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1eqe

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Revision as of 07:08, 20 December 2017

CRYSTAL STRUCTURES OF SALT BRIDGE MUTANTS OF HUMAN LYSOZYME

Structural highlights

1eqe is a 1 chain structure with sequence from Human. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:
Related:	1c43, 1eq4, 1eq5
Activity:	Lysozyme, with EC number 3.2.1.17
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Disease

[LYSC_HUMAN] Defects in LYZ are a cause of amyloidosis type 8 (AMYL8) [MIM: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.^[1]

Function

[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

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

Salt bridges play important roles in the conformational stability of proteins. However, the effect of a surface salt bridge on the stability remains controversial even today; some reports have shown little contribution of a surface salt bridge to stability, whereas others have shown a favorable contribution. In this study, to elucidate the net contribution of a surface salt bridge to the conformational stability of a protein, systematic mutant human lysozymes, containing one Glu to Gln (E7Q) and five Asp to Asn mutations (D18N, D49N, D67N, D102N, and D120N) at residues where a salt bridge is formed near the surface in the wild-type structure, were examined. The thermodynamic parameters for denaturation between pH 2.0 and 4.8 were determined by use of a differential scanning calorimeter, and the crystal structures were analyzed by X-ray crystallography. The denaturation Gibbs energy (DeltaG) of all mutant proteins was lower than that of the wild-type protein at pH 4, whereas there was little difference between them near pH 2. This is caused by the fact that the Glu and Asp residues are ionized at pH 4 but protonated at pH 2, indicating a favorable contribution of salt bridges to the wild-type structure at pH 4. Each contribution was not equivalent, but we found that the contributions correlate with the solvent inaccessibility of the salt bridges; the salt bridge contribution was small when 100% accessible, while it was about 9 kJ/mol if 100% inaccessible. This conclusion indicates how to reconcile a number of conflicting reports about role of surface salt bridges in protein stability. Furthermore, the effect of salts on surface salt bridges was also examined. In the presence of 0.2 M KCl, the stability at pH 4 decreased, and the differences in stability between the wild-type and mutant proteins were smaller than those in the absence of salts, indicating the compensation to the contribution of salt bridges with salts. Salt bridges with more than 50% accessibility did not contribute to the stability in the presence of 0.2 M KCl.

Contribution of salt bridges near the surface of a protein to the conformational stability.,Takano K, Tsuchimori K, Yamagata Y, Yutani K Biochemistry. 2000 Oct 10;39(40):12375-81. PMID:11015217^[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Pepys MB, Hawkins PN, Booth DR, Vigushin DM, Tennent GA, Soutar AK, Totty N, Nguyen O, Blake CC, Terry CJ, et al.. Human lysozyme gene mutations cause hereditary systemic amyloidosis. Nature. 1993 Apr 8;362(6420):553-7. PMID:8464497 doi:http://dx.doi.org/10.1038/362553a0
↑ Takano K, Tsuchimori K, Yamagata Y, Yutani K. Contribution of salt bridges near the surface of a protein to the conformational stability. Biochemistry. 2000 Oct 10;39(40):12375-81. PMID:11015217

1 Structural highlights
2 Disease
3 Function
4 Evolutionary Conservation
5 Publication Abstract from PubMed
6 See Also
7 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/1eqe"

@@ Line 1: / Line 1: @@
 ==CRYSTAL STRUCTURES OF SALT BRIDGE MUTANTS OF HUMAN LYSOZYME==
 <StructureSection load='1eqe' size='340' side='right' caption='[[1eqe]], [[Resolution|resolution]] 1.80&Aring;' scene=''>
@@ Line 6: / Line 7: @@
 <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1c43|1c43]], [[1eq4|1eq4]], [[1eq5|1eq5]]</td></tr>
 <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Lysozyme Lysozyme], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.17 3.2.1.17] </span></td></tr>
-<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1eqe FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1eqe OCA], [http://pdbe.org/1eqe PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1eqe RCSB], [http://www.ebi.ac.uk/pdbsum/1eqe PDBsum]</span></td></tr>
+<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1eqe FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1eqe OCA], [http://pdbe.org/1eqe PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1eqe RCSB], [http://www.ebi.ac.uk/pdbsum/1eqe PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1eqe ProSAT]</span></td></tr>
 </table>
 == Disease ==
@@ Line 16: / Line 17: @@
 Check<jmol>
   <jmolCheckbox>
-    <scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/eq/1eqe_consurf.spt"</scriptWhenChecked>
+    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/eq/1eqe_consurf.spt"</scriptWhenChecked>
     <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
     <text>to colour the structure by Evolutionary Conservation</text>

1eqe

From Proteopedia

Revision as of 07:08, 20 December 2017

CRYSTAL STRUCTURES OF SALT BRIDGE MUTANTS OF HUMAN LYSOZYME

Structural highlights

Disease

Function

Evolutionary Conservation

Publication Abstract from PubMed

See Also

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

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