ANTI-TUMOR ACTIVITY OF PROTOPLAST MEMBRANE FROM GROUP-A STREPTOCOCCUS

  • 1 January 1977
    • journal article
    • research article
    • Vol. 47  (5) , 341-349
Abstract
Cytoplasmic membrane of Group A Streptococcus [haemolyticus] was obtained by treatment of the cells with a phage-associated lytic enzyme to dissolve the streptococcal cell wall, followed by shocking osmotically. The protoplast membrane fraction (PMF) remained as a distinct homogeneous structure in EM, and analysis showed a low rhamnose content. Febrile response [in rabbits] produced by PMF was very slightly exhibited or not at all. PMF showed weak suppression against the growth of rat Yoshida sarcoma cells in culture and inhibition of [3H]-uridine incorporation into the sarcoma cells in vitro. In vivo antitumor experiments demonstrated that PMF has a mild inhibiting effect against mouse Ehrlich ascites carcinoma, though there was not a definite correlation between survival rate and dose level. Antitumor activity of PMF was thermo-labile and was strikingly abolished by treatment with the bacterial enzyme Nagarse [Bacillus subtilis], but not so much by .alpha.-chymotrypsin [bovine pancreas].