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PDBsum entry 1gxv
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Contents |
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* Residue conservation analysis
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References listed in PDB file
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Key reference
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Title
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Pressure-Dependent changes in the solution structure of hen egg-White lysozyme.
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Authors
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M.Refaee,
T.Tezuka,
K.Akasaka,
M.P.Williamson.
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Ref.
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J Mol Biol, 2003,
327,
857-865.
[DOI no: ]
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PubMed id
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Abstract
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The "rules" governing protein structure and stability are still poorly
understood. Important clues have come from proteins that operate under extreme
conditions, because these clarify the physical constraints on proteins. One
obvious extreme is pressure, but so far little is known of the behavior of
proteins under pressure, largely for technical reasons. We have therefore
developed new methodology for calculating structure change in solution with
pressure, using NMR chemical shift changes, and we report the change in
structure of lysozyme on going from 30 bar to 2000 bar, this being the first
solution structure of a globular protein under pressure. The alpha-helical
domain is compressed by approximately 1%, due to tighter packing between
helices. The interdomain region is also compressed. By contrast, the beta-sheet
domain displays very little overall compression, but undergoes more structural
distortion than the alpha-domain. The largest volume changes tend to occur close
to hydrated cavities. Because isothermal compressibility is related to volume
fluctuation, this suggests that buried water molecules play an important role in
conformational fluctuation at normal pressures, and are implicated as the
nucleation sites for structural changes leading to pressure denaturation or
channel opening.
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Figure 2.
Figure 2. Test for motion about hinge axis. Histogram of
rotation (change in th, high pressure -low pressure) around the
38-97 axis, for all heavy atoms. A unimodal distribution
indicates no hinge bending.
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Figure 5.
Figure 5. Distance from C^a atom to nearest buried water
molecule, plotted against absolute change in amino acid Voronoi
volume,[38.] for all completely buried atoms. Only residues with
volume change greater than 2 Å3 are shown. Compression is
shown in red, and expansion in black.
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The above figures are
reprinted
by permission from Elsevier:
J Mol Biol
(2003,
327,
857-865)
copyright 2003.
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