Thèses sur le sujet « Metal binding sites »
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Gapian, Bianké Jean-Paul. « DNA mimics containing artificial metal-binding sites / ». [S.l.] : [s.n.], 2006. http://www.zb.unibe.ch/download/eldiss/06bianke_g.pdf.
Texte intégralTorrance, James William. « The geometry and evolution of catalytic sites and metal binding sites ». Thesis, University of Cambridge, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.612125.
Texte intégralHiggins, Sean. « The design of conducting polymers with metal binding sites ». Thesis, University of St Andrews, 1998. http://hdl.handle.net/10023/14786.
Texte intégralGregory, David St John. « Prediction, design and characterisation of metal binding sites in antibodies ». Thesis, University of Oxford, 1992. https://ora.ox.ac.uk/objects/uuid:630ede76-2db6-4e59-bdbe-d337d4fe07a9.
Texte intégralHannan, Jonathan Paul. « NMR spectroscopic studies of transition metal binding sites in metalloproteins ». Thesis, University of East Anglia, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.323296.
Texte intégralUppal, Daljit Kaur. « Studies of the metal-binding sites in macrocyclic quadridentate ligands ». Thesis, London Metropolitan University, 1986. http://repository.londonmet.ac.uk/3284/.
Texte intégralJeong, Chang-Yoon. « Modelling metal competition for adsorption sites on humic acid ». Thesis, University of Nottingham, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389363.
Texte intégralMcMahon, Jennifer Nicole. « Heavy metal competition for acid volatile sulfide binding sites in southeastern coastal sediments ». Thesis, Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/19134.
Texte intégralYang, Ying. « Mechanism of metal delivery and binding to transport sites of Cu+-transporting ATPases ». Link to electronic thesis, 2005. http://www.wpi.edu/Pubs/ETD/Available/etd-042905-112044/.
Texte intégralLazarides, Theodore. « Luminescent d-block metal polypyridyl complexes bearing secondary macrocyclic or non-macrocyclic binding sites ». Thesis, University of Sheffield, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.427184.
Texte intégralChandrasekar, Sowmya. « Probing metal and substrate binding to metallo-[beta]-lactamase ImiS from Aeromonas sobria using site-directed mutagenesis ». Oxford, Ohio : Miami University, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=miami1098134311.
Texte intégralKeech, Angus Miles. « Role of cobalt(II) and manganese(II) as optical and magnetic probes of metal binding sites in proteins ». Thesis, University of East Anglia, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389267.
Texte intégralPrasannan, Charulata Bhaskaran. « Modulation of restriction enzyme PvuII activity by metal ion cofactors ». Diss., St. Louis, Mo. : University of Missouri--St. Louis, 2009. http://etd.umsl.edu/r4461.
Texte intégralOw, Yang Giselle Bei. « EXAFS structural analysis on metal binding sites in wood pulp and a brief study on chelation of metals in bleaching ». Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/7087.
Texte intégralHaas, Marco. « A synthetic approach to asymmetric phthalocyanines with peripheral metal-binding sites and their divalent Ruthenium complexes / ». [S.l.] : [s.n.], 2006. http://www.zb.unibe.ch/download/eldiss/06haas_m.pdf.
Texte intégralSoebbing, Samantha Lynn. « Incorporation of histidine-rich metal-binding sites onto small protein scaffolds implications for imaging, therapeutics, and catalysis / ». Diss., University of Iowa, 2008. http://ir.uiowa.edu/etd/37.
Texte intégralSchweitzer, Dirk. « Biomimetic models of the active site of the metalloenzyme nitrile hydratase / ». Thesis, Connect to this title online ; UW restricted, 2001. http://hdl.handle.net/1773/8692.
Texte intégralWenzel, Nathan F. « Glyoxalase 2-2 over-expression and characterization of a metallohydrolase from Arabidopsis thaliana / ». Oxford, Ohio : Miami University, 2003. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=miami1069728340.
