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Crystal structure of human common-type acylphosphatase and insights into enzyme-substrate interaction.

Yeung, Ching Yee. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 112-122). / Abstracts in English and Chinese. / Acknowledgments --- p.I / Abstract --- p.II / 摘要 --- p.III / Content --- p.IV / Abbreviations and symbols --- p.XI / List of tables and figures --- p.XV / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Acylphosphatase --- p.1 / Chapter 1.2 --- Human acylphosphatase --- p.4 / Chapter 1.3 --- Hyperthermophilic Pyrococcus horikoshii acylphosphatase --- p.5 / Chapter 1.4 --- Human common-type acylphosphatase as a mesophilic homologue of Pyrococcus horikoshii acylphosphatase --- p.8 / Chapter 1.5 --- Enzyme-substrate interaction of acylphosphatase --- p.9 / Chapter Chapter 2 --- Materials and methods --- p.10 / Chapter 2.1 --- Preparation of Escherichia coli competent cells --- p.10 / Chapter 2.2 --- SDS-polyacrylamide gel electrophoresis --- p.11 / Chapter 2.2.1 --- Preparation of polyacrylamide gel --- p.11 / Chapter 2.2.2 --- SDS-polyacrylamide gel electrophoresis (SDS-PAGE) --- p.12 / Chapter 2.2.3 --- Staining of protein in polyacrylamide gel by Coommassie Brillant Blue R250 --- p.12 / Chapter 2.3 --- Expression and purification of Protein --- p.13 / Chapter 2.3.1 --- "General bacterial culture, harvesting and lysis" --- p.13 / Chapter 2.3.2 --- Purification of acylphosphatase --- p.14 / Chapter 2.3.2.1 --- Ion-exchange chromatography --- p.14 / Chapter 2.3.2.2 --- Size excision chromatography --- p.15 / Chapter 2.3.3 --- Protein concentration determination --- p.16 / Chapter 2.4 --- X-ray crystallography --- p.17 / Chapter 2.4.1 --- Crystallization of Hu CT AcP --- p.17 / Chapter 2.4.2 --- Model building and structural refinement --- p.18 / Chapter 2.4.3 --- Crystallization of Hu CT AcP -substate analogue complex --- p.19 / Chapter 2.5 --- Enzymatic Assay --- p.21 / Chapter 2.5.1 --- Preparation of benzoyl phosphate --- p.21 / Chapter 2.5.2 --- Purity check of the BP synthesized --- p.22 / Chapter 2.5.3 --- Determination of kinetic parameters of Hu CT AcP --- p.25 / Chapter 2.5.4 --- Determination of Ki value of substrate analogue --- p.27 / Chapter 2.6 --- Isothermal titration calorimetry --- p.28 / Chapter 2.7 --- Reagents and Buffers --- p.30 / Chapter 2.7.1 --- Reagent for competent cell preparation --- p.30 / Chapter 2.7.2 --- Media for bacterial culture --- p.31 / Chapter 2.7.3 --- Reagent for SDS-PAGE --- p.32 / Chapter 2.7.4 --- Buffer for AcP purification --- p.33 / Chapter 2.7.5 --- Buffer for enzymatic assay and ITC --- p.33 / Chapter Chapter 3 --- Structural determination of human common-type acylphosphatase --- p.34 / Chapter 3.1 --- Introduction --- p.34 / Chapter 3.2 --- Expression and purification of Hu CT AcP --- p.35 / Chapter 3.3 --- Structure of Hu CT AcP was determined by X-ray crystallography --- p.37 / Chapter 3.3.1 --- Crystallization of Hu CT AcP --- p.37 / Chapter 3.3.2 --- Model building and structural refinement --- p.41 / Chapter 3.3.3 --- Hu CT AcP shares a same α/β sandwich fold structure as other AcP --- p.43 / Chapter 3.4 --- Discussion --- p.46 / Chapter 3.4.1 --- Active site structure of Hu CT AcP is the same as those of bovine CT AcP and Ph AcP --- p.46 / Chapter 3.4.2 --- Absence of salt bridge between the active site residue and the C-terminal may contribute to the higher catalytic efficiency of Hu CT AcP --- p.52 / Chapter Chapter 4 --- Characterization of interaction between acylphosphatase and substrate analogues --- p.56 / Chapter 4.1 --- Introduction --- p.56 / Chapter 4.2 --- Selected substrate analogues --- p.57 / Chapter 4.3 --- Characterization of AcP-substrate analogue