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A simple procedure for the purification of staphylococcal alpha-toxin
Acta Pathologica Et Microbiologica Scandinavica. Section B, Microbiology
|December 1, 1976
Summary
This study details the purification of staphylococcal alpha-toxin using heat precipitation and electrophoresis. Optimal conditions were identified for isolating the toxin, revealing its molecular weight and antigenic relationships.
Area of Science:
- Microbiology
- Protein Biochemistry
Background:
- Staphylococcal alpha-toxin is a key virulence factor produced by Staphylococcus aureus.
- Understanding its purification is crucial for studying its biological activity and developing countermeasures.
Purpose of the Study:
- To develop a method for purifying staphylococcal alpha-toxin.
- To characterize the purified toxin and identify related proteins.
Main Methods:
- Production of alpha-toxin using Staphylococcus aureus strain Wood 46 in a casein-based medium.
- Heat precipitation of bacterial culture supernatants at varying pH levels (4.0-7.0).
- Electrophoresis in 8 M urea at pH 8.6 for purification and characterization.
Main Results:
- Heat precipitation effectiveness and toxin inactivation were pH-dependent.
- Optimal precipitation at pH 6.0-7.0 yielded a higher relative amount of alpha-toxin with partial inactivation.
- Purified alpha-toxin has a molecular weight of 39,000 and a minor component with a pI of 7.4.
- A non-haemolytic protein (MW 27,500) showed antigenic relationship to alpha-toxin.
Conclusions:
- pH-controlled heat precipitation is effective for concentrating staphylococcal alpha-toxin.
- Electrophoresis in 8 M urea enables purification and characterization of alpha-toxin.
- Identified a related non-haemolytic protein, suggesting potential toxin precursor or variant.