Texte intégralTitle from first page of PDF document. Document formatted into pages; contains xii, 83 p. : ill. Includes bibliographical references.
Roy, Choudhury Shamali. « Mapping of metal ion binding sites in the RecBCD enzyme and the role of magnesium in the subunit interactions of RecBCD ». College Park, Md. : University of Maryland, 2006. http://hdl.handle.net/1903/3360.
Texte intégralThesis research directed by: Biochemistry. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
Rehmani, Imran J. « Studying the DNA Binding and Conformation of Metal-Binding Site Mutations in Pirin ». Digital Archive @ GSU, 2012. http://digitalarchive.gsu.edu/chemistry_theses/53.
Texte intégralEyley, J. E. « Gas sorption and binding site studies in metal organic frameworks ». Thesis, University of Nottingham, 2017. http://eprints.nottingham.ac.uk/40546/.
Texte intégralMongeau, Raymond. « Antidepressant and anxiolytic action on the Serotonin1A binding site ». Thesis, McGill University, 1990. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=59934.
Texte intégralLee, Hsiau-Wei. « Determining The Site Specific Metal Binding and Structural Properties of EF-Hand Protein Using Grafting Approach ». Digital Archive @ GSU, 2008. http://digitalarchive.gsu.edu/chemistry_diss/26.
Texte intégralLuo, Yujia. « Analgesic Effect of Nicotine and Exploration of Binding Sites for α4β2 Nicotinic Acetylcholine Receptor Positive Allosteric Modulators ». Thesis, The University of Sydney, 2023. https://hdl.handle.net/2123/30000.
Texte intégralChandrasekar, Sowmya. « Probing Metal and Substrate Binding to Metallo-β-Lactamase ImiS from Aeromonas Sobria using Site-Directed Mutagenesis ». Miami University / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=miami1098134311.
Texte intégralZhao, Kun. « Mathematical Methods for Network Analysis, Proteomics and Disease Prevention ». Digital Archive @ GSU, 2012. http://digitalarchive.gsu.edu/math_diss/6.
Texte intégralChen, Yinghua. « Solution structure of the target recognition domain of zoocin A, an antibacterial enzyme, and the metal binding site of zoocin A ». Thesis, [Tuscaloosa, Ala. : University of Alabama Libraries], 2009. http://purl.lib.ua.edu/2202.
Texte intégralKreibich, Julian. « Mechanistic insights into carbon monoxide and CoA binding at the Ni,Ni-[4Fe-4S] active site of the acetyl-CoA synthase from Carboxydothermus hydrogenoformans ». Doctoral thesis, Humboldt-Universität zu Berlin, 2021. http://dx.doi.org/10.18452/23215.
Texte intégralThe acetyl-CoA synthase (ACS) harbors a unique metal cluster (cluster A) in its active site, which is important for bacteria and archaea to survive in autotrophic growth using the reductive acetyl-CoA. The last step of this pathway is catalyzed by ACS at the Nip, the Ni ion proximal to the [4Fe-4S] cluster. In my study, the monomeric ACS of Carboxydothermus hydrogenoformans (ACSCh) was studied in its ligand binding and crystallized in different forms. At first, an ACSCh structure was solved in a new conformation at dmin of 2.1 Å and less solvent exposed (called ACSCh-closed) than the known structure of ACSCh (called ACSCh-open, PDB-ID:1RU3). The cluster A of ACSCh-closed differs to that of ACSCh-open in the coordination of the proximal Ni, which is distorted tetrahedrally coordinated in ACSCh-closed and square planar coordinated in ACSCh-open. Analysis of the model revealed a molecular tunnel that is only present in ACSCh-closed, which might act as CO channel for substrate delivery. Secondly, a CO-bound ACSCh-closed crystal was obtained and solved at a resolution of 2.0 Å. An electron density fitting with a diatomic ligand at the Nip site was clearly identified and modeled as a CO molecule. CO binds at the Nip site completing the tetrahedral coordination geometry of Nip. The conformational switch between open and closed is responsible for CO migration and binding to the catalytic site. A third crystal structure depicts a CoA bound ACSCh structure at 2.3 Å resolution. CoA binds at the Nip which shows a square planar geometry. This was further supported by calculating different electron density maps for CoA. The binding of CO and CoA to ACSCh has been characterized by isothermal calorimetry experiments. While CoA binding is enthalpically driven with a KD of 3.1 µM, CO binds to ACSCh by entropic contribution with a KD of 9.4 µM.
