Abstract
The toxic principles of various streptomyces cultures, which are responsible for the desquamation and degeneration of HeLa cell cultures in vitro and the formation of necrosis in the skin of guinea pigs, were shown to be protease in nature. Although an attempt to crystallize one of these principles was unsuccessful, protective effect of calcium ion the activity was established.
Along the line of such studies, the distribution of these proteases in the filtrates of streptomyces culture were examined with a newly designed pulp disc diffusion assay procedure on gelatin- or casein-agar plates. Among the strains subjected to the screening, some 60% produced proteases in the routine culture media used in this laboratory. Although majority was responsible for degeneration of HeLa cells and are basic in nature, the presence of various proteases different in electrophoretic and paper-chromatographic characters as well as in their biological activities was demonstrated. Further classification of these enzymes and their use in streptomyces taxonomy or the use as helminthics were left for the future studies.
