Effects of Certain Cations (Fe, Zn, Mg, and Ca) on Bacterial Endotoxins

Sourek, J; Tichý, M; Levin, Jack

doi:10.1128/iai.21.2.648-654.1978

Cited by 11 publications

(2 citation statements)

References 13 publications

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“…A broad screening of LPS from several sources was beyond the scope of this paper. However, it is worth noting that LPS is known to bind a number of metals (Lewis and Dixon, 1971; Šourek and Tichý, 1975; Šourek et al ., 1978), which are certain to be present in bacterial culture media. Copper contamination of LPS prepared by phenol extraction (such as the lots used in this study) has been previously reported at similar levels to those we describe here (Šourek and Tichý, 1975).…”

Section: Discussionmentioning

confidence: 99%

Redox-active metals in commercial preparations of lipopolysaccharide: implications for studies of cellular responses to bacterial products

et al. 2003

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SummaryThe mechanisms by which lipopolyaccharide (LPS) activates cells have been the subject of intense investigation for many years. Whereas much information on this process has been collected for mammalian species, little is known about the signalling pathways operative in other animals. One general mode of cellular activation that has been recently proposed for pathways independent of the primary mammalian LPS receptor, CD14, involves reactive oxygen species (ROS) as intermediates in LPSinduced signalling pathways. Therefore, we used 2 ¢ ,7 ¢ -dichlorodihydrofluorescein, a fluorogenic probe of redox activity, to examine LPS-induced oxidative responses of a macrophage-like cell line from the rainbow trout, RTS11. Lipopolysaccharide dosedependently increased oxidation of this probe by RTS11 cells, and a variety of other cell lines. This process was inhibited by catalase, superoxide dismutase and N G -methylarginine citrate, an inhibitor of nitric oxide synthases, suggesting the involvement of a diverse assortment of cellular ROS. More careful dissection of this phenomenon led us to conclude that the increase in oxidation was, in fact, due almost entirely to metals, particularly copper, in some LPS preparations, which is something to consider when experimenting with LPS.

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Section: Discussionmentioning

confidence: 99%

Redox-active metals in commercial preparations of lipopolysaccharide: implications for studies of cellular responses to bacterial products

et al. 2003

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“…Cations, including iron, are known to complex naturally with LPS. 21 We reasoned that iron lost from heme in destabilized hemoglobin might become associated with the LPS in the hemoglobin-LPS complexes. In fact, our most recent studies demonstrated saturable binding of iron to LPS.…”

Section: Introductionmentioning

confidence: 99%

Bacterial endotoxin (lipopolysaccharide) stimulates the rate of iron oxidation

Roth

Panter

Zegna

et al. 2000

Journal of Endotoxin Research

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Bacterial endotoxin (lipopolysaccharide) has affinity for a number of cations, including iron. Previous investigations have demonstrated that lipopolysaccharide can affect the oxidation rate of iron; heme-bound ferrous iron in hemoglobin is oxidized to ferric iron when hemoglobin binds lipopolysaccharide. In the present study, we directly examined the interaction between lipopolysaccharide and iron. Lipopolysaccharide caused a concentration-dependent increase in the rate of iron oxidation, with up to a 23-fold increase in oxidation in the presence of 200 µg/ml Escherichia coli lipopolysaccharide. This effect was seen both with several carbohydrate-rich smooth lipopolysaccharides and also with carbohydrate-poor rough lipopolysaccharide. Extensively deacylated rough lipopolysaccharide had no effect, suggesting a role of the fatty acid components of lipopolysaccharide in this process. Purified lipid A produced inconsistent results: some preparations stimulated iron oxidation and others did not. A series of sugars, starches and a preparation of purified O-chain polysaccharide (the carbohydrate portion of the lipopolysaccharide macromolecule) had no effect on the rate of iron oxidation, whereas phospholipid-enriched brain tissue extracts (similar to the lipid A component of lipopolysaccharide) stimulated oxidation. We conclude that the lipid moiety of bacterial lipopolysaccharide is responsible for the stimulation of iron oxidation. This process may contribute to the ability of lipopolysaccharide to cause oxidation of heme-bound iron in hemoglobin.

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Bacterial endotoxins: Comparison of mitogenic, polyclonal, antibody-inducing and toxicity activities

et al. 1991

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The mitogenic effects on mouse spleen lymphocytes were determined in a large series of commercially available and laboratory-prepared lipopolysaccharides (LPS) obtained from Escherichia, Salmonella, Serratia and Shigella species; part of these LPS preparations was chemically modified prior to testing. In order to establish whether the degree of mitogenic activity corresponds with other biological effects of these preparations, polyclonal activity, capability to induce specific antibody formation and toxicity were determined for selected LPS's with different mitogenic effects. Some of the detoxication procedures used succeeded in reducing the toxicity of LPS while preserving its high mitogenic activitione of the Fe-detoxified preparations of LPS (from the R-form of Shigella dysenteriae serovar 1) exhibited a medium-degree efficacy in all parameters studied. Generally, there was no correlation between the degree of mitogenic activity and the polyclonal and antibody-inducing activities, but in some instances polyclonal activity did correlate with the antibody-inducing activity.

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Effects of Certain Cations (Fe, Zn, Mg, and Ca) on Bacterial Endotoxins

Cited by 11 publications

References 13 publications

Redox-active metals in commercial preparations of lipopolysaccharide: implications for studies of cellular responses to bacterial products

Redox-active metals in commercial preparations of lipopolysaccharide: implications for studies of cellular responses to bacterial products

Bacterial endotoxin (lipopolysaccharide) stimulates the rate of iron oxidation

Bacterial endotoxins: Comparison of mitogenic, polyclonal, antibody-inducing and toxicity activities

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