scholarly journals Insights into the antibacterial mechanism of action of chelating agents by selective deprivation of iron, manganese and zinc

2021 ◽  
Author(s):  
Joy R. Paterson ◽  
Marikka S. Beecroft ◽  
Raminder S. Mulla ◽  
Deenah Osman ◽  
Nancy L. Reeder ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Growth Inhibition ◽  
Metal Ions ◽  
Mechanism Of Action ◽  
Bacterial Growth ◽  
Metal Ion ◽  
Chelating Agents ◽  
Antibacterial Mechanism ◽  
Zinc Levels ◽  
Iron Manganese

Bacterial growth and proliferation can be restricted by limiting the availability of metal ions in their environment. Humans sequester iron, manganese and zinc to help prevent infection by pathogens, a system termed nutritional immunity. Commercially-used chelants have high binding affinities with a variety of metal ions, which may lead to antibacterial properties that mimic these innate immune processes. However, the modes of action of many of these chelating agents in bacterial growth inhibition and their selectivity in metal deprivation in cellulo remain ill-defined. We address this shortcoming by examining the effect of eleven chelators on Escherichia coli growth and their impact on the cellular concentration of five metals. Four distinct effects were uncovered: i) no apparent alteration in metal composition, ii) depletion of manganese alongside reductions in iron and zinc levels, iii) reduced zinc levels with a modest reduction in manganese, and iv) reduced iron levels coupled with elevated manganese. These effects do not correlate with the absolute known chelant metal ion affinities in solution, however, for at least five chelators for which key data are available, they can be explained by differences in the relative affinity of chelants for each metal ion. The results reveal significant insights into the mechanism of growth inhibition by chelants, highlighting their potential as antibacterials and as tools to probe how bacteria tolerate selective metal deprivation. IMPORTANCE Chelating agents are widely used in industry and consumer goods to control metal availability, with bacterial growth restriction as a secondary benefit for preservation. However, the antibacterial mechanism of action of chelants is largely unknown, particularly with respect to the impact on cellular metal concentrations. The work presented here uncovers distinct metal starvation effects imposed by different chelants on the model Gram-negative bacterium Escherichia coli . The chelators were studied both individually and in pairs with the majority producing synergistic effects in combinations that maximise antibacterial hostility. The judicious selection of chelants based on contrasting cellular effects should enable reductions in the quantities of chelant required in numerous commercial products and presents opportunities to replace problematic chemistries with biodegradable alternatives.

scholarly journals Investigation of the nature of the two metal-binding sites in 5-aminolaevulinic acid dehydratase from Escherichia coli

1994 ◽  
Vol 300 (2) ◽  
pp. 373-381 ◽  
Author(s):  
P Spencer ◽  
P M Jordan
Keyword(s):  
Escherichia Coli ◽  
Metal Ions ◽  
Metal Binding ◽  
Binding Sites ◽  
Metal Ion ◽  
Protein Fluorescence ◽  
Metal Binding Sites ◽  
Aminolaevulinic Acid ◽  
Acid Dehydratase ◽  
Aminolaevulinic Acid Dehydratase

Two distinct metal-binding sites, termed alpha and beta, have been characterized in 5-aminolaevulinic acid dehydratase from Escherichia coli. The alpha-site binds a Zn2+ ion that is essential for catalytic activity. This site can also utilize other metal ions able to function as a Lewis acid in the reaction mechanism, such as Mg2+ or Co2+. The beta-site is exclusively a transition-metal-ion-binding site thought to be involved in protein conformation, although a metal bound at this site only appears to be essential for activity if Mg2+ is to be bound at the alpha-site. The alpha- and beta-sites may be distinguished from one another by their different abilities to bind divalent-metal ions at different pH values. The occupancy of the beta-site with Zn2+ results in a decrease of protein fluorescence at pH 6. Occupancy of the alpha- and beta-sites with Co2+ results in u.v.-visible spectral changes. Spectroscopic studies with Co2+ have tentatively identified three cysteine residues at the beta-site and one at the alpha-site. Reaction with N-ethyl[14C]maleimide preferentially labels cysteine-130 at the alpha-site when Co2+ occupies the beta-site.

