Comparison of progenitor toxins of nonproteolytic with those of proteolytic Clostridium botulinum Type B.

A nonproteolytic strain of Clostridium botulinum type B produces two toxins of different molecular weight (16S and 12S) that are indistinguishable from the corresponding toxins of a proteolytic strain in molecular weight and construction but differ in potential toxicity, activation ratio, and hemagglutinability. Successful hybridization between the toxic and nontoxic components (both7S) of 12S toxins of biologically heterologous type B strains confirmed the physico-chemical similarity between the toxic as well as the nontoxic components.