[Serological relationships between serylprotease and esterase excreted by "Bacillus subtilis" during sporulation...

During the sporulating phase of Bacillus subtilis an extracellular serylprotease (SPE) and an esterase are excreted. The two enzymes follow the same kinetics of appearance in the culture medium and have some properties in common, in particular both enzymes hydrolyze benzoyltyrosine ethylester and are inhibited by phenylmethylsulfonyl fluoride. This raised the question of a possible structural relationship between the two proteins. A specific antiserum against the SPE was prepared. Using a radioimmunological assay, no reaction with the esterase could be detected. Asporogenous mutants (SpoOA and SpoOB) imparied in the production of both enzymes were analysed. Immunological assays with SPE-specific antiserum supported the hypothesis that the regulation of the biosynthesis of both enzymes would be affected by SpoOA and SpoOB mutations.