COMPARATIVE GEL FILTRATION OF TOXIN PRECURSOR AND TRYPSIN-ACTIVATED TOXIN OF CLOSTRIDIUM BOTULINUM TYPE E

Sakaguchi, Genji (National Institute of Health, Tokyo, Japan),Sumiko Sakaguchi, and Nobuko Imai . Comparative gel filtration of toxin grecursor and trypsin-activated toxin ofClostridium botulinum type E. J. Bacteriol.87: 401–407. 1964.—Precursor of type E botulinus toxin was highly purified from bacterial cells by extraction, ammonium sulfate precipitation, ribonuclease digestion, and chromatography on CM-Sephadex. The sample free from ribonucleic acid had a toxicity of 5.1 × 105 ld 50 per mg of nitrogen before activation and 8.3 × 107 ld 50 per mg of nitrogen after activation. This precursor and its activated product were subjected to gel filtration on a column of Sephadex G-200. No evidence for smaller fractions was obtained. Both precursor and trypsin-activated toxin were eluted in the void volume with 0.05 or 1m acetate buffer (pH 6.0) or with 0.05 or 0.5m phosphate buffer (pH 7.5). Intact trypsin and its degradation products were separated from toxin. The toxins eluted with the acetate buffers had potencies of 1.2 × 108 and 1.3 × 108 ld 50 per mg of N, while those eluted with the phosphate buffers showed lower toxicities. Possible mechanisms involved in the activation process are discussed.