Barium in Biological Systems

     Barium (Ba) is less notable in biological systems compared to metals such as iron (Fe) or zinc (Zn).  However, there are useful interactions involving barium in biological systems.

     An example of barium's involvement in a biological system is the binding of barium ions to phosphoinositide-specific phospholipase (1).  Barium (and calcium) are used as mediators by bonding to the active sites of the enzymes in the reaction as phospholipase connects phospholips together to form a membrane.

     In another experiment (2), barium salts were used to determine the packing density of phospholipids in the cellular membrane of certain species of bacteria.

     Because of its interactions with phospholipids, a third function of barium in biological systems is the modelling of phospholipid head groups (3).  Barium diethyl phosphate is a model compound used to analyze the head groups of phospholipids.
     From the found materials, it is clear that barium is often used in the arrangement and connection of phospholipids in cellular membranes.


Works Cited:

(1) Lars-Oliver Essen, Olga Perisic, Denise E. Lynch, Matilda Katan, and Roger L. Williams.  A Ternary Metal Binding Site in the C2 Domain of Phosphoinositide-Specific Phospholipase C-δ1. Biochemistry, 1997. Vol. 36, pp. 2753-2762.

(2) Scott Snyder, Dennis Kim, and Thomas J. McIntosh.  Lipopolysaccharide Bilayer Structure:  Effect of Chemotype, Core Mutations, Divalent Cations, and Temperature. Biochemistry. 1999. Vol. 38, pp. 10758–10767.

 

(3) J. Herzfeld, R. G. Griffin, R. A. Haberkorn.  ³¹P chemical-shift tensors in barium diethyl phosphate and urea-phosphoric acid: model compounds for phospholipid head-group studies.  Biochemistry. 1978.  Vol. 17, pp. 2711–2718.