Houwaart, Torsten. « Cobalt porphyrins on coinage metal surfaces - adsorption and template properties ». Thesis, Lyon, École normale supérieure, 2014. http://www.theses.fr/2014ENSL0927.
Texte intégralThis thesis is a theoretical study on the cobalt porphyrin - coinage metal surface interface with the DFT code VASP. The necessary DFT framework has been introduced in chapter 1. The structure of the Java program jBardeen for STM simulation is explained in chapter 2 and the source code is attached as Appendix. A study of the adsorption of CoTPP on coinage metal surfaces has been undertaken in chapter 3. Different parameters of the calculation have been evaluated: the adsorption site and the geometry of both the molecule and surface have been investigated with respect to the xc-functional and dispersion correction used. A most stable adsorption site -bridge down- is identified. Consequently, this most stable site was investigated for its electronic structure. Calculated STM images with the jBardeen code were compared with an experiment of CoTPP on a Cu(111) surface with sub monolayer coverage. In chapter 4 an Fe adatom was introduced to the CoTPP on Ag(111) system. Three symmetrically different binding sites for the Fe atom were identified on the macrocycle, labelled the bi-, brd- and bru-positions for bisector, bridge down and bridge up respectively. A magnetic moment could be evidenced which was mainly located on the Fe atom. Possible pathways between the four symmetrically equivalent bisector sites were investigated with different methods. Single point calculations in vacuum and Nudged Elastic Band (NEB) of the whole system revealed a barrier height of slightly above 0.2 eV going from bi- to the brd-position. A vibrational analysis showed that switching of the Fe atom is likely, when perturbed out of equilibrium in the brd- and bru- positions
López, Muñoz Laura. « Homology modeling and structural analysis of the antipsychotic drugs receptorome ». Doctoral thesis, Universitat Pompeu Fabra, 2010. http://hdl.handle.net/10803/7228.
Texte intégralThe study started with obtaining homology models for all the receptors putatively involved in the antipsychotic drugs receptorome, suitable for building consistent drug-receptor complexes. These complexes were structurally analyzed and compared using multivariate statistical methods, which in turn allowed the identification of the relationship between the pharmacological properties of the antipsychotic drugs and the structural differences in the receptor targets. The results can be exploited for the design of safer and more effective antipsychotic drugs with an optimum binding profile.
Tradicionalmente se asumía que los fármacos terapéuticamente efectivos actuaban interaccionando con un único receptor. Actualmente está ampliamente reconocido que el efecto farmacológico de la mayoría de los fármacos es más complejo y abarca a un conjunto de receptores, algunos asociados a los efectos terapéuticos y otros a los secundarios y toxicidad. Los fármacos antipsicóticos son un ejemplo de compuestos eficaces que se caracterizan por unirse a varios receptores simultáneamente (principalmente a receptores unidos a proteína G, GPCR). El trabajo de la presente tesis se ha centrado en el estudio de los mecanismos moleculares que determinan el perfil de afinidad de unión por múltiples receptores de los fármacos antipsicóticos.
En primer lugar se construyeron modelos de homología para todos los receptores potencialmente implicados en la actividad farmacológica de dichos fármacos, usando una metodología adecuada para construir complejos fármaco-receptor consistentes. La estructura de estos complejos fue analizada y se llevó a cabo una comparación mediante métodos estadísticos multivariantes, que permitió la identificación de asociaciones entre la actividad farmacológica de los fármacos antipsicóticos y diferencias estructurales de los receptores diana. Los resultados obtenidos tienen interés para ser explotados en el diseño de fármacos antipsicóticos con un perfil farmacológico óptimo, más seguros y eficaces.
