Tetanus neurotoxin was depleted of its catalytic Zn2+ ion, and the apotoxin was reconstituted with different transition metal ions. The Mn2+- and Co2+-tetanus neurotoxins are highly active in the proteolysis of vesicle-associated membrane protein/synaptobrevin, the natural substrate of this toxin, whereas Cu2+ and Fe2+ minimally supported proteolytic activity. The visible absorbance spectrum of...

Tetanus neurotoxin (molecular weight approximately 160,000) was purified from bacterial extracts (intracellular toxin) and mildly trypsinized and from culture filtrates (extracellular toxin). Both purified preparations could be dissociated reversibly into two polypeptide chains, with molecular weights of 53,000 (fragment alpha) and 107,000 (fragment beta), by treatment with 100 mM dithiothreito...

A number of papers from this laboratory have traced the development of a medium for the production of highly potent tetanus toxin, the basis of which is a pancreatic digest of casein (l-3). Considerable work has been done in an effort to identify those components of the digest essential for toxin production, and it has been shown that at least some of these materials are peptides (4, 5). In the...

We compared the ability of Salmonella enterica serovar Typhimurium SL1344 aroA aroD (BRD509) and aroA htrA (BRD807) mutants to act as live vectors for delivery of fragment C of tetanus toxin (FrgC). FrgC was expressed in these strains from either pTETnir15 or pTEThtrA1. BRD509FrgC(+) strains elicited approximately 2-log-higher serum anti-FrgC antibody titers than BRD807FrgC(+) strains. All mice...

Conventionally, for estimation of potency of tetanus toxoid by Antibody Induction Method (AIM), two doses (1/10 th of single human dose/dose) of tetanus toxoid given on 0 th and 28 th day, injected subcutaneously into guinea pigs has been recommended. But this assay has a serious drawback of ‘booster effects’ as the animal is immunized on two occasions besides usage of large number of animals. ...

Protease activity has been demonstrated in culture supernatants of Clostridium tetani at various stages of fermentation. Gel chromatography of the concentrated filtrates revealed the presence of three enzymatically active fractions eluting at separate positions off the column. The smallest protease was found to “nick” the single chain intracellular tetanus toxin, producing the extracellular, tw...