scholarly journals Metal Binding Proteins

Encyclopedia ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 261-292
Author(s):  
Eugene A. Permyakov
Keyword(s):  
Metal Ions ◽  
Metal Binding ◽  
Transition Metal Ions ◽  
Short Review ◽  
Sodium Potassium ◽  
Physical Chemical ◽  
Physiological Properties ◽  
Cell Processes ◽  
Living Organisms ◽  
Potassium Magnesium

Metal ions play several major roles in proteins: structural, regulatory, and enzymatic. The binding of some metal ions increase stability of proteins or protein domains. Some metal ions can regulate various cell processes being first, second, or third messengers. Some metal ions, especially transition metal ions, take part in catalysis in many enzymes. From ten to twelve metals are vitally important for activity of living organisms: sodium, potassium, magnesium, calcium, manganese, iron, cobalt, zinc, nickel, vanadium, molybdenum, and tungsten. This short review is devoted to structural, physical, chemical, and physiological properties of proteins, which specifically bind these metal cations.

scholarly journals Studies on Precision and Accuracy In Microdetermination of Transition Metals Using Ternary Complex EAB-CTAB-Metals

2018 ◽  
Vol 34 (4) ◽  
pp. 1930-1936
Author(s):  
Suparna Deshmukh
Keyword(s):  
Metal Ions ◽  
Absorption Spectra ◽  
Ternary Complex ◽  
Cetyl Trimethyl Ammonium Bromide ◽  
Transition Metal Ions ◽  
Ammonium Bromide ◽  
Sodium Potassium ◽  
Ph Values ◽  
Precision And Accuracy ◽  
Cetyl Trimethyl Ammonium

Complexometric and Analytical studies have carried out by forming ternary complex between Eriochrome Azurol B, and Cetyl Trimethyl Ammonium Bromide CTAB; and some transition metal ions mainly Cu2+, Ni2+ and Cd2+. The absorption spectra of Eriochrome Azurol B ,EAB; a triphenylmethane dye, has studied in the presence as well as in the absence of surfactant, Cetyl Trimethyl Ammonium Bromide, CTAB at pH values ranging from pH 1.00 to 12.00. Hypsochromic shift is observed in the absorption spectra in the presence of surfactant pK values i.e. dissociation constant values are found to decreased, in the presence of surfactant is observed. Composition of chelates EAB:CTAB:Metal is found to be 1:1:1, and effect of foreign ions such as chlorides, nitrates; and sulphates of sodium, potassium and ammonium; has been studied in detail. Stability constants of the chelates are determined. Sensitivity and Stability of chelates formedincreases in the presence of surfactant. Various analytical parameters including range of adherence to Beers Law, Molar Extinction Constants, Sandells Sensitivity, were studied for all systems by its interaction with and without CTAB. Precision and Accuracy of the method suggested for microdetermination of metal ions is determined and found out that method is both precise as well as accurate.

METAL BINDING BY HEMOGLOBIN AT DIFFERENT CONDITIONS

2021 ◽  
Author(s):  
Alexey Topunov ◽  
◽  
Olga Kosmachevskaya ◽  
Natalya Novikova ◽  
◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Metal Binding ◽  
Transition Metal Ions ◽  
Endogenous Intoxication

The fact of the formation of additional binding centers of transition metal ions (Zn and Fe) in hemoglobin under conditions simulating endogenous intoxication was revealed. A mechanism for the emergence of such additional centers was proposed.

scholarly journals A microplate screen to estimate metal-binding affinities of metalloproteins

2019 ◽  
Author(s):  
Patrick Diep ◽  
Radhakrishnan Mahadevan ◽  
Alexander F. Yakunin
Keyword(s):  
Metal Ions ◽  
Metal Binding ◽  
Transition Metal Ions ◽  
Titration Calorimetry ◽  
List Type ◽  
Binding Affinities ◽  
Chemical Gradients ◽  
Small Collection ◽  
Protein Libraries ◽  
Clostridium Carboxidivorans

AbstractSolute-binding proteins (SBPs) from ATP-binding cassette (ABC) transporters play crucial roles across all forms of life in transporting compounds against chemical gradients. Some SBPs have evolved to scavenge metal substrates from the environment with nanomolar and micromolar affinities (KD). There exist well established techniques like isothermal titration calorimetry for thoroughly studying these metalloprotein interactions with metal ions, but they are low-throughput. For protein libraries comprised of many metalloprotein homologues and mutants, and for collections of buffer conditions and potential ligands, the throughput of these techniques is paramount. In this study, we describe an improved method termed the microITFQ-LTA and validated it using CjNikZ, a well-characterized nickel-specific SBP (Ni-BP) from Campylobacter jejuni. We then demonstrated how the microITFQ-LTA can be designed to screen through a small collection of buffers and ligands to elucidate the binding profile of a putative Ni-BP from Clostridium carboxidivorans that we call CcSBPII. Through this study, we showed CcSBPII can bind to various metal ions with KD ranged over 3 orders of magnitude. In the presence of L-histidine, CcSBPII could bind to Ni2+ over 2000-fold more tightly, which was 11.6-fold tighter than CjNikZ given the same ligand.Highlightsan improved version of a high-throughput screen (microITFQ-LTA) is described for multiplexed elucidation of metalloprotein binding profilesvalidation was accomplished with the previously characterized CjNikZ; testing was accomplished with an uncharacterized homologue herein named CcSBPIICcSBPII is shown to bind to multiple transition metal ions with a large range of affinities, and potentially overcome mismetallation using a simple histidine metallophore

