1yap
CONTRIBUTION OF HYDROPHOBIC RESIDUES TO THE STABILITY OF HUMAN LYSOZYME: CALORIMETRIC STUDIES AND X-RAY STRUCTURAL ANALYSIS OF THE FIVE ISOLEUCINE TO VALINE MUTANTS
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OverviewOverview
In order to understand the contribution of hydrophobic residues to the, conformational stability of human lysozyme, five Ile mutants (Ile --> Val), in the interior of the protein were constructed. The thermodynamic, parameters characterizing the denaturation of these mutant proteins were, determined by scanning calorimetry, and the three-dimensional structure of, each mutant protein was solved at high resolution by X-ray, crystallography. The thermodynamic analyses at 64.9 degrees C and at pH, 2.7 revealed the following. (1) The stabilities of all the mutant proteins, were decreased as compared with that of the wild-type protein. (2) The, changes in the calorimetric enthalpies were larger than those in the Gibbs, energies, and were compensated by entropy changes. (3) The destabilization, mechanism of the mutant proteins differs, depending on the location of the, mutation sites. X-ray analyses showed that the overall structures of all, the mutant human lysozymes examined were identical to that of the, wild-type protein, and only small structural rearrangements were observed, locally around some of the mutation sites. The most striking change among, the mutant proteins was found in the mutant protein, 159V, which contains, a new water molecule in the cavity created by the mutation. The, thermodynamic stabilities of the mutant proteins are discussed in light of, the high-resolution X-ray structures of the wild-type and five mutant, human lysozymes examined.
DiseaseDisease
Known diseases associated with this structure: Amyloidosis, renal OMIM:[153450], Microphthalmia, syndromic 1 OMIM:[309800]
About this StructureAbout this Structure
1YAP 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
Contribution of hydrophobic residues to the stability of human lysozyme: calorimetric studies and X-ray structural analysis of the five isoleucine to valine mutants., Takano K, Ogasahara K, Kaneda H, Yamagata Y, Fujii S, Kanaya E, Kikuchi M, Oobatake M, Yutani K, J Mol Biol. 1995 Nov 17;254(1):62-76. PMID:7473760
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