Lin, Yu-Feng, et 林玉鳳. « Prediction of metal binding sites in proteins ». Thesis, 2010. http://ndltd.ncl.edu.tw/handle/86030438365561006913.
Texte intégral中國醫藥大學
分子系統生物醫學研究所
98
The biochemical functions of proteins are determined upon the structure of the polypeptide and the interaction of cofactors. The functional surfaces of proteins, which interact with ligands, substrates, or proteins, tend to be more conserved in sequence and structure pattern, and the residues of a functional binding region are usually spatial close in three-dimensional structure. Recently, there are more than sixty thousand structures in Protein Data Bank (PDB), and a large amount of proteins, about one-third of proteins, is considered binding to metal ions. Large parts of metal ions in human body are bound to proteins, and metal ions are very important to implement the functions of metalloproteins. However, the subsequent experimental method to localize metal binding sites is time-consuming and costly, so that many computational methods had been developed for indentifying metal binding sites. Most computational methods are based on sequence information; therefore, we proceeded to our investigation of metal binding sites by using sequence and structural information. In this study, six kinds of metal ions (Calcium, Copper, Iron, Magnesium, Manganese, Zinc) binding residues had been constructed, and then gathered as metal-binding residue templates, which are metal binding residues spherical within 3.5Å around the site of interest. By taking advantage of the fragment transformation method, the comparison of structures was carrying out. According to the sequence and structure conservation of interaction sites, we can combine both structural and sequence information to identify the local structure protein-metal interaction sites. In the results, the prediction performance of a 94.6% Q2 accuracy with a 60.5% TPR at a 5% FPR can be achieved.
Li, Jyn-Han, et 李居翰. « MIB : a Metal Ion–Binding sites prediction tool ». Thesis, 2015. http://ndltd.ncl.edu.tw/handle/8rn739.
Texte intégralYang, Tzung Yin, et 楊宗穎. « Mononuclear versus Binuclear Metal-Binding Sites : Metal Binding Affinity and Selectivity from PDB Survey and DFT/CDM Calculations ». Thesis, 2007. http://ndltd.ncl.edu.tw/handle/09710750216292499288.
Texte intégral國立清華大學
化學系
95
Binuclear metal centers in metalloenzymes are involved in a number of hydrolytic, hydration, isomerization, and redox processes. Despite the growing number of studies elucidating their structure, properties, and function, questions regarding certain aspects of the bimetallic proteins’ biochemistry still remain; e.g., (i) What are the general characteristics of binuclear sites found in 3D structures such as the range of metal訃metal distances, and the most common ligand bridging the two metal cations? (ii) How does the presence of a metal cation in one of the binuclear sites affect the metal訃binding affinity/selectivity of the other site? (iii) How do the characteristics and metal訃binding affinity/selectivity of binuclear sites compare with those of their mononuclear counterparts? Here we address these questions by combining a Protein Data Bank survey of binuclear sites with density functional theory (DFT) combined with continuum dielectric method (CDM) calculations. The results reveal that for homo訃binuclear sites, the metal separation depends on the metal’s charge and the electron-accepting ability, and Asp-/Glu-, bidentately bound to the two cations, is the most common bridging ligand. They also reveal that Mg2+洶occupying one of the binuclear sites attenuates the metal訃binding affinity, but enhances the selectivity of its neighboring site, compared to the corresponding mononuclear counterparts. These findings are consistent with available experimental data. The weak metal binding of one of the binuclear sites would enhance the metal cofactor mobility in achieving the transition state, whereas the enhanced selectivity of Mg2+訃Mg2+ centers help protect against unwanted substitutions by transition metal ions, which are generally stronger Lewis acids compared to Mg2+.
VALASATAVA, YANA. « NEW COMPUTATIONAL APPROACHES TO THE STUDY OF METALS IN BIOLOGY ». Doctoral thesis, 2015. http://hdl.handle.net/2158/998429.