scholarly journals Potassium Permanganate-Catalyzed Alpha-Pinene Oxidation: Formation of Coordination Compound with Zinc(II) and Copper(II), and Growth Inhibition Activity on Staphylococcus aureus and Escherichia coli

2018 ◽  
Vol 16 (1) ◽  
pp. 59 ◽  
Author(s):  
Masruri Masruri ◽  
Rekfa Wika Amini ◽  
Mohammad Farid Rahman
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Growth Inhibition ◽  
Potassium Permanganate ◽  
Bacterial Growth ◽  
Complex Compound ◽  
Oxidation Product ◽  
Inhibition Activity ◽  
Alpha Pinene ◽  
Growth Inhibition Activity

Catalytic oxidation of alpha-pinene was investigated using potassium permanganate as an oxidant. The reaction consumed catalyst following stoichiometric amount instead of the catalytic one. The keto-carboxylate compound 2 was afforded as the oxidation product. Further study of its complex compound with copper(II) and zinc(II) was also reported including their activity for inhibiting the growth of Staphylococcus aureus and Escherichia coli. In overall, the complex compound shows important result by inhibiting the bacterial growth.

The role of metal ions in the virulence and viability of bacterial pathogens

2019 ◽  
Vol 47 (1) ◽  
pp. 77-87 ◽  
Author(s):  
Stephanie L. Begg
Keyword(s):  
Metal Ions ◽  
Metal Ion ◽  
Molecular Mechanisms ◽  
Bacterial Pathogens ◽  
Ion Homeostasis ◽  
Transition Metal Ions ◽  
Metal Ion Homeostasis ◽  
And Function ◽  
Iron Manganese

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.

scholarly journals Growth inhibition ofMicrocystic aeruginosaby metal–organic frameworks: effect of variety, metal ion and organic ligand

RSC Advances ◽  
2018 ◽  
Vol 8 (61) ◽  
pp. 35314-35326 ◽  
Author(s):  
Gongduan Fan ◽  
Liang Hong ◽  
Xiaomei Zheng ◽  
Jinjin Zhou ◽  
Jiajun Zhan ◽  
...  
Keyword(s):  
Growth Inhibition ◽  
Metal Ions ◽  
Metal Ion ◽  
Metal Organic Frameworks ◽  
Organic Ligand ◽  
Organic Ligands ◽  
Metal Organic

MOFs have been applied in the inactivation ofMicrocystic aeruginosa. The algal suppression by MOFs depends on the presence of different metal ions and organic ligands.

Removal of Iron, Manganese and Boron from Industrial Effluent Water Using Carbon Nanofibers

2015 ◽  
Vol 1109 ◽  
pp. 158-162
Author(s):  
Norli Abdullah ◽  
Imran Syakir Mohamad ◽  
Sharifah Bee Abd Hamid
Keyword(s):  
Activated Carbon ◽  
Metal Ions ◽  
Carbon Nanofibers ◽  
Metal Ion ◽  
Industrial Effluent ◽  
Carbon Surface ◽  
Effluent Water ◽  
Manganese Ion ◽  
Boron Ions ◽  
Iron Manganese

Carbon based materials are widely used as an absorbent to study the adsorption capacity of several metal ions (Fe, Mn, B) from industrial effluent water. In this project, three types of carbon materials were selected; (1) activated carbon (AC), (2) Carbon nanofibers supported on activated carbon (CNF-AC) and (3) commercial carbon nanofibers (CNF-C). CNF-AC is physically in the form of nanofibers which directly attached onto activated carbon surface, meanwhile CNF-C is un-attached/loose nanofibers. It was found that pH of effluent water and the type of adsorbent play important roles for adsorption of metal ions. The higher adsorption of iron ions was observed when the pH of effluent water adjusted to pH 6 with an adsorbent capacity order is CNF-AC>CNF-C>AC. Furthermore, the adsorption order for manganese ion represent as AC>CNF-AC>CNF-C. Different behavior was observed for boron ions which show higher adsorption at pH 4 with the affinities order is CNF-AC>CNF-C>AC. The results show that CNF-AC has a potential to be used as effective adsorbent for removal of metal ion from industrial effluent water for environment protection.

