Mechanism of protection of cells by spermine against lysozyme-induced lysis.

Grossowicz, Nathan (Hebrew University Hadassah Medical School, Jerusalem, Israel) and Miriam Ariel. Mechanism of protection of cells by spermine against lysozyme-induced lysis. J. Bacteriol. 85:293-300. 1963.-Spermine (1 to 5 x 10(-3)m) was found to prevent lysis of Micrococcus lysodeikticus cells by lysozyme. This protection is due to the rapid and efficient stabilization by spermine of the protoplasts formed by lysozyme, and not to interference with the enzymatic activity. This conclusion concerning the spermine effect is based on chemical and microscopic evidence: (i) the amount of hexosamine, released from lysozyme-treated cells, was equal to or even higher in the presence of spermine than in its absence; (ii) microscopic and electron microscopic pictures showed clearly that the spermine-protected structures resembled protoplasts. On the other hand, the "spermine protoplasts" showed a high stability against hypotonic conditions in comparison with "sucrose protoplasts." The spermine-protoplast complex was very stable and could not be destroyed by water and various agents (NaCl, KCl, MgCl(2), cadaverine, and putrescine). A number of bases such as histamine, d-histidine, and streptomycin exhibited an effect similar to that of spermine, while diamines like cadaverine, putrescine, basic amino acids (lysine, arginine, l-histidine), as well as cations like magnesium, were virtually inactive.