Texte intégralMazmanian, Karine, et 馬玫霓. « Elucidating the Physicochemical Principles of Regulation in Protein Functional Sites : Free Cysteines and Metal-binding Sites ». Thesis, 2018. http://ndltd.ncl.edu.tw/handle/s2d777.
Texte intégral國立臺灣大學
生化科學研究所
106
Protein activity in the cell is tightly regulated on both cellular and molecular levels. Molecular level involves regulation through creating a local protein environment around a functional site organized for an optimal protein activity. Currently, general physicochemical principles of regulation of local environment of functional sites in proteins remain elusive and in this study, we tried to answer the question of how can interactions of the functionally important residues favor the optimal organization of the local protein environment. As examples of such functional systems, we have chosen free cysteines, zinc and sodium-binding proteins. To address the posed question we modeled the studied functional systems together with their interactions explicitly and implicit solvent with the quantum chemical density functional (QC/DFT) approach. The computational results were complemented with analysis and survey of the available experimental data. Cysteine (Cys) reactivity depends on the protein environment and one of the key contributors to its modulation is the HB interactions. Thus, we assessed the most preferred HB partners of free Cys. As a result, we show that the strength and selectivity of the HB interactions with free Cys ultimately depend on the combination of the extent of HB complex solvation and the properties of Cys HB partner. In this manner, through providing various HBs partners and dielectric environment the protein of interest can modulate the HB strength and consequently the degree of thiolate stabilization, which in turn would affect the cysteine''s nucleophilicity/reactivity. Statistical analysis of free Cys and their local protein environment in the reported crystal structures revealed that in the proteins the HB interactions with Cys are formed according to our predicted HB preferences. In proteins, cysteines are preferred first-shell ligands for zinc (Zn2+), and zinc is readily displaced by toxic cadmium (Cd2+) due to the high affinity of the later for cysteines. Proteins through providing HB interactions between the first- and second-shell ligands regulate and stabilize/protect the metal complex or enhance metal binding properties. Yet, knowledge of the preferred HB partners of metal ligands in different metalloproteins is lacking. We were the first to systematically unravel the principles governing the preferred hydrogen-bonding partners of metal ligands on the example of zinc- and cadmium-thiolate (Cys-) complexes in proteins. It appears that the nature of metal-binding first-shell residues and solvent exposure of the complex determine the HB preferences of the second shell ligands. Upon Zn2+ to Cd2+ substitution, the size difference of the two cations yielded similarities and differences in their protein environment preferences. We conclude that neutral and flexible Zn2+-sites lined by small neutral amino acid (aa) sidechains are more vulnerable for toxic Cd2+ effects as it could distort the native protein structure and thereby alter/abolish the protein function. Similarly to zinc proteins, sodium-binding proteins play diverse important roles in the cell. However the concentration of Na+ and Mg2+ cations are present in comparable amounts in the cytosol, but it is not clear how Na+ and Mg2+ binding sites discriminate the native cation among non-cognate ones from the surrounding milieu and the physical basis governing the selectivity for Na+ over Mg2+. The results, which are consistent with available experimental data, reveal that in proteins, the selectivity for Na+ over Mg2+ in sodium-binding sites stem mainly from the size, charge, and charge-accepting ability differences between Na+ and Mg2+. Next, we studied the competition between native Na+ and abiogenic Li+ in sodium neurotransporters and G-protein coupled receptors (GPCRs). Neurotransmitter transporters and receptors are well-known drug targets for psychiatric disorders and addictive behavior and lithium has been used as a first-line treatment of the number of psychiatric disorders (e.g. depression). We show that rigid Na+-sites that are crowded with multiple protein ligands are well-protected against Li+ attack, but their flexible counterparts or buried Na+-sites containing only one or two protein ligands are vulnerable to Li+ substitution. By displacing Na+ bound to an Asp- and a Ser in the solvent-inaccessible metal-binding sites of the A2AAR adenosine and the 1AR adrenergic GPCRs, Li+ could stabilize the receptor''s inactive state by prohibiting conformational changes to the active state, thus leading to decreased G-protein activity, which are hyperactive in bipolar patients. In our studied model systems, we have demonstrated how key physicochemical factors govern the formation of the optimal local environments around functional sites allowing proteins to regulate their functions. Our results can be broadly applied to artificial protein design, rational drug design, and development of biosensors. We underscore the importance of further investigations of physicochemical local environments of the functional sites and their role in the regulation of protein functions and outline several problems for future investigations.