scholarly journals Mechanistic and In silico Characterization of Metal ion Requirements of Escherichia coli Zinc Phosphodiesterase Activity

2020 ◽  
Vol 5 (1) ◽  
pp. 56-65
Author(s):  
Adedoyin Igunnu ◽  
Micheal F. Dada ◽  
Tamonokorite AbelJack-Soala ◽  
Ireoluwa Y. Joel ◽  
Oluwafunmibi O. Lanre-Ogun ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Metal Ions ◽  
Binding Affinity ◽  
Metal Ion ◽  
Phosphoryl Transfer ◽  
Phosphodiesterase Activity ◽  
Divalent Metal Ions ◽  
Nitrophenyl Phosphate ◽  
In Silico Characterization ◽  
Affinity Score

AbstractZinc phosphodiesterase (ZiPD) participates in the maturation of tRNA precursors. The roles of metal ions in promoting phosphoryl transfer reaction on zinc phosphodiesterase (ZiPD) activity have not been fully characterized. Therefore, this study investigated the effects of some metal ions on phosphodiesterase activity of Escherichia coli ZiPD as well as the binding site and binding affinity of the metal ions. ZiPD activity was measured by monitoring the rate of hydrolysis of bis-para-nitrophenyl phosphate (bis-pNPP) in the presence of some selected divalent metal ions (Mn2+, Co2+, Mg2+ and Zn2+). The results obtained revealed that Mn2+ at 1 mM activated ZiPD activity by 4-fold with binding affinity score of 1.795. Co2+ at 0.5 mM activated ZiPD activity by 2-fold with binding affinity score of 1.773. Mg2+ at 0.5 mM enhanced the binding affinity of ZiPD for bis-pNPP but did not increase the turnover rate of ZiPD. Zn2+ at 1.5 mM activated ZiPD activity by 2-fold via increased affinity of ZiPD for bis-pNPP. In conclusion, the findings from this study showed that Mn2+ and Zn2+ are the most effective stimulatory ions of ZiPD for bis-pNPP while Zn2+ exerted the highest binding affinity of ZiPD for bis-pNPP.

scholarly journals Homocysteine editing and growth inhibition in Escherichia coli

Microbiology ◽  
2009 ◽  
Vol 155 (6) ◽  
pp. 1858-1865 ◽  
Author(s):  
Marta Sikora ◽  
Hieronim Jakubowski
Keyword(s):  
Escherichia Coli ◽  
Energy Dissipation ◽  
Growth Inhibition ◽  
Bacterial Growth ◽  
Growth Rates ◽  
Isoleucine Leucine ◽  
Trna Synthetases ◽  
E Coli

In Escherichia coli homocysteine (Hcy) is metabolically converted to the thioester Hcy-thiolactone in ATP-consuming reactions catalysed by methionyl-, isoleucyl- and leucyl-tRNA synthetases. Here we show that growth inhibition caused by supplementation of E. coli cultures with Hcy is accompanied by greatly increased accumulation of Hcy-thiolactone. Energy dissipation for Hcy editing increases 100-fold in the presence of exogenous Hcy and reaches one mole of ATP unproductively dissipated for Hcy-thiolactone synthesis per each mole of ATP that is consumed for methionine activation. Inhibiting Hcy-thiolactone synthesis with isoleucine, leucine or methionine accelerates bacterial growth in Hcy-supplemented cultures. Growth rates in Hcy-inhibited cultures are inversely related to the accumulation of Hcy-thiolactone. We also show that the levels of protein N-linked Hcy modestly increase in E. coli cells in Hcy-supplemented cultures. The results suggest that Hcy editing restrains bacterial growth.

scholarly journals Crucial role of ppGpp in the resilience of Escherichia coli to growth disruption

2020 ◽  
Author(s):  
Clément Patacq ◽  
Nicolas Chaudet ◽  
Fabien Letisse
Keyword(s):  
Escherichia Coli ◽  
Growth Inhibition ◽  
Bacterial Growth ◽  
Crucial Role ◽  
Stringent Response ◽  
E Coli ◽  
Changing Environments ◽  
Growth Recovery ◽  
Growth Disruption

