The staphylococcal enterotoxins are single polypeptide chains that contain two half-cystine residues that are cross-linked in the native toxin to form a “cystine” loop. Several amino acid residues involving part of this loop appear to be the same for the different enterotoxins which may represent the toxic site. The other part of the cystine loop may be involved in the antigenicity of the toxin which is the basis for identifying them as enterotoxns A-E. The antigenicty of the enterotoxins varies from the similarity of enterotoxins C1 and C2 which have the same major antigenic site to enterotoxins A and B which are apparently unrelated antigenically.
1Presented as a part of The Seminar on the Staphylococcal Enterotoxins, at the Annual Meeting of the American Society for Microbiology, Miami Beach, Florida, May 6–11, 1973.
2Contribution from the College of Agricultural and Life Sciences, University of Wisconsin, Madison, Wisconsin.