title: Isolation and fractionation of cell-free extract from streptolysin-S-forming streptococci.
abstract: A series of procedures have been developed for obtaining a partially purified fractions possessing anticancer activity using live streptolysin S-forming streptococci (Su strain) harvested from their yeast extract-culture fluid. These procedures consist principally of (1) preparing cell-free extract (CFE) from homogenized streptococci, (2) streptomycin-treatment of CFE (S-CFE) to remove nucleic acids, and (3) stepwise fractionations of S-CFE with 0.4, 0.5, 0.6, and 1.0 saturated solutions of ammonium sulfate, each fraction being dialyzed against distilled water followed by lyophilization. The 60-F product, which was precipitated by the 0.6-saturated solution, was found to be the most potent among six products obtained and to be about 4 times more effective than the original CFE in depriving the invasiveness of Ehrlich carcinoma cells in mice. Data on physical and biochemical properties of 60-F product are also presented.
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000302:isolation & purification*; D002286:Carcinoma, Ehrlich Tumor / Q000188:drug therapy*; D002458:Cell Fractionation / Q000379:methods; D002474:Cell-Free System; D051379:Mice; D013297:Streptococcus pyogenes / Q000032:analysis* / Q000378:metabolism; D013301:Streptolysins / Q000096:biosynthesis
chemical_list: D000970:Antineoplastic Agents; D013301:Streptolysins