ABSTRACTBacteria grow in constantly changing environments that can suddenly become completely deleted in essential nutrients. The stringent response, a rewiring of the cellular metabolism mediated by the alarmone (p)ppGpp, plays a crucial role in adjusting bacterial growth to the severity of the nutritional insult. The ability of (p)ppGpp to trigger a slowdown of cell growth or induce bacterial dormancy has been widely investigated. However, little is known about the role of (p)ppGpp in promoting growth recovery after severe growth inhibition. In this study, we performed a time-resolved analysis of (p)ppGpp metabolism in Escherichia coli as it recovered from a sudden slowdown in growth. Results show that E. coli recovers by itself from the growth disruption provoked by the addition of serine hydroxamate, the serine analogue that we used to induce the stringent response. Growth inhibition was accompanied by a severe disturbance of metabolic activity and more surprisingly, by a transient overflow of valine and alanine. Our data also show that ppGpp is crucial for growth recovery since in the absence of ppGpp, E. coli’s growth recovery was slower. In contrast, an increased concentration of pppGpp was found to have no significant effect on growth recovery. Interestingly, the observed decrease in intracellular ppGpp levels in the recovery phase correlated with bacterial growth and the main effect involved was identified as growth dilution rather than active degradative process. This report thus significantly expands our knowledge of (p)ppGpp metabolism in E. coli physiology.IMPORTANCEThe capacity of microbes to resist and overcome environmental insults, know as resilience, allows them to survive in changing environments but also to resist antibiotic and biocide treatments, immune system responses. Although the role of the stringent response in bacterial resilience to nutritional insults has been well studied, little is known about its importance in the ability of the bacteria to not just resist but also recover from these disturbances. To address this important question, we investigated growth disruption resilience in the model bacterium Escherichia coli and its dependency on the stringent response alarmone (p)ppGpp by quantifying ppGpp and pppGpp levels as growth was disrupted and then recovered. Our findings may thus contribute to understanding how ppGpp improves E. coli’s resilience to nutritional stress and other environmental insults.

Growth Inhibition of Listeria monocytogenes, Salmonella enterica, and Escherichia coli O157:H7 by d-Tryptophan as an Incompatible Solute

2015 ◽  
Vol 78 (4) ◽  
pp. 819-824 ◽  
Author(s):  
SHIGENOBU KOSEKI ◽  
NOBUTAKA NAKAMURA ◽  
TAKEO SHIINA
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Listeria Monocytogenes ◽  
Osmotic Stress ◽  
Growth Inhibition ◽  
Bacterial Growth ◽  
Salmonella Enterica ◽  
Compatible Solutes ◽  
Escherichia Coli O157 ◽  
Bacterial Physiology

Under osmotic stress, bacterial cells uptake compatible solutes such as glycine-betaine to maintain homeostasis. It is unknown whether incompatible solutes exist that are similar in structure to compatible solutes but have adverse physiological effects on bacterial physiology. The objective of this study was to evaluate solute incompatibility of various amino acids against bacterial growth. Bacterial growth was evaluated by changes in optical density at 595 nm in peptone-yeast-glucose (PYG) broth. Twenty-three amino acids with l and/or d isomers were examined for the effect of bacterial growth inhibition. Among the various amino acids examined, d-tryptophan (~40 mM) in PYG broth supplemented with 0 to 4% (wt/vol) salt inhibited the growth of Listeria monocytogenes, Salmonella enterica, and Escherichia coli O157:H7 at 25°C. d-Tryptophan (30 to 40 mM) completely inhibited the growth of E. coli O157:H7 and Salmonella in the presence of >3% salt, but the growth of L. monocytogenes was not completely inhibited under the same conditions. Low concentrations of salt (0 to 2% NaCl) with d-tryptophan did not significantly inhibit the growth of all bacteria except L. monocytogenes, which was relatively inhibited at 0% NaCl. The effect of d-tryptophan differed depending on the bacterial species, illustrating the difference between gram-positive and gram-negative bacteria. These results indicate that the uptake of d-tryptophan as a compatible solute during osmotic stress may inhibit bacterial growth. The antibacterial effect of d-tryptophan found in this study suggests that d-tryptophan could be used as a novel preservative for controlling bacterial growth in foods.

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