1c45: Difference between revisions
New page: left|200px<br /> <applet load="1c45" size="450" color="white" frame="true" align="right" spinBox="true" caption="1c45, resolution 1.8Å" /> '''MUTANT HUMAN LYSOZYM... |
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[[Image:1c45.gif|left|200px]]<br /> | [[Image:1c45.gif|left|200px]]<br /><applet load="1c45" size="350" color="white" frame="true" align="right" spinBox="true" | ||
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caption="1c45, resolution 1.8Å" /> | caption="1c45, resolution 1.8Å" /> | ||
'''MUTANT HUMAN LYSOZYME WITH FOREIGN N-TERMINAL RESIDUES'''<br /> | '''MUTANT HUMAN LYSOZYME WITH FOREIGN N-TERMINAL RESIDUES'''<br /> | ||
==Overview== | ==Overview== | ||
To minutely understand the effect of foreign N-terminal residues on the | To minutely understand the effect of foreign N-terminal residues on the conformational stability of human lysozyme, five mutant proteins were constructed: two had Met or Ala in place of the N-terminal Lys residue (K1M and K1A, respectively), and others had one additional residue, Met, Gly or Pro, to the N-terminal Lys residue (Met(-1), Gly(-1) and Pro(-1), respectively). The thermodynamic parameters for denaturation of these mutant proteins were examined by differential scanning calorimetry and were compared with that of the wild-type protein. Three mutants with the extra residue were significantly destabilized: the changes in unfolding Gibbs energy (DeltaDeltaG) were -9.1 to -12.2 kJ.mol-1. However, the stability of two single substitutions at the N-terminal slightly decreased; the DeltaDeltaG values were only -0.5 to -2.5 kJ.mol-1. The results indicate that human lysozyme is destabilized by an expanded N-terminal residue. The crystal structural analyses of K1M, K1A and Gly(-1) revealed that the introduction of a residue at the N-terminal of human lysozyme caused the destruction of hydrogen bond networks with ordered water molecules, resulting in the destabilization of the protein. | ||
==Disease== | ==Disease== | ||
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==About this Structure== | ==About this Structure== | ||
1C45 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with NA as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [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] Full crystallographic information is available from [http:// | 1C45 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with <scene name='pdbligand=NA:'>NA</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [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] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1C45 OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: stability]] | [[Category: stability]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:02:11 2008'' |
Revision as of 13:02, 21 February 2008
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MUTANT HUMAN LYSOZYME WITH FOREIGN N-TERMINAL RESIDUES
OverviewOverview
To minutely understand the effect of foreign N-terminal residues on the conformational stability of human lysozyme, five mutant proteins were constructed: two had Met or Ala in place of the N-terminal Lys residue (K1M and K1A, respectively), and others had one additional residue, Met, Gly or Pro, to the N-terminal Lys residue (Met(-1), Gly(-1) and Pro(-1), respectively). The thermodynamic parameters for denaturation of these mutant proteins were examined by differential scanning calorimetry and were compared with that of the wild-type protein. Three mutants with the extra residue were significantly destabilized: the changes in unfolding Gibbs energy (DeltaDeltaG) were -9.1 to -12.2 kJ.mol-1. However, the stability of two single substitutions at the N-terminal slightly decreased; the DeltaDeltaG values were only -0.5 to -2.5 kJ.mol-1. The results indicate that human lysozyme is destabilized by an expanded N-terminal residue. The crystal structural analyses of K1M, K1A and Gly(-1) revealed that the introduction of a residue at the N-terminal of human lysozyme caused the destruction of hydrogen bond networks with ordered water molecules, resulting in the destabilization of the protein.
DiseaseDisease
Known diseases associated with this structure: Amyloidosis, renal OMIM:[153450], Microphthalmia, syndromic 1 OMIM:[309800]
About this StructureAbout this Structure
1C45 is a Single protein structure of sequence from Homo sapiens with as ligand. Active as Lysozyme, with EC number 3.2.1.17 Full crystallographic information is available from OCA.
ReferenceReference
Effect of foreign N-terminal residues on the conformational stability of human lysozyme., Takano K, Tsuchimori K, Yamagata Y, Yutani K, Eur J Biochem. 1999 Dec;266(2):675-82. PMID:10561612
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