View source for 1gaz


==Crystal Structure of Mutant Human Lysozyme Substituted at the Surface Positions==
<StructureSection load='1gaz' size='340' side='right'caption='[[1gaz]], [[Resolution|resolution]] 1.80&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1gaz]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1GAZ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1GAZ FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.8&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=NA:SODIUM+ION'>NA</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1gaz FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1gaz OCA], [https://pdbe.org/1gaz PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1gaz RCSB], [https://www.ebi.ac.uk/pdbsum/1gaz PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1gaz ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/LYSC_HUMAN LYSC_HUMAN] Defects in LYZ are a cause of amyloidosis type 8 (AMYL8) [MIM:[https://omim.org/entry/105200 105200]; also known as systemic non-neuropathic amyloidosis or Ostertag-type amyloidosis. AMYL8 is a hereditary generalized amyloidosis due to deposition of apolipoprotein A1, fibrinogen and lysozyme amyloids. Viscera are particularly affected. There is no involvement of the nervous system. Clinical features include renal amyloidosis resulting in nephrotic syndrome, arterial hypertension, hepatosplenomegaly, cholestasis, petechial skin rash.<ref>PMID:8464497</ref> 
== Function ==
[https://www.uniprot.org/uniprot/LYSC_HUMAN LYSC_HUMAN] Lysozymes have primarily a bacteriolytic function; those in tissues and body fluids are associated with the monocyte-macrophage system and enhance the activity of immunoagents.
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/ga/1gaz_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1gaz ConSurf].
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== Publication Abstract from PubMed ==
To clarify the role of amino acid residues at turns in the conformational stability and folding of a globular protein, six mutant human lysozymes deleted or substituted at turn structures were investigated by calorimetry, GuHCl denaturation experiments, and X-ray crystal analysis. The thermodynamic properties of the mutant and wild-type human lysozymes were compared and discussed on the basis of their three-dimensional structures. For the deletion mutants, Delta47-48 and Delta101, the deleted residues are in turns on the surface and are absent in human alpha-lactalbumin, which is homologous to human lysozyme in amino acid sequence and tertiary structure. The stability of both mutants would be expected to increase due to a decrease in conformational entropy in the denatured state; however, both proteins were destabilized. The destabilizations were mainly caused by the disappearance of intramolecular hydrogen bonds. Each part deleted was recovered by the turn region like the alpha-lactalbumin structure, but there were differences in the main-chain conformation of the turn between each deletion mutant and alpha-lactalbumin even if the loop length was the same. For the point mutants, R50G, Q58G, H78G, and G37Q, the main-chain conformations of these substitution residues located in turns adopt a left-handed helical region in the wild-type structure. It is thought that the left-handed non-Gly residue has unfavorable conformational energy compared to the left-handed Gly residue. Q58G was stabilized, but the others had little effect on the stability. The structural analysis revealed that the turns could rearrange the main-chain conformation to accommodate the left-handed non-Gly residues. The present results indicate that turn structures are able to change their main-chain conformations, depending upon the side-chain features of amino acid residues on the turns. Furthermore, stopped-flow GuHCl denaturation experiments on the six mutants were performed. The effects of mutations on unfolding-refolding kinetics were significantly different among the mutant proteins. The deletion/substitutions in turns located in the alpha-domain of human lysozyme affected the refolding rate, indicating the contribution of turn structures to the folding of a globular protein.

Role of amino acid residues at turns in the conformational stability and folding of human lysozyme.,Takano K, Yamagata Y, Yutani K Biochemistry. 2000 Jul 25;39(29):8655-65. PMID:10913274<ref>PMID:10913274</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 1gaz" style="background-color:#fffaf0;"></div>

==See Also==
*[[Lysozyme 3D structures|Lysozyme 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Funahashi J]]
[[Category: Takano K]]
[[Category: Yamagata Y]]
[[Category: Yutani K]]