Identification and purification of a new staphylococcal enterotoxin, H.
A staphylococcal enterotoxin which elicited an emetic response in monkeys but did not share antigenic determinants with any of the identified enterotoxins was identified and purified from Staphylococcus aureus FRI-569. The emetic activity of this new enterotoxin was neutralized only by antibodies specific to it and not by antibodies to enterotoxins A, B, C, D, and E or toxic shock syndrome toxin 1. Immunodiffusion assays did not detect cross-reactivity between this new and all the other identified enterotoxins. The purification procedure involved removal of the enterotoxin from culture supernatant fluids by batch adsorption with CG-50 resin, CM-Sepharose FL ion-exchange chromatography, and Sephacryl 100 HR and Bio-Gel P-30 gel filtration. The molecular weight of this enterotoxin, 27,300, determined by gel filtration on Sephacryl 100 HR agreed with the molecular weight, 28,500, determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The apparent migration of this enterotoxin determined by SDS-PAGE did not shift in the presence of a disulfide reducing agent, indicating that it is composed of a single-chain protein. The N-terminal amino acid sequence of the enterotoxin was determined to be Glu-Asp-Leu-His-Asp-Lys-Ser-Glu-Leu-Thr-Asp-Leu-Ala-Leu-Ala-Asn-Ala-Tyr- Gly- Gln-Tyr-Asn-His-Pro-Phe-Ile-Lys-Glu-Asn-Ile, which did not match the N-terminal sequences of any known proteins. The isoelectric point of the enterotoxin determined by isoelectric focusing was about 5.7.(ABSTRACT TRUNCATED AT 250 WORDS)
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Department of Food Microbiology and Toxicology, Food Research Institute, University of Wisconsin, Madison 53706, USA.
Wong
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AC
D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D004768:Enterotoxins / Q000235:genetics / Q000302:isolation & purification* / Q000633:toxicity; D005779:Immunodiffusion; D008253:Macaca mulatta; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009500:Neutralization Tests; D013211:Staphylococcus aureus / Q000737:chemistry* / Q000235:genetics; D014839:Vomiting / Q000139:chemically induced
D004768:Enterotoxins