Two forms of bacteriolytic endo-N-acetylmuramidase in Acanthamoeba castellanii.

Two different molecular forms of bacteriolytic endo-N-acetylmuramidase (EC 3.2.1.17) were found in the Acanthamoeba castellanii culture. The enzymes were separated by column chromatography on DEAE-Sephadex or by polyacrylamide-gel electrophoresis. In young cultures only one molecular form of the enzyme was selectively secreted by amoeba cells to the environment. The second, more basic enzyme protein was preferentially synthesized by aging Acanthamoeba castellanii cells, and was also liberated to the medium. In amoeba cells the bulk of forms A and B of endo-N-acetylmuramidase are associated with subcellular organelles--lysosomes.