Switala, Brooke A. « Probing metal binding sites in DNA by using europium(III) luminescence spectroscopy ». 2007. http://proquest.umi.com/pqdweb?did=1441197201&sid=1&Fmt=2&clientId=39334&RQT=309&VName=PQD.
Texte intégralTitle from PDF title page (viewed on June 18, 2008) Available through UMI ProQuest Digital Dissertations. Thesis adviser: Morrow, Janet R. Includes bibliographical references.
Chen, Yu-Kai, et 陳又楷. « Analysis of Complementary Transgenic Arabidopsis and the Metal Binding Sites in Phytochelatin Synthase ». Thesis, 2014. http://ndltd.ncl.edu.tw/handle/47063052983945167425.
Texte intégralPai, Chi-Yi, et 白吉鎰. « Prediction Metal-Binding Sites of Metalloprotein using RBF network and physicochemical properties analysis ». Thesis, 2010. http://ndltd.ncl.edu.tw/handle/96410553233806878376.
Texte intégral元智大學
資訊工程學系
98
Metalloprotein is a Metal and protein binding type of people needed.Some of Metalloproteins that are become Zinc-finger structure,these are Transcription factor with DNA binding for the regulation of gene expression.This is a important regulation organisms,play an important role in biological process. In the experimental difficulties, a further analysis of its binding site, it is very important and useful work, so to develop a predictable and metal ions in protein binding site is an important study. In this experiment the use of QuickRBF classifier predicted protein sequences with the metal binding site, and to use sequence information and some predict the evolution of the physical and chemical properties to predict the protein sequence of cysteine and histidine . In addition also proposed disulfide bond forecasting methods and histidine forecasting methods used to improve QuickRBF predictions. Our forecast performance for cysteine can be achieved Recall 60.3%, Precision 88.8%, while the histidine can be achieved Recall 40.1%, Precision 62.3%
Bridgewater, Juma D. « Using metal catalyzed oxidation reactions and mass spectrometry as a reliable method for determining metal binding-sites in proteins ». 2006. https://scholarworks.umass.edu/dissertations/AAI3242308.
Texte intégral« Insights into the Role of the Metal-Binding Sites of Quercetin 2,3-Dioxygenase from Bacillus subtilis ». Doctoral diss., 2010. http://hdl.handle.net/2286/R.I.8650.
Texte intégralDissertation/Thesis
Ph.D. Biochemistry 2010
Geeganage, Sandaruwan. « Mechanistic analysis of variant galactose-1-phosphate uridylyltransferases incorporating amino acid-mutations in the active and metal binding sites ». 1999. http://catalog.hathitrust.org/api/volumes/oclc/43303261.html.
Texte intégralSui, Meng-Jiun, et 隋孟君. « Characterization of the divalent metal ion and the phosphate ion binding sites in the H-N-H endonulease colicin E7 ». Thesis, 2002. http://ndltd.ncl.edu.tw/handle/56562691591829371051.
