastin-mimetic domains, which resulted in irreversible aggregation of the polypeptide above the Tt of the elastin-mimetic domains.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 724: Symposium N – Biological and Biomimetic Materials Properties to Function , 2002 , N3.8
Copyright
Copyright © Materials Research Society 2002

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References

1. Jelinski, L. W., Biomaterials, 3, 237(1998)Google Scholar
2. (a) Beckwwitt, R., Arcidiacono, S., Stote, R., Insect Biochem. Mol. Biol., 28, 121 (1998).Google Scholar
(b) Guerette, P. A., Ginzinger, D. G., Weber, B. H. F., Gosline, J. M., Science, 272, 112 (1996).Google Scholar
3. (a) Hijirida, D. H., Do, K. G., Wong, S., Zax, D., Jelinski, L. W., Biophys. J., 71, 3442, (1996).Google Scholar
(b) Simmons, A. H., Michal, C. A., Jelinski, L. W., Science, 271, 84 (1996).Google Scholar
(c) Simmons, A. H., Ray, E., Jelinski, L. W., Macromolecules, 27, 5235 (1994).Google Scholar
4. Michal, C.A., Jelinski, L. W., J. Biomol. NMR 12, 231(1998).Google Scholar
5. Grubb, D. T., Jelinski, L. W., Macromolecules, 30, 2860 (1997).Google Scholar
6. Termonia, Y., Macromolecules, 27, 7378 (1994).Google Scholar
7. Warwicker, J. O., J. Mol. Biol., 2, 350 (1960).Google Scholar
8. Hayashi, C. Y., Shipley, N. H., Lewis, R. V., Int. J. Biol. Macromol., 24 271(1999).Google Scholar
9. Qu, Y., Payne, S. C., Apkarian, R. P., Conticello, V. P., J. Am. Chem. Soc., 122, 5014 (2000)Google Scholar
10. Cazalis, C., Conticello, V. P., Abstr. Pap. Am. Chem. Soc. 211: 591-PMSE Part 2 (2001).Google Scholar
11. Urry, D. W., Trapane, T. L., Prasad, K. U., Biopolymers, 24, 2345 (1985).Google Scholar
12. Marky, L. A., Breslauer, K. J., Biopolymers, 26, 1601 (1987).Google Scholar
13. Johnson, C. W. Jr, Proteins, 7, 205 (1990)Google Scholar
14. Saito, H., J. Biomol. NMR, 5, 67 (1995).Google Scholar