Structure and pH-induced alterations of recombinant and natural spider silk proteins in solution

Authors

  • Jérémie Leclerc,

    1. Department of Chemistry, Regroupement québécois de recherche sur la fonction, la structure et l'ingénierie des protéines (PROTEO), Centre de recherche sur les matériaux avancés (CERMA), QC G1V 0A6, Canada
    Search for more papers by this author
  • Thierry Lefèvre,

    1. Department of Chemistry, Regroupement québécois de recherche sur la fonction, la structure et l'ingénierie des protéines (PROTEO), Centre de recherche sur les matériaux avancés (CERMA), QC G1V 0A6, Canada
    Search for more papers by this author
  • Fabien Pottier,

    1. Department of Chemistry, Regroupement québécois de recherche sur la fonction, la structure et l'ingénierie des protéines (PROTEO), Centre de recherche sur les matériaux avancés (CERMA), QC G1V 0A6, Canada
    Search for more papers by this author
  • Louis-Philippe Morency,

    1. Department of Chemistry, Regroupement québécois de recherche sur la fonction, la structure et l'ingénierie des protéines (PROTEO), Centre de recherche sur les matériaux avancés (CERMA), QC G1V 0A6, Canada
    Search for more papers by this author
  • Camille Lapointe-Verreault,

    1. Department of Chemistry, Regroupement québécois de recherche sur la fonction, la structure et l'ingénierie des protéines (PROTEO), Centre de recherche sur les matériaux avancés (CERMA), QC G1V 0A6, Canada
    Search for more papers by this author
  • Stéphane M. Gagné,

    1. Department of Biochemistry, Microbiology and Bioinformatics, Regroupement québécois de recherche sur la fonction, la structure et l'ingénierie des protéines (PROTEO), Université Laval, QC G1V 0A6, Canada
    Search for more papers by this author
  • Michèle Auger

    Corresponding author
    1. Department of Chemistry, Regroupement québécois de recherche sur la fonction, la structure et l'ingénierie des protéines (PROTEO), Centre de recherche sur les matériaux avancés (CERMA), QC G1V 0A6, Canada
    • Department of Chemistry, Regroupement québécois de recherche sur la fonction, la structure et l'ingénierie des protéines (PROTEO), Centre de recherche sur les matériaux avancés (CERMA), QC G1V 0A6, Canada
    Search for more papers by this author

  • This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com

Abstract

The spinning process of spiders can modulate the mechanical properties of their silk fibers. It is therefore of primary importance to understand what are the key elements of the spider spinning process to develop efficient industrial spinning processes. We have exhaustively investigated the native conformation of major ampullate silk (MaS) proteins by comparing the content of the major ampullate gland of Nephila clavipes, solubilized MaS (SolMaS) fibers and the recombinant proteins rMaSpI and rMaSpII using 1H solution NMR spectroscopy. The results indicate that the protein secondary structure is basically identical for the recombinant protein rMaSpI, SolMaS proteins, and the proteins in the dope, and corresponds to a disordered protein rich in 31-helices. The data also show that glycine proton chemical shifts of rMaSpI and SolMaS are affected by pH, but that this change is not due to a modification of the secondary structure. Using a combination of NMR and dynamic light scattering, we have found that the spectral alteration of glycine is concomitant to a modification of the hydrodynamical diameter of recombinant and solubilized MaS. This led us to suggest new potential roles for the pH acidification in the spinning process of MaS proteins. © 2011 Wiley Periodicals, Inc. Biopolymers 97: 337–346, 2012.

Ancillary