Native disulfide bonds greatly accelerate secondary structure formation in the folding of lysozyme

Authors

  • Michel E. Goldberg,

    Corresponding author
    1. Unité de Biochimie Cellulaire, CNRS URA 1129, Institut Pasteur, 28 rue du Dr. Roux, 75724 Paris Cedex 15, France
    • Unité de Biochimie Cellulaire, CNRS URA 1129, Institut Pasteur, 28 rue du Dr. Roux, 75724 Paris Cedex 15, France; e-mail: goldberg@pasteur.fr
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  • Yvonne Guillou

    1. Unité de Biochimie Cellulaire, CNRS URA 1129, Institut Pasteur, 28 rue du Dr. Roux, 75724 Paris Cedex 15, France
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Abstract

To assess the respective roles of local and long-range interactions during protein folding, the influence of the native disulfide bonds on the early formation of secondary structure was investigated using continuous-flow circular dichroism. Within the first 4 ms of folding, lysozyme with intact disulfide bonds already had a far-UV CD spectrum reflecting large amounts of secondary structure. Conversely, reduced lysozyme remained essentially unfolded at this early folding time. Thus, native disulfide bonds not only stabilize the final conformation of lysozyme but also provide, in early folding intermediates, the necessary stabilization that favors the formation of secondary structure.

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