Biomaterial Database

Effects of certain cations (Fe, Zn, Mg, and Ca) on bacterial endotoxins. 1978

J Sourek, and M Tichý, and J Levin

The natural occurrence of cations Fe, Zn, Mg, and Ca in the lipopolysaccharide (LPS) of both the S and R forms of Shigella dysenteriae 1 was studied. LPS preparations were obtained either by phenol-water extraction (according to the method of Westphal et al., Z. Naturforsch. 7b:148-155, 1952) or by extraction of cells with hypertonic sodium chloride-sodium citrate (according to the method of Raynaud and Digeon, C. R. Acad. Sci. (Paris) 229:564-566, 1949), with subsequent chromatographic purification on Sephadex G200 and Sepharose 4B columns. The cation in highest concentration in the Westphal extract was Mg(2+) (as much as 30 mug/mg), and the lowest one was Fe (ca. 0.10 mug/mg). In LPS of the Raynaud type, the cation in highest concentration was Ca(2+) (as much as 13 mug/mg), and the lowest one was Fe (ca. 0.10 mug/mg). The effects of increasing and decreasing the concentrations of cations (Fe, Zn, Mg, Ca) upon the biological activity of the endotoxins was evaluated by using toxicity in mice and the Limulus test. It appeared that increased concentrations of Fe (chiefly of Fe(3+)) decreased the toxicity of the R form of LPS, whereas Mg(2+) decreased the toxicity of the S form. After prolonged dialysis of LPS preparations against deionized water, there was no consistent relationship between toxicity as determined in white mice and with the Limulus test.

UI	MeSH Term	Description	Entries
D007501	Iron	A metallic element with atomic symbol Fe, atomic number 26, and atomic weight 55.85. It is an essential constituent of HEMOGLOBINS; CYTOCHROMES; and IRON-BINDING PROTEINS. It plays a role in cellular redox reactions and in the transport of OXYGEN.	Iron-56,Iron 56
D008070	Lipopolysaccharides	Lipid-containing polysaccharides which are endotoxins and important group-specific antigens. They are often derived from the cell wall of gram-negative bacteria and induce immunoglobulin secretion. The lipopolysaccharide molecule consists of three parts: LIPID A, core polysaccharide, and O-specific chains (O ANTIGENS). When derived from Escherichia coli, lipopolysaccharides serve as polyclonal B-cell mitogens commonly used in laboratory immunology. (From Dorland, 28th ed)	Lipopolysaccharide,Lipoglycans
D008274	Magnesium	A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
D011232	Chemical Precipitation	The formation of a solid in a solution as a result of a chemical reaction or the aggregation of soluble substances into complexes large enough to fall out of solution.	Precipitation, Chemical
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D002413	Cations, Divalent	Positively charged atoms, radicals or groups of atoms with a valence of plus 2, which travel to the cathode or negative pole during electrolysis.	Divalent Cations
D004731	Endotoxins	Toxins closely associated with the living cytoplasm or cell wall of certain microorganisms, which do not readily diffuse into the culture medium, but are released upon lysis of the cells.	Endotoxin
D012762	Shigella dysenteriae	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria that is extremely pathogenic and causes severe dysentery. Infection with this organism often leads to ulceration of the intestinal epithelium.	Bacillus dysenteriae,Bacillus dysentericus,Bacillus shigae,Eberthella dysenteriae,Shigella shigae
D015032	Zinc	A metallic element of atomic number 30 and atomic weight 65.38. It is a necessary trace element in the diet, forming an essential part of many enzymes, and playing an important role in protein synthesis and in cell division. Zinc deficiency is associated with ANEMIA, short stature, HYPOGONADISM, impaired WOUND HEALING, and geophagia. It is known by the symbol Zn.