Interactions between metal ions and living organisms in sea water

Author(s):  
Kenneth Kustin ◽  
Guy C. McLeod
Encyclopedia ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 261-292
Author(s):  
Eugene A. Permyakov

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.


2020 ◽  
Vol 246 ◽  
pp. 119009 ◽  
Author(s):  
Andrea Fiorati ◽  
Giacomo Grassi ◽  
Aurora Graziano ◽  
Giulia Liberatori ◽  
Nadia Pastori ◽  
...  

2014 ◽  
Vol 70 (7) ◽  
pp. 2019-2031 ◽  
Author(s):  
Khaja Faisal Tarique ◽  
Syed Arif Abdul Rehman ◽  
S. Gourinath

The enzyme 3′-phosphoadenosine 5′-phosphatase-1 (PAP phosphatase-1) is a member of the Li+-sensitive Mg2+-dependent phosphatase superfamily, or inositol monophosphatase (IMPase) superfamily, and is an important regulator of the sulfate-activation pathway in all living organisms. Inhibition of this enzyme leads to accumulation of the toxic byproduct 3′-phosphoadenosine 5′-phosphate (PAP), which could be lethal to the organism. Genomic analysis ofEntamoeba histolyticasuggests the presence of two isoforms of PAP phosphatase. The PAP phosphatase-1 isoform of this organism is shown to be active over wide ranges of pH and temperature. Interestingly, this enzyme is inhibited by submillimolar concentrations of Li+, while being insensitive to Na+. Interestingly, the enzyme showed activity towards both PAP and inositol 1,4-bisphosphate and behaved as an inositol polyphosphate 1-phosphatase. Crystal structures of this enzyme in its native form and in complex with adenosine 5′-monophosphate have been determined to 2.1 and 2.6 Å resolution, respectively. The PAP phosphatase-1 structure is divided into two domains, namely α+β and α/β, and the substrate and metal ions bind between them. This is a first structure of any PAP phosphatase to be determined from a human parasitic protozoan. This enzyme appears to function using a mechanism involving three-metal-ion assisted catalysis. Comparison with other structures indicates that the sensitivity to alkali-metal ions may depend on the orientation of a specific catalytic loop.


2021 ◽  
Author(s):  
Ettiyagounder Parameswari ◽  
Tamilselvan Ilakiya ◽  
Veeraswamy Davamani ◽  
Periasami Kalaiselvi ◽  
Selvaraj Paul Sebastian

Metallothionein’s (MTs) are the lower molecular weight (6-7 kDa) proteins that are found to be present in almost all organism types ranging from prokaryotes to eukaryotes species. MT are the metal detecting proteins that can mitigate the effect caused by the excess metal ions. They are also found to be involved in cellular process such as cell growth regulation, ROS (Reactive Oxygen Species) and DNA repair. The protein was termed as Metallothionein due to the unusual higher metal (metallo) and the sulfur (thiol) content. They are further grouped into 3 classes viz., class I, II and III. The Class I and II MTs are polypeptides that were obtained from direct gene products, the class III MTs are from the cysteine-rich non-translational molecules that are termed as phytochelatins. The metal ions are been sequestered through the MTs with Cys rich motifs. All the cysteines are present in the reduced form and are been co-ordinated through the mercaptide bonds. The cysteines present in the MTs are preserved across the species, it is supposed that, cysteines are essential for the function and the MTs are required for the life. Metallothionins structure, conservation in evolution, their ubiquitous nature of occurrence, the genes redundancy and the programmed MTs synthesis in development, regeneration and reproduction of living organisms are some of the weighty arguments in suspecting MTs to also serve others and perhaps the high particular metal-related cellular roles. In this chapter, there is a detailed discussion about Metallothionein its structure, occurrence and function.


2021 ◽  
Vol 15 (2) ◽  
pp. 35-46
Author(s):  
O. M. Сhayka ◽  
◽  
T. B. Peretyatko ◽  
A. A. Halushka ◽  

