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MULTIPLE FORMS OF STAPHYLOCOCCAL α‐TOXIN
Author(s) -
DALEN ARE B.
Publication year - 1975
Publication title -
acta pathologica microbiologica scandinavica section b microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.909
H-Index - 88
eISSN - 1600-0463
pISSN - 0304-131X
DOI - 10.1111/j.1699-0463.1975.tb00139.x
Subject(s) - chemistry , chromatography , trichloroacetic acid , sephadex , toxin , isoelectric focusing , electrophoresis , elution , isoelectric point , molecular mass , biochemistry , enzyme
A group of proteins was readily extracted at neutrality from trichloroacetic acid precipitates of staphylococcal culture filtrate supernatants, while α‐toxin was dissolved and activated by treating the precipitate with 8 M urea, with acidic buffers or by heating to 90–100° C at neutrality. Heat activation of the precipitate produced a relatively pure α‐toxin with a molecular weight of 39,000. α‐Toxin was eluted together with three other proteins on hydroxyl apatite chromatography, and evidence was obtained for an association between the four proteins. On isoelectric focusing a haemolytic fraction was obtained at pH 6.2, probably due to acid activation of the precipitate formed at the cathodic end of the column. The α‐haemolytic fractions with pI's of 7.4 and 8.6 were shown to consist of α‐toxin only when analyzed by acrylamide electrophoresis in the presence of sodium dodecyl sulphate. The haemolytic component with a pI of 9.2 contained two additional components of molecular weights of 27,500 and 18,000. Chromatography of this material on Sephadex G‐200 showed that α‐toxin and the two proteins appeared as a high molecular complex.