Reconstitution of tetanus neurotoxin from, two antigenically active polypeptide fragments

Abstract Whole tetanus toxin indistinguishable from the undissociated toxin (molecular weight 160,000), in terms of molecular weight, electrophoretic behavior, antigenicity, and toxicity, was reconstituted. This was achieved by removal of urea and dithiothreitol (DTT) by dialysis from a mixture of freshly purified fragment α (molecular weight 53,000) and fragment β (molecular weight 107,000) in buffer containing 2 M urea and 1 mM DTT. The highest yield (almost 100%) of reconstituted toxin was obtained when the two isolated fragments were mixed in a molar ratio of 1:1. No toxin was reconstituted from either one of two fragments alone.