Interaction of spectrin with hydrophobic agaroses

Purified spectrin was found to interact strongly with hydrophobic agaroses such as Phenyl- or Octyl-Sepharose, in the presence of EDTA. From the complexes formed spectrin was eluted with ethylene glycol but not with low ionic strength solutions. The binding capacity of spectrin increased with increasing ionic strength of the equilibration buffer and showed but little dependence on its pH value. The fragments obtained by proteolysis of spectrin carried out under mild conditions were also found to bind strongly to phenyl-agarose, and were eluted with ethylene glycol. The fractions eluted with ethylene glycol contained two closely related polypeptides of Mr 65,000 and 60,000.