Hydrophobic interaction of extracellular protein A from Staphylococcus aureus with octyl-sepharose CL-4B

Extracellular Protein A from Staphylococcus aureus was shown to bind to alkyl agarose adsorbents of different carbon chain length. Octyl-Sepharose CL-4B was chosen to purify the active material, as the strong interaction with this adsorbent allowed the separation of Protein A from the bulk of the contaminants. Protein A retained its ability to bind to IgG in the presence of up to 3.5 M ethylene glycol as demonstrated by hemagglutination. A theory on the possible involvement of hydrophobic interaction in the binding reaction of Protein A to IgG is advanced.