Probing the Role of Metal Ions in RNA Catalysis:  Kinetic and Thermodynamic Characterization of a Metal Ion Interaction with the 2‘-Moiety of the Guanosine Nucleophile in theTetrahymenaGroup I Ribozyme†

Biochemistry ◽  
1999 ◽  
Vol 38 (34) ◽  
pp. 10958-10975 ◽  
Author(s):  
Shu-ou Shan ◽  
Daniel Herschlag
Keyword(s):  
Metal Ions ◽  
Metal Ion ◽  
Rna Catalysis ◽  
Thermodynamic Characterization

Structural and Thermodynamic Characterization of theEscherichia coliRelBE Toxin−Antitoxin System:  Indication for a Functional Role of Differential Stability†

Biochemistry ◽  
2007 ◽  
Vol 46 (43) ◽  
pp. 12152-12163 ◽  
Author(s):  
Izhack Cherny ◽  
Martin Overgaard ◽  
Jonas Borch ◽  
Yaron Bram ◽  
Kenn Gerdes ◽  
...  
Keyword(s):  
Functional Role ◽  
Thermodynamic Characterization ◽  
Differential Stability

Why do zeolites induce an unprecedented electronic state on exchanged metal ions?

2017 ◽  
Vol 19 (36) ◽  
pp. 25105-25114 ◽  
Author(s):  
Akira Oda ◽  
Takahiro Ohkubo ◽  
Takashi Yumura ◽  
Hisayoshi Kobayashi ◽  
Yasushige Kuroda
Keyword(s):  
Metal Ions ◽  
Electronic State ◽  
Base Metal ◽  
Metal Ion ◽  
High Efficiency ◽  
Lewis Base ◽  
Mfi Zeolite ◽  
Adsorption Processes ◽  
Exact Position

Understanding the exact position and the detailed role of the Al array in zeolites is essential for elucidating the origin of unique properties and for designing zeolite materials with high efficiency in catalytic and adsorption processes. In this work, we advanced pivotal roles of Lewis base–metal ion bifunctionality caused by Al atoms arrayed circumferentially in the MFI-zeolite pores.

scholarly journals The Role of Metals in the Reaction Catalyzed by Metal-Ion-Independent Bacillary RNase

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Yulia Sokurenko ◽  
Vera Ulyanova ◽  
Pavel Zelenikhin ◽  
Alexey Kolpakov ◽  
Dmitriy Blokhin ◽  
...  
Keyword(s):  
Metal Ions ◽  
Rna Structure ◽  
Metal Ion ◽  
Extracellular Enzymes ◽  
Bacillus Pumilus ◽  
Transition Metal Ions ◽  
The Body ◽  
Intestinal Microbiome ◽  
Phosphodiester Bond

Extracellular enzymes of intestinal microbiota are the key agents that affect functional activity of the body as they directly interact with epithelial and immune cells. Several species of theBacillusgenus, likeBacillus pumilus, a common producer of extracellular RNase binase, can populate the intestinal microbiome as a colonizing organism. Without involving metal ions as cofactors, binase depolymerizes RNA by cleaving the 3′,5′-phosphodiester bond and generates 2′,3′-cyclic guanosine phosphates in the first stage of a catalytic reaction. Maintained in the reaction mixture for more than one hour, such messengers can affect the human intestinal microflora and the human body. In the present study, we found that the rate of 2′,3′-cGMP was growing in the presence of transition metals that stabilized the RNA structure. At the same time, transition metal ions only marginally reduced the amount of 2′,3′-cGMP, blocking binase recognition sites of guanine at N7 of nucleophilic purine bases.

scholarly journals Elucidating the role of metal ions in carbonic anhydrase catalysis

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Jin Kyun Kim ◽  
Cheol Lee ◽  
Seon Woo Lim ◽  
Aniruddha Adhikari ◽  
Jacob T. Andring ◽  
...  
Keyword(s):  
Carbonic Anhydrase ◽  
Metal Ions ◽  
Metal Ion ◽  
Catalytic Mechanism ◽  
Chemical Properties ◽  
Water Network ◽  
Native Metal ◽  
Trigonal Bipyramidal ◽  
Electrostatic Effect

