Amino Acid Analysis and Molecular Weight Determination of Tetanus Toxin

Abstract

A procedure for the isolation of tetanus toxin was developed. The toxin was precipitated with ammonium sulfate and further purified by use of molecular sieve chromatography and preparative disc gel electrophoresis. The degree of purification resulting from these fractionation procedures was monitored by analytical poly-acrylamide gel electrophoresis, immunodiffusion, and immunoelectrophoresis, all three of which demonstrated a single component. There was a 50-fold increase in specific activity between the crude culture filtrate and the final purified product, which had an average specific activity of 300 × 10 6 mouse minimal lethal doses per mg of N. A molecular weight of 140,000 was estimated by gel filtration on Bio-Gel P-200. A complete amino acid analysis of tetanus toxin is presented.

Tetanus toxin.

“…Proc. ), others identified either leucine or glycine as the single amino-terminal residue (5,52). More recently, this problem has been reexamined by Helting et al (communication to the Int.…”

“…In the last two decades, the toxin has been isolated in a homogeneous state (12,21,22,52,65,73), and its physical and chemical characteristics have been defined in various laboratories in different parts of the world (5,12,14,20,22,50,52,63,64,73,83,85; S. G. Murphy, T. H. Plummer, and K. D. Miller, Fed. Proc., p. 268, 1968).…”

Botulinal toxins and the problem of nomenclature of simple toxins.

“…Newest evidence on the nature of the tetanal toxin is that it is a simple protein of about 150,000 daltons with a sedimentation coefficient of 7S (4,5,26). Although the molecule might eventually be proven to be made up of several polypeptide chains, it does not occur as a polymer of a monomer.…”