Binding of magnesium ions to cell walls of Bacillus subtilis W23 containing teichoic acid or teichuronic acid

Abstract

When grown in a chemostat under various nutritional conditions, cells of Bacillus subtilis W23 produce walls containing teichoic acid or teichuronic acid. The binding of Mg2+ to these walls and to the isolated anionic polymers in solution was measured by equilibrium dialysis. In solution the ribitol teichoic acid bound Mg2+ in the molar ratio Mg2+/P=1:1 with an apparent association constant (Kassoc.) of 0.61 X 10(3)M-1, and the teichuronic acid bound Mg2+ in the ratio Mg2+/CO2-=1.1, Kassoc.=0.3 X 10(3)M-1. Cell walls containing teichuronic acid exhibited closely similar binding properties to those containing teichoic acid; in both cases Mg2+ was bound in the ratio Mg/P or Mg/CO2- of 0.5:1 and with a greater affinity than displayed by the isolated polymers in solution. It was concluded that Mg2+ ions are bound bivalently between anionic centres in the walls and that the incorporation of teichoic acid or teichuronic acid into the walls gives rise to similar ion-binding and charged properties. The results are discussed in relation to the possible functions of anionic polymers in cell walls.

A Continuum of Anionic Charge: Structures and Functions ofd-Alanyl-Teichoic Acids in Gram-Positive Bacteria

“…From a series of covalent modifications of walls from B. subtilis 168, it was concluded that while both TA and peptidoglycan each contribute sites for binding metal cations, the latter would appear to provide a larger fraction (55,131,324,453). In contrast, Heckels et al (212) found that the WTA provides the larger fraction of anionic binding sites in B. subtilis W23, an organism with poly(Rbo-P) WTA. WTA and teichuronic acids are the prime sites of metal binding in B. licheniformis (52).…”

Teichoic Acid Is an Essential Polymer in Bacillus subtilis That Is Functionally Distinct from Teichuronic Acid

“…186, 2004 TEICHOIC ACID IS ESSENTIAL UNDER PHOSPHATE LIMITATION 7871 teichoic acid. The two polymers have been shown to bind magnesium ions with nearly identical affinities (19) and to regulate autolysins by a proton motive force (10). However, teichoic acid may play a unique role that teichuronic acid cannot play.…”

“…Various functions of wall teichoic acid have been proposed, and many of them are related to its anionic character, such as cell shape maintenance by charge repulsion (34) or buffering of magnesium ions (19). However, the ability of teichoic acid to act as a phosphate reservoir appears to present an exception to its indispensability.…”

Accumulation of lead byAnabaena cylindrica : Mathematical modeling and an energy dispersive X-ray study

“…A small but significant portion of some metals accumulated in active cyanobacteria is concentrated inside the cell (Baxter and Jensen, 1980;Jensen et al, 1982Jensen et al, , 1986Pettersson et al, 1985aPettersson et al, , 1988Rachlin et al, 1984;Singh et al, 1992Singh et al, , 1993. In contrast, for many other species, cell wall accumulation is the only significant form of sequestration (Beveridge and Fyfe, 1985;Heckels et al, 1977;Hoyle and Beveridge, 1984;Macaskie, 1990;Macaskie et al, 1987).…”