I-Yih Huang

The Amino Acid Sequence of the Staphylococcal Enterotoxins

The staphylococci produce many biologically active substances among which are the staphylococcal enterotoxins, the causative agents of staphylococcal food poisoning. The ingestion of these substances by humans produces a variety of symptoms, the most common being vomiting and diarrhea in 2–6 hr. Although this illness is not a reportable disease in the United States, a large percentage of food-borne illnesses that are reported are caused by the ingestion of staphylococcal enterotoxins.

The preparation and enzymatic digestion of oxidized, reduced, and alkylated enterotoxin B☆

Abstract Reduced carboxymethylated, reduced aminoethylated, and oxidized enterotoxin B have been prepared with almost quantitative yields. Except for the transformation of half cystine to cysteic acid, methionine to methionine sulfone, and possible destruction of tryptophan upon performic acid oxidation, and half cystine to S -carboxymethylcysteine or S -β-aminoethylcysteine on reduction and subsequent alkylation of enterotoxin B no other amino acids were significantly affected. Thr-Cys-Met and Tyr-Glx-Cys have been found to be the sequences around two half cystine residues present in the enterotoxin B molecule by studying partial acid hydrolyzates of the oxidized enterotoxin. Significant differences were found to be present in the digestion rates with trypsin and chymotrypsin. Oxidized enterotoxin B proved to be more susceptible to the enzymatic digestion than reduced alkylated derivatives.