Classification de points critiques de cartes de densité électronique de protéines à moyenne résolution

  • John Biname

    Student thesis: Master typesMaster in Chemistry

    Abstract

    The aim of this study was to highlight criteria for the identification of amino acids in the interpretation of experimental protein electron density maps. Our work was based on the study of several descriptors of the critical points of the electron density maps. These critical points were issued from the topological analysis by CCRIT of electronic density maps, of selected proteins, generated by XTAL with a crystallographic resolution equal to 3 Å. We have associated the critical points to either a backbone or a sidechain region. Next, we standardised the critical point descriptors to apply a cluster analysis procedure. We concluded from this analysis that the cystein and methionin sidechains can be identified on the basis of such an interpretation. The determination of a protein structure on the basis of the critical points of its electronic density map should be carried out through a hierarchical process. In such a process, the presence of critical points associated to amino acid sidechains will first be determined. Then cystein and methionine sidechains will be localized. Finally, other amino acid residues would be identified through the consideration of the environment of each critical point.
    Date of Award2000
    Original languageFrench
    SupervisorDaniel Vercauteren (Supervisor)

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