Texte intégral國防醫學院
生命科學研究所
91
Colicins are a group of plasmid-encoded protein toxins produced by Escherichia coli to kill other sensitive E. coli and closely related coliform bacteria. The cytotoxic activities of colicins against their target cells are well documented: as an RNase, a DNase, a protein synthesis inhibitor or an ionophore. The subfamily of E-group DNase-type colicins, including colicin E2, E7, E8 and E9, contain an H-N-H motif in the cytotoxic nuclease domain, capable of cleaving DNA nonspecifically. This H-N-H motif was firstly identified in a subfamily of homing endonucleases, which cleave DNA site specifically and initiate a process of transferring a mobile intervening sequence into a homologous allele that lacks the sequence. The H-N-H motif contains two anti-parallel b-strands linked to a C-terminal a-helix, with a divalent metal ion located in the center. It is however not clear how the H-N-H motif mediates its function in DNA binding and hydrolysis. For a better understanding of the role of metal ions in the H-N-H motif during DNA hydrolysis, we crystallized the nuclease domain of colicin E7 in complex with its inhibitor Im7 (nuclease-ColE7/Im7) in two different crystal forms and we resolved the structures of EDTA-treated, Zn2+-bound and Mn2+-bound complexes in the presence of phosphate ions at resolutions of 2.6 to 2.0. Å. The structure study of the EDTA-treated nuclease-ColE7/Im7 offers the first determination of the structure of a metal-free and substrate-free enzyme in the H-N-H family. We showed that the metal-binding sites in the center of the H-N-H motif, for the EDTA-treated and Mg2+-soaked complex crystals, were occupied by water molecules, indicating that an alkaline earth metal ion does not reside in the same position as a transition metal ion in H-N-H motif. However a Zn2+ or Mn2+ ions were observed in the center of the H-N-H motif in cases of Zn2+ or Mn2+-soaked crystals, as confirmed in anomalous difference maps. A phosphate ion was found to bridge between the divalent transition metal ion and His545. Based on these structures and structural comparisons with other nucleases, we suggest a functional role for the divalent transition metal ion in the H-N-H motif in stabilizing the phosphoanion in the transition state during hydrolysis. We also construct a structural model for the nuclease-ColE7 bound to DNA and propose a mechanism for DNA hydrolysis catatalyzed by the H-N-H endonucleases.
Bilder, Patrick Wallace. « The structural diversity of metal binding sites in bacterial metalloproteins : the disordered iron-binding coil of iron-sulfur cluster protein A and the stable zinc ribbon motif of the carboxyltransferase subunit of acetyl-coa carboxylase ». Diss., 2005. http://etd.library.vanderbilt.edu/ETD-db/available/etd-01222006-213113/.
Texte intégralDias, Alistair Vincent Michael. « The control and utilization of Ni(II) in Escherichia coli : The Ni(II)-specific response of NikR and the characterization of the metal-binding sites of HypB ». 2009. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=968401&T=F.
Texte intégralAzizan, Nur. « Study of metal binding site of methyl parathion hydrolase ». Phd thesis, 2015. http://hdl.handle.net/1885/149587.
Texte intégralWei, Chieh-Hwa, et 韋建華. « Identification of the Metal Binding Site of Pigeon Liver Malic ». Thesis, 1995. http://ndltd.ncl.edu.tw/handle/45443903656679936060.
Texte intégralLin, Jau-Ji, et 林肇基. « Prediction of Metal-Binding Site Residues Using Support Vector Machine ». Thesis, 2005. http://ndltd.ncl.edu.tw/handle/82371337700374814949.
Texte intégral國立交通大學
生物資訊研究所
93
Correct identification and analysis of the metal-binding site provides useful clues to the modeling and designing of the binding site in proteins for industrial and therapeutic purposes. As the number of the biological data is rapidly accumulated, the use of machine learning approach to do the prediction becomes more reliable now than ever. We have developed a method using support vector machine (SVM) to predict the metal-binding site residues in proteins containing metal ions. The information used to encode the site residues includes sequence profiles and structural features. The results show that the use of buffer zone can effectively improve the true positive rate (TPR) of the prediction. On five-fold cross-validation, we obtain an average prediction accuracy of 97.4% and 46.2% TPR at a 5% false positive rate (FPR). The results indicate that the use of SVM with suitable coding schemes is an effective way to predict the metal-binding sites in proteins.
Shou-YunLu et 盧守筠. « Site-Directed Mutagenesis Studies on the Divalent Metal Ions Binding Site of Rat Lens αB-Crystallin ». Thesis, 2014. http://ndltd.ncl.edu.tw/handle/fwjydk.
