Phospholipase C bacterial

Eberhard, D. A., Cooper, C. L., Low, M. G. and Holz R. W. Evidence that the inositol phospholipids are necessary for exocytosis loss of inositol phospholipids and inhibition of secretion in permeabilized cells caused by a bacterial phospholipase C and removal of ATR Biochem. J. 268 15-25, 1990. 

A thoughtful and detailed outline of the isolation, purification and characterization of the bacterial phospholipases C is given by Waite (1987). Procedures similar to those mentioned above for the mammalian enzymes were also useful in defining the chemistry of the bacterial phospholipases C. 

In a study designed to investigate the structural features of a phospho-glyceride interaction with a bacterial phospholipase C, El-Sayed et al. (1985), reported that the carbonyl group and its closely related environment are most important. A more detailed treatment of the substrate specificity of this enzyme can be found in an excellent review by Massing and Eibl (1994). 

A bacterial phosphatidylinositol specific phospholipase C (PI-PLC) had been available for many years before it was demonstrated to strip a number of membrane-bound proteins from eukaryotic cell surfaces [1], Such proteins are anchored by a PI moiety in which the 6 position of inositol is glycosidically linked to glucosamine, which in turn is bonded to a polymannan backbone (Fig. 3-10). The polysaccharide chain is joined to the carboxyl terminal of the anchored protein via amide linkage to ethanolamine phosphate. The presence of a free NH2 group in the glucosamine residue makes the structure labile to nitrous acid. Bacterial PI-PLC hydrolyzes the bond between DAG and phosphati-dylinositols, releasing the water-soluble protein polysac charide-inositol phosphate moiety. These proteins are tethered by glycosylphosphatidylinositol (GPI) anchors. 

Essentially the existence of this enzymatic activity was first established with certainty in the early 1940s in the filtrates of the bacterial organism Cl. perfringens (Cl. welchii) and has been detected subsequently in the filtrates of many other bacteria. Sloane-Stanley (1953) first presented evidence supportive of the presence of a phospholipase C in a mammalian cell, the guinea pig brain. Since that time, momentum in this field of study has increased exponentially with the exciting developments in the signal transduction field. In the latter system, stimulation of a cell leads to activation of a phospholipase C,... 

In contrast to the phospholipase C of bacterial origin, there appears to be a consensus that the enzyme from mammalian sources prefers Ca2+ at millimo-lar concentrations. Interestingly, heavy metal ions such as Hg2+ or Zn2+ are strong inhibitors of this source of enzyme and EGTA must be included in the reaction mixture to chelate these cations. 

As illustrated in Table I, many hormones act by stimulating membrane-bound phospholipases. The most commonly affected enzyme is a phospholipase C with specificity for phosphoinositides, i.e., a phosphoinositidase C (PIC) and, among these, the most relevant has specificity for phosphatidylinositol bisphosphate yielding inositol trisphosphate (IP3) and diacylglycerol (DAG). IP3 and DAG act as second messengers to mobilize Ca2+ from intracellular stores and activate the phospholipid- and Ca2+-dependent protein kinase, respectively (protein kinase C) (for reviews see Refs. 87-90). A typical Gp-mediated response of this type occurs in neutrophils exposed to the chemoattractant peptide fMLP [91]. fMLP binds to specific membrane receptors which recognize proteolyzed fragments of bacterial pro-... 

Griffith, O.H., and Ryan, M., 1999, Bacterial phosphatidylinositol-specific phospholipase C Structure, function, and interaction with lipids. Biochim. Biophys. Acta 1441 237-254. 

Lewis, K., Garigapati, V, Zhou, C., and Roberts, M.F., 1993, Substrate requirements of bacterial phosphatidylinositol-specific phospholipase C. Biochemistry 32 8836-8841. 

All aminopeptidases identified so far contain a glycosylphosphatidyl inositol (GPI) moiety through which they anchor to membranes [123,124,143,144]. These GPI-anchored proteins may play an essential role in targeting Cry toxins to lipid raft membrane microdomains and leading to toxin aggregation and pore fimnation [145]. Removal of the GPI-anchor with bacterial or endogenous phospholipase C converts flie membrane-... 

Ruiz-Arguello et al. [91] were the first to point out that generation of ceramides in the bilayer induced efflux of vesicle or cell contents. They treated either large unilamellar vesicles consisting of sphingomyelin, phosphatidylethanolamine and cholesterol (at a 2 1 1 mole ratio), or resealed erythrocyte ghosts, both loaded with low-molecular mass fluorescent dyes, with bacterial SMase. In both cases, rapid efflux ensued in parallel with enzyme activity. This is in contrast with phosphatidylcholine phosphatidylethanolamine cholesterol (2 1 1) vesicles treated with phospholipase C, for which aqueous contents were not released. 

Bacterial phosphatidylinositol-specific phospholipase C (PI-PLC) (reviewed in ref. [51]) or trypanosomal GPI-specific phospholipase C (GPI-PLC) [52-54] releases GPI-anchored proteins from the cell surface leaving behind diacylglycerol. This cleavage not only solubilizes the protein, but also exposes a phosphoinositol-containing cryptic epitope termed cross-reacting determinant [55]. Reactivity of polyclonal antibodies derived against the cross-reacting determinant (CRD) provide additional evidence for the presence of a GPI anchor. 

Wadsworth, S.J., Goldfine, H. Listeria monocytogenes Phospholipase C -dependent Calcium signaling modulates bacterial entry into J774 macrophage-like cells. Infect Immun 1999 67 1770-8... 

Phospholipase C occurs principally in bacterial toxins and snake venoms, but it has been reported in animal tissue (Druzhinina and Kritzman 1952). The enz3mae is able to liberate phosphorylcholine from sphingomyelin (MacFarlane 1948) but not from lysolecithin or GPC (Zamecnik, Brewster and Litmann 1947). 

CIAP is usually prepared from unweaned calf intestinal mucosa. The membrane-bound APase can be selectively released (up to 90%) by treatment with bacterial (S. aureus) phosphatidylinositol-specific phospholipase C (20). Affinity chromatography using a Sepharose-immobilized triazine dye analog that carries a phosphonate-terminal aminobenzene ring yields a 330-fold one-step purification of CIAP from a crude intestinal extract (21). The purity of CIAP, which can be specifically eluted from the column with a 5 mM Pj solution, is reported to be equivalent to that of a commercial high purity preparation. 

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