interaction by enzymatic assay --- p.59 / Chapter 4.3.1 --- Enzyme kinetics of Hu CT AcP was determined by the continuous optical assay of BP hydrolysis --- p.59 / Chapter 4.3.2 --- Substrate analogues were found to be competitive inhibitor to the AcP-catalyzed BP hydrolysis --- p.61 / Chapter 4.3.3 --- S-BA was the best competitive inhibitor against AcP-catalyzed BP hydrolysis --- p.64 / Chapter 4.3.4 --- S-BA was shown to be a competitive inhibitor for both Hu CT and Ph AcP --- p.66 / Chapter 4.4 --- Characterization of AcP-substrate analogue interaction by thermodynamic study --- p.68 / Chapter 4.4.1 --- Enthalpy change was observed for the association between substrate analogue and AcP --- p.68 / Chapter 4.4.2 --- S-BA was shown to bind Hu CT AcP with high affinity in ITC study --- p.68 / Chapter 4.5 --- S-BA was found to be the best substrate analogue for AcP --- p.72 / Chapter 4.6 --- Discussion --- p.73 / Chapter 4.6.1 --- Structure-affinity study of substrate analogue reveals chemical structures essential to interaction with AcP --- p.73 / Chapter 4.6.2 --- Structure-affinity study of substrate analogues is consistent with docking model of AcP with acetyl phosphate --- p.75 / Chapter 4.6.3 --- Validation of docking model by crystal complex structure --- p.78 / Chapter 4.6.4 --- Structural basis of substrate inhibition in Hu CT AcP --- p.80 / Chapter 4.6.4.1 --- Substrate inhibition is observed in Hu CT AcP --- p.80 / Chapter 4.6.4.2 --- Non-productive binding and substrate inhibition in AcP --- p.80 / Chapter Chapter 5 --- Investigation on the effect of salt bridge on acylphosphatase- substrate analogue interaction --- p.84 / Chapter 5.1 --- Introduction --- p.84 / Chapter 5.2 --- Thermodynamic study on the binding of S-BA with AcPs --- p.87 / Chapter 5.2.1 --- Determination of thermodynamic parameters of interaction between AcP and substrate analogue --- p.87 / Chapter 5.2.2 --- Determination of thermodynamic parameters as a function of temperature --- p.90 / Chapter 5.3 --- Discussion --- p.93 / Chapter 5.3.1 --- The presence of salt bridge leads to a reduced flexibility at the substrate binding active site --- p.93 / Chapter 5.3.2 --- The single salt bridge reduces the flexibility of active site in both study on thermodynamics of binding and thermodynamics of activation --- p.94 / Chapter 5.3.3 --- Temperature dependence of the thermodynamic parameters and heat capacity change ΔCp --- p.97 / Chapter 5.3.3.1 --- Change in heat capacity reveals the nature of the complex interface --- p.97 / Chapter 5.3.3.2 --- Determination of heat capacity change ΔCp --- p.98 / Chapter Chapter 6 --- Structural determination of acylphosphatase-substrate analogue complex --- p.102 / Chapter 6.1 --- Introduction --- p.102 / Chapter 6.2 --- Soaking and cocrystallization failed to give cocrystal structure of Hu CT AcP and S-BA --- p.103 / Chapter 6.4 --- Discussion --- p.106 / Chapter 6.4.1 --- Hu CT AcP and S-BA is not compatible with cocrystal formation --- p.106 / Chapter 6.5 --- Future prospect --- p.107 / Chapter 6.5.1 --- Structure determination by NMR spectroscopy --- p.107 / Chapter 6.5.2 --- Structure determination of AcP with aluminofluoride complexes --- p.108 / Chapter Chapter 7 --- Conclusion --- p.109 / Reference --- p.112

Identiferoai:union.ndltd.org:cuhk.edu.hk/oai:cuhk-dr:cuhk_326563
Date January 2008
ContributorsYeung, Ching Yee., Chinese University of Hong Kong Graduate School. Division of Biochemistry.
Source SetsThe Chinese University of Hong Kong
LanguageEnglish, Chinese
Detected LanguageEnglish
TypeText, bibliography
Formatprint, xvi, 122 leaves : ill. (some col.) ; 30 cm.
RightsUse of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/)

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