Texte intégral國立成功大學
化學系
102
The lens αB-crystallin, playing a major role in maintaining the transparency of the eye lens, possesses chaperone-like function to prevent the lens proteins from aggregation due to foreign stress and/or aging. In nonlenticular cells, it is involved in various neurological diseases, diabetes, and cancer. The role of some metal ions in the αB-crystallin biology has been reported. Theoretical calculations have proposed that the coordination site of human αB-crystallin for binding divalent metal ions were His101, His119, Lys121, His18 and Glu99. In this study, H18G, H119G, and H101G mutant types of rat lens αB-crystalin were cloned and expressed to investigate whether His18, His119 and His101 are the coordination binding sites. And the results suggested that His18, His119 and His101 were the crucial binding sites for Cu (II) and Zn (II) in terms of chaperone-like activity and structure. Copper and zinc at 1 mM concentration significantly increase the chaperone-like activity in wild type αB-crystalin, whereas zinc, copper and magnesium at 1 mM reduced the activity of mutant type significantly. ANS fluorescence measurement showed that there was no linear relationship between chaperone-like activity and surface hydrophobicity, indicating that surface hydrophobicity is not prerequisite for exhibiting chaperone-like activity. Both the Far- and Near-UV CD spectra suggested that the wild type reflected more β-sheet structural characteristics; whereas the mutant type reflected more random coil characteristics and more micro-environmental changes around the tryptophan residues. The results from chaperone-like activity, ANS fluorescence measurement and Far- and Near-UV CD studies indicate that the replacement of His18, His119 and His101 with Glycine resulted in a conformational and minor environmental changes that decrease chaperone-like activity in the presence of divalent ions suggested that His18, His119 and His101 were a crucial binding site for Cu (II) and Zn (II), respectively. All results together suggest that His18, His119 and His101 coordinate each other for the binding site of Cu (II) and Zn (II) in terms of improving the chaperone-like activity and stability of crystallin/metal ion complex, which further confirmed the proposed binding site based on the theoretical calculation.
Gavrilova, Anna Leonidovna. « One-site addition two-metal oxidation reactions of unsymmetrical bimetallic complexes related to dioxygen binding by hemerythrin / ». 2003. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:3108077.
Texte intégralChen, Wei-Nan, et 陳威男. « Evalution of Glutamyl 234 Residue in the Metal Binding Site of Pigeon Liver Malic Enzyme ». Thesis, 2001. http://ndltd.ncl.edu.tw/handle/94295390193799499427.
Texte intégral國防醫學院
生物化學研究所
89
Pigeon liver malic enzyme (EC 1.1.1.40) catalyzed the oxidative decarboxylation of L-malate to CO2 and pyruvate, with concomitant reduction of NDAP+ to NADPH. Glu234 is one of highly conserved amino acid residues among several species. Site-directed mutagenesis method was use to confirm the role of Glu234 in pigeon liver malic enzyme. The preliminary kinetic studies revealed that the apparent KmMn and KmMalate value for E234A were increased by about 300-fold and 15-fold, respectively. From the initial velocity experiment, the KmMn and KdMn of E234A were increased to 450-fold and 620-fold of that of wild type. We proposed that E234A was one of the divalent metal chelate sites of the malic enzyme. In the presences of saturated substrates and cofactor, E234A demonstrated a downward curve instead of a straight line observed in wild type in the kinetic activity assay. The Ki values of NADPH, pyruvate and sodium bicarbonate for E234A were 8 mM, 49 mM and 78 mM, respectively. These values were similar to those for wild type. E234A was more stable than wild type at 30°C. Therefore, the downward curve was not resulted from product inhibition and enzyme stability. Acrylamide quenching studies showed that E234A did not demonstrate a slow conformational change in the presence of Mn2+. The formation of NADP-pyruvate nonproductive adduct was proposed to explain the phenomenon of the downward curve.