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 ◽  
...  

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.

2021 ◽  
Author(s):  
◽  
Margaret Lockhart Dickson

<p>The importance of trace metal ions in biological processes has been known for some time, but the role of chelating molecules in the human body is a comparatively new and interesting field of research Schubert, j., 1966, Scientific American, 214, no. 5, 40. Among the important complexes occuring in the body are haemoglobin, containing iron, and vitamin B-12, containing cobalt, both essential to human health. Other well-known naturally occuring complexes include cytochrome oxidase, containing both iron and copper, and chlorophyll, containing magnesium. The transition metal ions of the First Transition Series are well-known for their ability to form complexes with suitable ligands, and in particular with chelate ligands which can seize the metal ion like a claw (chele means claw in Greek). Many of these complexes have been characterized experimentally, and their properties interpreted by theoretical calculations. However, the complexes arising from biological systems are much more difficult to study, partly because of their greater size and special properties.</p>


2021 ◽  
Author(s):  
◽  
Margaret Lockhart Dickson

<p>The importance of trace metal ions in biological processes has been known for some time, but the role of chelating molecules in the human body is a comparatively new and interesting field of research Schubert, j., 1966, Scientific American, 214, no. 5, 40. Among the important complexes occuring in the body are haemoglobin, containing iron, and vitamin B-12, containing cobalt, both essential to human health. Other well-known naturally occuring complexes include cytochrome oxidase, containing both iron and copper, and chlorophyll, containing magnesium. The transition metal ions of the First Transition Series are well-known for their ability to form complexes with suitable ligands, and in particular with chelate ligands which can seize the metal ion like a claw (chele means claw in Greek). Many of these complexes have been characterized experimentally, and their properties interpreted by theoretical calculations. However, the complexes arising from biological systems are much more difficult to study, partly because of their greater size and special properties.</p>


2019 ◽  
Vol 47 (1) ◽  
pp. 77-87 ◽  
Author(s):  
Stephanie L. Begg

AbstractMetal ions fulfil a plethora of essential roles within bacterial pathogens. In addition to acting as necessary cofactors for cellular proteins, making them indispensable for both protein structure and function, they also fulfil roles in signalling and regulation of virulence. Consequently, the maintenance of cellular metal ion homeostasis is crucial for bacterial viability and pathogenicity. It is therefore unsurprising that components of the immune response target and exploit both the essentiality of metal ions and their potential toxicity toward invading bacteria. This review provides a brief overview of the transition metal ions iron, manganese, copper and zinc during infection. These essential metal ions are discussed in the context of host modulation of bioavailability, bacterial acquisition and efflux, metal-regulated virulence factor expression and the molecular mechanisms that contribute to loss of viability and/or virulence during host-imposed metal stress.


Author(s):  
Mazen Hamed

Ferric uptake regulation protein is a repressor protein which binds an AT rich region of DNA (the iron box). Fur binds as a dimer in a helix turn helix mode and it is activated by iron(II) and other transition metal ions at elevated concentrations. Each transition metal ion induces certain conformational changes to aid the Fur binding, both the N-terminal and C-terminal domains take part in binding to DNA in addition to His 88 and His 86. The process is discussed in view of experimental reports. Fe(II), Mn(II) and Co(II) activate Fur to bind DNA but Zinc plays a structural role and does not activate Fur to bind DNA.


Author(s):  
Mazen Hamed ◽  
Salih Jabour

Ferric uptake regulation protein is a repressor protein which binds an AT rich region of DNA (the iron box). Fur binds as a dimer in a helix turn helix mode and it is activated by iron(II) and other transition metal ions at elevated concentrations. Each transition metal ion induces certain conformational changes to aid the Fur binding, both the N-terminal and C-terminal domains take part in binding to DNA in addition to His 88 and His 86. The process is discussed in view of experimental reports. Fe(II), Mn(II) and Co(II) activate Fur to bind DNA but Zinc plays a structural role and does not activate Fur to bind DNA.


Author(s):  
Mazen Hamed ◽  
Salih Jabour

Ferric uptake regulation protein is a repressor protein which binds an AT rich region of DNA (the iron box). Fur binds as a dimer in a helix turn helix mode and it is activated by iron(II) and other transition metal ions at elevated concentrations. Each transition metal ion induces certain conformational changes to aid the Fur binding, both the N-terminal and C-terminal domains take part in binding to DNA in addition to His 88 and His 86. The process is discussed in view of experimental reports. Fe(II), Mn(II) and Co(II) activate Fur to bind DNA but Zinc plays a structural role and does not activate Fur to bind DNA.


Author(s):  
Mazen Hamed ◽  
Salih Jabour

Ferric uptake regulation protein is a repressor protein which binds an AT rich region of DNA (the iron box). Fur binds as a dimer in a helix turn helix mode and it is activated by iron(II) and other divalent transition metal ions at elevated concentrations in a process to regulate the ion uptake. Each transition metal ion induces certain conformational changes to aid the Fur binding, both the N-terminal and C-terminal domains take part in binding to DNA in addition to His 88 and His 86 residues. The process is discussed in view of experimental reports. Fe(II), Mn(II) and Co(II) activate Fur to bind DNA experimentally but Zinc plays a structural role and does not activate Fur to bind DNA.


2021 ◽  
Vol 22 (12) ◽  
pp. 6458
Author(s):  
Aleksandra Pieniężna ◽  
Weronika Witak ◽  
Aneta Szymańska ◽  
Justyna Brasuń

In this paper, we present studies on the influence of the disulfide bridge on the copper (II) ions’ binding abilities by the cyclic His4-peptide. The studied ligand HKHPHRHC-S-S-C consists of nine amino acids. The cyclic structure was obtained through a disulfide bridge between two cysteinyl groups. Moreover, this peptide is characterized by the presence of four His residues in the sequence, which makes it an interesting ligand for transition metal ions. The potentiometric and spectroscopic (UV-Vis spectroscopy and circular dichroism spectroscopy (CD)) studies were carried out in various molar ligand to metal ratios: 2:1, 1:1, and 1:2, in the pH range of 2.5–11 at 25 °C. The results showed that the cyclic His4-peptide promotes dinuclear complexes in each of these systems and forms the final dinuclear species with the {NIm, 3N-amide}{NIm, 3N-amide} coordination mode. The obtained data shows that cyclization by the formation of the disulfide bond has an impact on the peptide chain flexibility and appearance of additional potential donors for metal ions and influences the copper (II) ions’ coordination.


2014 ◽  
Vol 76 ◽  
pp. S124
Author(s):  
Juan Du ◽  
Brett A Wagner ◽  
Garry R Buettner ◽  
Joseph J Cullen

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