Blog
About

5
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: not found

      Structural characterisation of the human alpha-lactalbumin molten globule at high temperature.

      Journal of Molecular Biology

      Circular Dichroism, Temperature, Spectrometry, Fluorescence, Protein Structure, Secondary, Protein Folding, Models, Molecular, Magnetic Resonance Spectroscopy, chemistry, Lactalbumin, Kinetics, Hydrogen-Ion Concentration, Humans

      Read this article at

      ScienceOpenPubMed
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Molten globules are partially folded forms of proteins thought to be general intermediates in protein folding. The 15N-1H HSQC NMR spectrum of the human alpha-lactalbumin (alpha-LA) molten globule at pH 2 and 20 degrees C is characterised by broad lines which make direct study by NMR methods difficult; this broadening arises from conformational fluctuations throughout the protein on a millisecond to microsecond timescale. Here, we find that an increase in temperature to 50 degrees C leads to a dramatic sharpening of peaks in the 15N-1H HSQC spectrum of human alpha-LA at pH 2. Far-UV CD and ANS fluorescence experiments demonstrate that under these conditions human alpha-LA maintains a high degree of helical secondary structure and the exposed hydrophobic surfaces that are characteristic of a molten globule. Analysis of the H(alpha), H(N) and 15N chemical shifts of the human alpha-LA molten globule at 50 degrees C leads to the identification of regions of native-like helix in the alpha-domain and of non-native helical propensity in the beta-domain. The latter may be responsible for the observed overshoot in ellipticity at 222 nm in kinetic refolding experiments.

          Related collections

          Author and article information

          Journal
          12860137

          Comments

          Comment on this article