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Structural characterization of a highly–ordered ‘molten globule’ at low pH

Nature Structural & Molecular Biologyvolume 1pages2329 (1994) | Download Citation



The characterization of unfolded and partly folded states of proteins is central to understanding protein stability and folding, as well as providing a basis for protein design. The four helix bundle–protein interleukin–4 undergoes an unfolding transition at low pH. Using heteronuclear nuclear magnetic resonance methods we show that following this transition the protein retains a highly ordered hydrophobic core in which most, but not all, of the secondary structure is preserved. Extensive disorder exists, however, in regions of polypeptide chain linking the structural elements which make up this core. We suggest that this ‘highly ordered molten globule’ could be indicative of the type of structures occurring late in protein folding processes, in contrast to more disordered ‘molten globules’ which relate to early folding intermediates.

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  1. Oxford Centre for Molecular Sciences and New Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, OX1 3QT, UK

    • Christina Redfield
    •  & Christopher M. Dobson
  2. SmithKline Beecham Pharmaceuticals, The Pinnacles, Coldharbour Road, Harlow, CM19 5AD, UK

    • Richard A.G. Smith


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