A STUDY OF THE HEMAGGLUTININ OF CLOSTRIDIUM BOTULINUM

Abstract : The hemagglutinin of type A toxin behave in gel filtration chromatography like a high molecular weight substance, separating into two peaks of hemagglutination activity that may be related as monomer and dimer. There was no relationship between the ultraviolet absorption of hemagglutinin solutions and the hemagglutination activity. Amino acid analyses were performed on partially purified mixtures of neurotoxin and hemagglutinin, a high molecular weight component free of hemagglutinin, a related high molecular weight component with the greatest hemagglutination activity of the chromatogram, and crystalline toxin. There were close similarities in amino acid composition. The hemagglutinin probably contains little tryptophan because of the independence from ultraviolet absorbance. The absence of methionine in the initial high molecular weight peak suggests that it is maybe a nontoxic impurity. The concentration of hemagglutinin in the partially purified toxin-hemagglutinin complex is estimated at 1% by weight. The hemagglutinin probably is a protein, in agreement with other hemagglutinins, but this fact must be firmly established. It would be unwise to depend on identification of botulinum toxin by its property of hemagglutination, because this activity can be easily removed without seriously diminishing the toxicity.