Toxin-neutralizing effect of antibody against subtilisin-digested tetanus toxin

Different response of the knockout mice lacking b-series gangliosides against botulinum and tetanus toxins

We assessed the response in knockout mice lacking the b-series (G(D2), G(D1b), G(T1b) and G(Q1b)) gangliosides against Clostridium botulinum (types A, B and E) and tetani toxins. We found that botulinum toxins were fully toxic, while tetanus toxin was much less toxic in the knockout mice. Combining the present results with our previous finding that tetanus toxin and botulinum types A and B toxins showed essentially no toxic activity in the knockout mice lacking both the a-series and b-series gangliosides (complex gangliosides), we concluded that the b-series gangliosides is the major essential substance for tetanus toxin, while b-series gangliosides may be not the essential substance for botulinum toxins, at the initial step during the intoxication process in mouse.

Three-dimensional structural analysis of tetanus toxin by electron crystallography

Two-dimensional crystalline arrays of native tetanus toxin have been formed at the interface between a solution of the toxin and a phospholipid monolayer containing a ganglioside. Electron crystallographic analysis has been used to study these periodic arrays. The arrays obey the symmetry of plane group p12(1), with a = 126 A and b = 84 A, and a thickness of 90 A (1 A = 0.1 nm). The three-dimensional structure of tetanus toxin in negative stain is reconstructed to a nominal resolution of 14 A from multiple tilt images. The molecule presents an asymmetric three-lobed structure and could interact with the monolayer in two possible orientations.

A review of the molecular structure of tetanus toxin

A discontinuous preparative polyacrylamide gel electrophoresis system has been developed and used to purify both the nicked and unnicked forms of tetanus toxin. The system was also used to prepare purified H and L chain peptides from the nicked toxin. The results show that the endogenous protease(s), which convert unnicked toxin to the nicked form, produce multiple species of nicked toxin, and heterogeneity in the H and L chains. The major amino termini of the toxins and their peptide components are: extract toxin, proline; filtrate toxin, proline, serine and asparagine; L chain, proline; and H chain, serine and asparagine. The L chain is located in the amino terminal position of the toxin molecule and the H chain the carboxy terminal end. A model is proposed to explain these results. Using the analytical ultracentrifuge, we have determined the molecular weights of extract and filtrate toxins to be 140000 +/- 5000 and 128000 +/- 3000, respectively. Using SDS-polyacrylamide gel electrophoresis we estimate the molecular weights of the H and L chains to be 87000 and 48000 daltons, respectively. Circular dichroic spectra of the toxins and their peptide components indicate that: the major tryptophanyl band in the toxin is contributed almost entirely by the H chain, the microenvironments of all the aromatics and disulfides in the two toxins appear to have small if any differences, the two toxins show little difference in their ordered secondary structure, and the two peptides when separated from one another still retain 80% of the helical structure that is present in the intact toxin but show a considerable loss of beta-structure. The crystalline form of the nicked toxin has a hexagonal symmetry with two dimensional reciprocal lattice constants of 1/150 A-1 and 1/150 A-1. The crystals appear to belong to the two dimensional plane group P6 suggesting that each unit cell contains 6 or a multiple of 6 toxin molecules.