Chemical Speciation of Environmentally Significant Metals with Inorganic Ligands. Part 2. The Cu2+—OH‐, Cl‐, CO32‐, SO42‐, and PO43‐ Systems (IUPAC Technical Report)

Powell, Kipton J.; Brown, Paul L.; Byrne, Robert H.; Gajda, Tamás; Hefter, Glenn; Sjöberg, Staffan; Wanner, Hans

doi:10.1002/chin.200740221

Cited by 2 publications

(2 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Figure 7) and, presumably, other microbes. Hst5 outcompetes background competing ligands that may also bind Cu, such as phosphate (log K Cu ~ 3.3 61 ) and amino acids. In addition, Hst5 likely outcompetes transporters that catalyse non-specific Cu(II) uptake into GAS.…”

Section: Discussionmentioning

confidence: 99%

The role of metal binding in the function of the human salivary antimicrobial peptide histatin-5

Stewart

Hong

Holmes

et al. 2022

Preprint

View full text Add to dashboard Cite

The family of human salivary histidine-rich peptides known as histatins bind zinc (Zn) and copper (Cu), but whether they contribute to nutritional immunity by influencing Zn and/or Cu availability has not been examined. We hypothesised that histatin-5 (Hst5) limits Zn availability (and promotes bacterial Zn starvation) and/or raises Cu availability (and promotes bacterial Cu poisoning). To test this hypothesis, Group A Streptococcus (GAS), which colonises the human oropharynx, was used as a model bacterium. Contrary to our hypothesis, Hst5 did not strongly influence Zn availability. This peptide did not induce expression of Zn uptake genes in GAS, nor did it suppress growth of an ΔadcAI mutant strain that is impaired in Zn uptake. Equilibrium competition measurements confirmed that Hst5 binds Zn weakly and does not compete with the high-affinity Zn uptake protein AdcAI for binding Zn. By contrast, Hst5 bound Cu with a high affinity and strongly influenced Cu availability. However, contrary to our hypothesis, Hst5 did not promote Cu toxicity. Instead, this peptide suppressed expression of Cu-inducible genes in GAS, stopped intracellular accumulation of Cu, and rescued growth of a ΔcopA mutant strain that is impaired in Cu efflux in the presence of added Cu. These findings led us to propose a new role for Hst5 and salivary histatins as major Cu buffers in saliva that reduce the potential negative effects of Cu exposure to microbes. We speculate that histatins promote oral and oropharyngeal health by contributing to microbial homeostasis in these host niches.

show abstract

Section: Discussionmentioning

confidence: 99%

The role of metal binding in the function of the human salivary antimicrobial peptide histatin-5

Stewart

Hong

Holmes

et al. 2022

Preprint

View full text Add to dashboard Cite

show abstract

“…Visual MINTEQ uses a log K value of 0.3 for CuCl and 1.98 for CdCl. However, in aqueous media, log K values as high as ~1 have been reported for CuCl (Sato & Kato, ) and the IUPAC recommended value is 0.83 (Powell et al, ), while for CdCl, log K values as low as 0.5 have been reported (Simoes, Vaz, & Da Silva, ). As some reports of log K values for ZnCl are of the order 0.5, it is possible that the majority of this metal is in the free ion form in the exposure media (Aparicio & Elizalde, ; De Robertis & De Stefano, ).…”

Section: Discussionmentioning

confidence: 99%

The interplay between chemical speciation and physiology determines the bioaccumulation and toxicity of Cu(II) and Cd(II) to Caenorhabditis elegans

Moyson

Town

Joosen

et al. 2018

J of Applied Toxicology

View full text Add to dashboard Cite

Using the well-documented model organism Caenorhabditis elegans, a combined analysis of metal speciation in the exposure medium and body burdens of metals (Zn, Cu and Cd) was performed, and factors that are predictive of toxicological endpoints in single metal and mixed metal exposures were identified. Cu, and to a lesser extent Cd, is found to associate with Escherichia coli in the exposure medium (the food source for C. elegans) as evidenced by the observed decrease in both their dissolved and free metal ion concentrations. Together with a critical analysis of literature data, our results suggest that free metal ion concentrations and thus aqueous uptake routes are the best predictor of internal concentrations under all conditions considered, and of metal toxicity in single metal exposures. Additional factors are involved in determining the toxicity of metal mixtures. In general, the eventual adverse effects of metals on biota are expected to be a consequence of the interplay between chemical speciation in the exposure medium, timescale of exposure, exposure route as well as the nature and timescale of the biotic handling pathways.

show abstract

Chemical Speciation of Environmentally Significant Metals with Inorganic Ligands. Part 2. The Cu²⁺—OH^‐, Cl^‐, CO₃^2‐, SO₄^2‐, and PO₄^3‐ Systems (IUPAC Technical Report)

Abstract: and Systems (IUPAC Technical Report) -[217 refs.]. -(POWELL, K. J.; BROWN, P. L.; BYRNE, R. H.; GAJDA, T.; HEFTER, G.; SJOBERG, S.; WANNER, H.; Pure Appl. Chem. 79 (2007) 5, 895-950; Dep. Chem., Univ. Canterbury, Christchurch, N. Z.; Eng.) -Schramke 40-221

Cited by 2 publications

References 48 publications

The role of metal binding in the function of the human salivary antimicrobial peptide histatin-5

The role of metal binding in the function of the human salivary antimicrobial peptide histatin-5

The interplay between chemical speciation and physiology determines the bioaccumulation and toxicity of Cu(II) and Cd(II) to Caenorhabditis elegans

Contact Info

Product

Resources

About