1c46
MUTANT HUMAN LYSOZYME WITH FOREIGN N-TERMINAL RESIDUES
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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
1C46 is a Single protein structure of sequence from Homo sapiens. 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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