Purification and biochemical characterization of a basic superantigen (SPEX/SMEZ3) from Streptococcus pyogenes.
A potent basic superantigen (designated streptococcal pyrogenic exotoxin X, SPEX/SMEZ3) was purified to homogeneity from culture supernatants of a Streptococcus pyogenes scarlatina strain of type 12 (genotype speA(-), speC(-)) and characterized. Sequence alignments revealed SPEX to be an allele of the streptococcal mitogens type Z (SMEZ). The N-terminal amino acid sequence of SPEX was found with LEVDNNSLLR to be identical to the recently described acidic superantigen SMEZ. Although SPEX/SMEZ genes were present in all of the streptococcal strains tested, a toxin production could only be detected in a small number of strains. The produced toxin concentration in the culture supernatants of positive strains differed between 0 and 20 ng ml(-1). The purified SPEX stimulated human T-lymphocytes with Vbeta8 specificity at extremely low concentrations (lower than 100 pg ml(-1)).
Institute of Medical Microbiology, Friedrich-Schiller-University Jena, Semmelweisstr, Jena, Germany. i9gedi@rz.uni-jena.de
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Gerlach
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Fleischer
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Wagner
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Schmidt
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Vettermann
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Reichardt
D000595:Amino Acid Sequence; D000942:Antigens, Bacterial / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D001427:Bacterial Toxins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D002847:Chromatography, Agarose; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D005098:Exotoxins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D007525:Isoelectric Focusing; D008213:Lymphocyte Activation; D008934:Mitogens / Q000302:isolation & purification* / Q000494:pharmacology; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D016415:Sequence Alignment; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013297:Streptococcus pyogenes / Q000235:genetics / Q000276:immunology*; D013601:T-Lymphocytes / Q000187:drug effects
D000942:Antigens, Bacterial; D001427:Bacterial Toxins; D005098:Exotoxins; D008934:Mitogens; C107894:mitogenic exotoxin Z protein, Streptococcus