THE PRODUCTION, CONCENTRATION, AND PARTIAL CHARACTERIZATION OF STREPTOLYSIN 01

Streptolysin 0 is the oxygen-labile hemolysin present in broth filtrates after the growth of hemolytic streptococci. Neill and Mallory (1926) studied the effect of exposure of this lysin to oxygen and reported that, depending on the age of the culture and other factors, Streptolysin 0 existed in broth filtrates in two forms. These were the reduced hemolytically active form and a reversibly oxidized inactive form which could be reactivated by the addition of a suitable reducing agent. They showed that under some conditions oxidation of the lysin proceeded to such a degree that it was no longer reversible, and under these circumstances its hemolytic activity was com-pletely lost. A partially successful method of concentration of Streptolysin 0 by means of ammonium sulfate fractionation was reported by Smythe and Har-ris (1940). No record of their recoveries was given, but undoubtedly some purification was achieved. Analyses of their preparations were those typical of proteins. Sulfur was present to the extent of 1.9 per cent, partly as SH groups, partly as sulfate sulfur, and partly in an unidentified form. These authors, as well as others, have postulated that the reversible oxidation-reduction properties of the lysin could be accounted for in terms of a reversible sulfhydryl system. Todd (1932a,b; 1938a,b) demonstrated the antigenic properties of the lysin as well as other characteristics which clearly distinguished it from Streptolysin S. Herbert and Todd (1941) pub-lished a method for its isolation and concentration which again depended on fractionation with 1 Part of the material here reported was use