Distribution of superoxide dismutase, catalase, and peroxidase activities among Treponema pallidum and other spirochetes.

Representative members of Spirochaetales were surveyed for their content of superoxide dismutase (SOD), catalase, and peroxidase activities. Only Leptospira exhibited peroxidase activity. Obligately anaerobic cultivable Treponema and Spirochaeta possessed no SOD or peroxidative capabilities. Upon polyacrylamide gel electrophoresis, Spirochaeta aurantia, Borrelia hermsi, and five Leptospira biflexa serovars showed SOD activity associated with one electrophoretic band which was inhibited by H2O2, suggesting that they were iron-containing dismutases. These spirochetes could be distinguished by differences in relative mobilities of their SODs. SOD activity, but not catalase activity, was induced aerobically in S. aurantia. All Leptospira interrogans serovars and two L. biflexa serovars lacked significant SOD activity. These SOD-deficient strains of Leptospira, with one exception, possessed high levels of catalase activity. The Nichols strain of virulent Treponema pallidum possessed SOD and catalase activities, but lacked peroxidase activity. The SOD in T. pallidum exhibited two electrophoretic bands containing copper and zinc, and its relative mobility was identical to that of purified rabbit SOD. Immunization of sheep with purified rabbit SOD resulted in antiserum which inhibited both rabbit SOD and T. pallidum SOD assayed by spectrophotometric analysis or activity staining following polyacrylamide gel electrophoresis. In agarose gel diffusion, precipitin lines of identity were observed between purified rabbit SOD and cell extracts of T. pallidum. These data indicated that the SOD activity detected in T. pallidum was host derived.