Localization of the Two l-Asparaginases in Anaerobically Grown Escherichia coli

Abstract One of the two l-asparaginases from anaerobically grown Escherichia coli K-12 was released into the surrounding medium both during the formation of spheroplasts by treatment with lysozyme and ethylenediaminetetraacetate and following osmotic shock. This enzyme, asparaginase II, has previously been shown to be active against the growth of mouse lymphomas and to be an effective inhibitor of cell-free protein synthesis in microbial extracts. In the present communication osmotic shock has been used as the first step in the purification of asparaginase II. The other enzyme, asparaginase I, was not liberated from the cells.