scholarly journals Iron Complexes of Flavonoids-Antioxidant Capacity and Beyond

2021 ◽  
Vol 22 (2) ◽  
pp. 646
Author(s):  
Zdeněk Kejík ◽  
Robert Kaplánek ◽  
Michal Masařík ◽  
Petr Babula ◽  
Adam Matkowski ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Transition Metal ◽  
Metal Ions ◽  
Biological Effects ◽  
Transition Metal Ions ◽  
Biological Properties ◽  
Biochemical Properties ◽  
Redox Processes ◽  
Living Organisms ◽  
Common Plant

Flavonoids are common plant natural products able to suppress ROS-related damage and alleviate oxidative stress. One of key mechanisms, involved in this phenomenon is chelation of transition metal ions. From a physiological perspective, iron is the most significant transition metal, because of its abundance in living organisms and ubiquitous involvement in redox processes. The chemical, pharmaceutical, and biological properties of flavonoids can be significantly affected by their interaction with transition metal ions, mainly iron. In this review, we explain the interaction of various flavonoid structures with Fe(II) and Fe(III) ions and critically discuss the influence of chelated ions on the flavonoid biochemical properties. In addition, specific biological effects of their iron metallocomplexes, such as the inhibition of iron-containing enzymes, have been included in this review.

HREM Study of electron-induced surface radiation damage in ReO3

1991 ◽  
Vol 49 ◽  
pp. 636-637
Author(s):  
R. Ai ◽  
H.-J. Fan ◽  
L. D. Marks
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Metal Oxides ◽  
Electron Irradiation ◽  
Transition Metal Oxides ◽  
Carbon Film ◽  
Transition Metal Ions ◽  
Surface Radiation ◽  
Valence Transition ◽  
Electron Microscopes

It has been known for a long time that electron irradiation induces damage in maximal valence transition metal oxides such as TiO2, V2O5, and WO3, of which transition metal ions have an empty d-shell. This type of damage is excited by electronic transition and can be explained by the Knoteck-Feibelman mechanism (K-F mechanism). Although the K-F mechanism predicts that no damage should occur in transition metal oxides of which the transition metal ions have a partially filled d-shell, namely submaximal valence transition metal oxides, our recent study on ReO3 shows that submaximal valence transition metal oxides undergo damage during electron irradiation.ReO3 has a nearly cubic structure and contains a single unit in its cell: a = 3.73 Å, and α = 89°34'. TEM specimens were prepared by depositing dry powders onto a holey carbon film supported on a copper grid. Specimens were examined in Hitachi H-9000 and UHV H-9000 electron microscopes both operated at 300 keV accelerating voltage. The electron beam flux was maintained at about 10 A/cm2 during the observation.

Synthesis, Spectral and Antimicrobial Investigation of 2-(Naphthalenel-ylamino)-2- Phenylacetonitrile and 1, 10-Phenanthroline with Five Divalent Transition Metal Ions

2019 ◽  
Vol 10 (01) ◽  
Author(s):  
Mohammed Al-Amery1 ◽  
Ashraf Saad Rasheed ◽  
Dina A. Najeeb
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Transition Metal Ions ◽  
Molar Conductance ◽  
Octahedral Geometry ◽  
Mixed Ligand ◽  
Gram Negative Bacteria ◽  
Magnetic Studies ◽  
Gram Positive Bacteria

Five new mixed ligand metal complexes have been synthesized by the reaction of divalent transition metal ions (Hg, Ni, Zn, Cu and Cd) with 2-(naphthalen-l-ylamino)-2-phenylacetonitrile (L1 ) and 1,10-phenanthroline (L2). The coordination likelihood of the two ligands toward metal ions has been suggested in the light of elemental analysis, UV-Vis spectra, FTIR, 1H-NMR, flam atomic absorption, molar conductance and magnetic studies. Results data suggest that the octahedral geometry for all the prepared complexes. Antibacterial examination of synthesized complexes in vitro was performed against four bacterias. Firstly, Gram-negative bacteria namely, Pseudomonas aerugin and Escherichia. Secondly, Gram-positive bacteria namely, Bacillus subtilis, Staphylococcuaurouss. Results data exhibit that the synthesized complexes exhibited more biological activity than tetracycline pharmaceutical.

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