Antibody against Bacillus thuringiensis phosphatidylinositol-phospholipase C: some examples of its potential uses.

We have purified the phosphatidylinositol-phospholipase C enzyme from the bacterium Bacillus thuringiensis. This enzyme is able to release in soluble form molecules which are anchored to membranes via a glycan-phosphatidylinositol group. It exhibits a molecular weight of 33-35 kDa. We raised polyclonal antisera against the molecule and used them in immunoblot as well as radioimmunoassays for enzyme detection. This last technique should facilitate monitoring of chromatographic steps during enzyme purification. We coupled antibodies to Sepharose beads in order to remove the enzyme from incubation media. This reagent also proved to be particularly useful in control experiments designed to ascertain that the observed release of molecules is due to the action of the phosphatidylinositol-phospholipase C enzyme and not to spontaneous release or to cleavage by nonspecific hydrolases. A search for cross-reactive molecules in other bacterial strains or mammalian tissues gave negative results. This leads to the conclusion that a great diversity exists between phosphatidylinositol-phospholipases C, even among different bacterial strains.