Chemical Characterization of Tetanus Toxin and Toxoid

Abstract

The amino acid analysis of tetanus toxin as purified from bacterial extracts or from culture filtrates of Plectridium tetani , was carried out. The results that have been obtained support the assumption of the identity of both types of toxin. Tetanus toxoid amino acid composition was comparatively determined. Significant decreases in the amounts of some amino acids were found. These deficits are accounted for within the reactions with formaldehyde which lead to the formation of Mannich‐like derivatives. The presence of 6 free SH‐groups on the molecule of toxin could be substantiated. Two of these groups are difficult to reveal. The existence of two disulfide bridges was established. These results are discussed, in particular, with regard to the expression of the toxicity. The presence of only one N‐terminal amino acid residue could be revealed.