Fractionation of Phenol Extracts from Brucella suis: Separation of Multiple Biologically Active Components

Brucella suis endotoxin prepared by a modification of Westphal's method was purified further by gel filtration and ion-exchange chromatography. The latter proved to be the most effective means of separating antigenic components associated with this fraction. All of the toxic activity was located in a single peak from carboxymethyl-Sephadex. Subsequent separation of this material on diethylaminoethyl (DEAE)-Sephadex indicated the presence of two or more toxic components in phenol extracts of B. suis. A factor which increases vascular permeability was separated by use of the ion exchanger DEAE-Sephadex, and was associated with the first peak. Its manifestations could be destroyed by heating at 60 C for 30 min or neutralized by reaction with specific antiserum. This permeability factor is believed to be distinct from other toxins which appear in column eluates and which can be assayed by skin induration.