Introduction. Thermophilic sulfate-reducing bacteria attract attention of scientists as the potential agents of purification of wastewater polluted by sulfur and its compounds, heavy metal ions and organic compounds. These bacteria oxidize different organic substrates using metals with variable valency as electron acceptors and transform them into non-toxic or less toxic forms for living organisms. However, wastewater contains high concentrations of different toxic xenobiotics, particularly, metal ions that have negative influence on living organisms. For this reason, it is important to use resistant strains of microorganisms for the purification of wastewater. The aim of this work was to identify the thermophilic sulfur-reducing bacteria, isolated from “Nadiia” pit spoil heap of Chervonohrad mining region, and to study their properties. Materials and Methods. Thermophilic sulfur-reducing bacteria were isolated from the samples of rock of “Nadiia” pit heap at 50 cm depth. Bacteria were cultivated in TF medium under the anaerobic conditions in anaerostates. Cell biomass was measured turbidimetrically using the photoelectric colorimeter KFK-3 (λ = 340 nm, 3 mm cuvette). Hydrogen sulfide content was measured photoelectrocolorymetrically by the production of methylene blue. Organic acids content was measured by high performance liquid chromatography. Cr(VI), Fe(III), Мn(IV) and NO3– content was measured turbidimetrically. Results. Thermophilic sulfur-reducing bacteria were isolated from the rock of “Nadiia” pit heap of Chervonohrad mining region. They were identified as Moorela thermoacetica based on the morpho-physiological and biochemical properties and on the results of phylogenetic analysis. M. thermoacetica Nadia-3 grow in the synthetic TF medium, have the shape of elongated rods, are gram-positive, endospore-forming. They form light brown colonies. Optimal growth was observed at 50–55 °C, pH 6.5–7. The bacteria utilize glucose, starch, fructose, maltose, lactose, sodium lactate, arabinose, cellulose, maltose, glycerol, fumarate, and ethanol as carbon sources. The highest sulfidogenic activity of M. thermoacetica Nadia-3 was found in media with glycerol, lactose, and glucose. M. thermoacetica Nadia-3 reduce SO42-, S2O32-, Fe(III), NO3–, Cr(VI) compounds besides elemental sulfur. They accumulate biomass at K2Cr2O7 concentrations of 0.1–1 mM. Sulfur reduction is not the main way of energy accumulation. Conclusions. Thermophilic chromium-resistant sulfur-reducing bacteria M. thermoacetica Nadia-3, that produce hydrogen sulfide during the oxidation of different organic compounds, were isolated from the rock of “Nadiia” pit heap. They reduce Fe(III), Cr(VI), NO3–, SO42-, S2O32-, besides elemental sulfur.


2020 ◽  
Author(s):  
AMIT NAIN

In this study, effect of noble metal ions (Au, Ag and Cu) on the synthesis of metal nanoclusters (MNCs) have been investigated. Through heating at 70ºC, TSA/BSA–Au, –Ag and –Cu NCs were separately prepared from Au3+, Ag+ and Cu2+ respectively in the presence of bovine serum albumin (BSA) and thiosalicylic acid (TSA). They exhibit photoluminescence (PL) at 700, 624 and 430 nm, with an average life times of 1500, 100 and 11.71 ns, respectively, when excited at 350 nm. X–ray photoelectron spectroscopy (XPS) data support the presence of metal core (M0) and metal–thiolate shell (Mn–SRm) in each of the TSA/BSA–Metal nanoclusters (MNCs). Spectroscopic measurements reveal the formation of Au32–SR, Ag9–SR and (Cu4–Cu13)–SR species in the TSA/BSA–Au, –Ag and –Cu NCs respectively. Through PL quenching of the TSA/BSA–Au, –Ag and –Cu NCs, they have been used separately for quantitation of Hg2+, As3+ and Cr6+ , with linear ranges of 1400, 418, and 40400 nM and limits of detection (LODs) of 0.25, 2.34 and 3.54 nM, respectively. The PL quenching is mainly due to aggregation of the MNCs via metal–metal or metal–thiol interaction. The stable TSA/BSA–Au, –Ag and –Cu NCs have been employed separately for the determination of the concentrations of Hg2+, As3+ and Cr6+ ions in the spiked sea water samples, showing advantages of simplicity, rapidity, high selectivity, and sensitivity.


2020 ◽  
Author(s):  
Dhanya Nilesh Poojary ◽  
Malika Ahuja

Abstract Natural preservation techniques of food are associated with various naturally producing antibacterial property of various biologically active compounds obtained from plants, spices, animals and microbes. Garlic (Allium sativum) is the prominent biologically active source possessing greater antimicrobial property. Expansion of shelf life, declines the spoilage mechanism by the use of garlic. Garlic exhibits not only preservative properties but also has a biological activity viz. antibacterial, antimicrobial, anti-inflammatory, antiprotozoal, anti-helminthic, antifungal, wound healing, antitumor, and insecticidal. Allyl alcohol, allicin is an active biological compound present in garlic. Fish is highly beneficial and wholesome food as it contains high quantity of proteins and minerals as compared to other meat sources. Fresh fishes easily deteriorate due to high moisture and nutrient content. Spoilage of food begins as soon as fish dies. Hence, many preservation techniques are used to escalate the shelf life of fish. Enzymatic action of bacteria do not cause any variation in the metabolic activities of living organisms due to its existing immunity against it. As soon as the fish perishes, the enzymes associated with the catalytic activities in flesh and guts are now responsible for the autolytic reaction. Decomposition can be identified by its color change, foul odor and its texture. Various physiological analysis of these fishes were done with respect to their weight, color, texture, softness, and appearance. Further on microbial analysis were performed to identify and characterize the fish isolate, followed by its biochemical test. Various parameters were evaluated with respect to quality and shelf life of fishes with and without garlic as the natural preservative.


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