title: Biochemical and biological properties of Staphylococcal enterotoxin K.
abstract: Staphylococcus aureus is an important human pathogen which is implicated in a wide variety of diseases. Major determinants of the virulence of this organism include extracellular virulence factors. Staphylococcal enterotoxins (SEs) are important causative agents in staphylococcal toxic shock syndrome and food poisoning. Our study identified a novel enterotoxin, SEK, and examined its biochemical and biological properties. SEK had a molecular weight of 26,000 and an experimentally determined pI of between 7.0 and 7.5. SEK was secreted by clinical isolates of S. aureus. We demonstrated that SEK had many of the biological activities associated with the SEs, including superantigenicity, pyrogenicity, the ability to enhance the lethal effect of endotoxin, and lethality in a rabbit model when administered by subcutaneous miniosmotic pump. Recombinant SEK was shown to stimulate human CD4(+) and CD8(+) T cells in a Vbeta-specific manner; T-cells bearing Vbeta 5.1, 5.2, and 6.7 were significantly stimulated to proliferate.
authors: Department of Microbiology, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA.
authors: P M
authors: PM
authors: Orwin
authors: D Y
authors: DY
authors: Leung
authors: H L
authors: HL
authors: Donahue
authors: R P
authors: RP
authors: Novick
authors: P M
authors: PM
authors: Schlievert
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004768:Enterotoxins / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology*; D008213:Lymphocyte Activation / Q000187:drug effects; D008969:Molecular Sequence Data; D011817:Rabbits; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000032:analysis; D011994:Recombinant Proteins / Q000737:chemistry / Q000494:pharmacology; D013211:Staphylococcus aureus / Q000472:pathogenicity*; D018089:Superantigens / Q000494:pharmacology
chemical_list: D004768:Enterotoxins; D016693:Receptors, Antigen, T-Cell, alpha-beta; D011994:Recombinant Proteins; D018089:Superantigens