Abstract Why metalloenzymes often show dramatic changes in their catalytic activity when subjected to chemically similar but non-native metal substitutions is a long-standing puzzle. Here, we report on the catalytic roles of metal ions in a model metalloenzyme system, human carbonic anhydrase II (CA II). Through a comparative study on the intermediate states of the zinc-bound native CA II and non-native metal-substituted CA IIs, we demonstrate that the characteristic metal ion coordination geometries (tetrahedral for Zn2+, tetrahedral to octahedral conversion for Co2+, octahedral for Ni2+, and trigonal bipyramidal for Cu2+) directly modulate the catalytic efficacy. In addition, we reveal that the metal ions have a long-range (~10 Å) electrostatic effect on restructuring water network in the active site. Our study provides evidence that the metal ions in metalloenzymes have a crucial impact on the catalytic mechanism beyond their primary chemical properties.

Adsorption of Cu2+ Metal Ions on Dithizone-Immobilized Natural Bentonite

2020 ◽  
Vol 840 ◽  
pp. 64-70
Author(s):  
Dian Mira Fadela ◽  
Mudasir Mudasir ◽  
Adhitasari Suratman
Keyword(s):  
Adsorption Isotherm ◽  
Complex Formation ◽  
Metal Ions ◽  
Electrostatic Interaction ◽  
Metal Ion ◽  
Synthesis And Characterization ◽  
Optimum Conditions ◽  
Initial Concentration ◽  
Activated Bentonite

The research of adsorption of Cu2+ metal ion on dithizone-immobilized natural bentonite (DNB) had been carried out. The experiment was begun by the activation of natural bentonite with HCl 4 M and dithizone-immobilized on activated bentonite surface. This study included synthesis and characterization of dithizone-immobilized bentonite and its application in adsorption of Cu2+ metal ions. The type of interaction occurred in the adsorption was tested by sequential desorption. The result showed that dithizone successfully immobilized on activated natural bentonite (ANB). The optimum conditions for Cu2+ metal ions adsorption using dithizone-immobilized natural bentonite are at pH 5; 0.1 g mass of adsorbent, with interaction time 60 min, and the initial concentration of ion at 80 ppm. Kinetics and adsorption isotherm studies suggest that the capacity, of the dithizone-immobilized natural bentonite in adsorbing Cu2+ metal ion is significantly improved compared to activated natural bentonite. The adsorption of Cu2+ metal ions by activated natural bentonite was through several interactions dominated by electrostatic interaction (82%). Otherwise, the interaction of dithizone-immobilized natural bentonite with Cu2+ metal ions in the sequence were dominated by the mechanism of complex formation of (75%). The result shows that the immobilization of dithizone changes the type of electrostatic interaction into complex formation.

scholarly journals On the unsuspected role of multivalent metal ions on the charge storage of a metal oxide electrode in mild aqueous electrolytes

2019 ◽  
Vol 10 (38) ◽  
pp. 8752-8763 ◽  
Author(s):  
Yee-Seul Kim ◽  
Kenneth D. Harris ◽  
Benoît Limoges ◽  
Véronique Balland
Keyword(s):  
Metal Oxide ◽  
Metal Ions ◽  
Metal Ion ◽  
Charge Storage ◽  
Aqueous Electrolytes ◽  
Electron Charge ◽  
Oxide Electrode ◽  
Metal Ion Complexes ◽  
Multivalent Metal

The hidden role of hexaaquo metal ion complexes in the proton-coupled electron charge storage at a metal oxide electrode.

Towards the role of metal ions in the structural variability of proteins: CdII speciation of a metal ion binding loop motif

Metallomics ◽  
2011 ◽  
Vol 3 (12) ◽  
pp. 1331 ◽  
Author(s):  
Attila Jancsó ◽  
Dániel Szunyogh ◽  
Flemming H. Larsen ◽  
Peter W. Thulstrup ◽  
Niels Johan Christensen ◽  
...  
Keyword(s):  
Metal Ions ◽  
Metal Ion ◽  
Ion Binding ◽  
Metal Ion Binding ◽  
Structural Variability ◽  
Binding Loop
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