Chromatography and partial purification of solubilized opiate receptors

Sheep brain membrane opiate receptors were solubilized using two different approaches: (A) Chaps was used to solubilize [3H]buprenorphine labeled membranes. Macromolecular labeled material had a stokes radius of approximately 90 A. Treatment with phospholipase A2, but not phospholipase C, decreased the stokes radius to 50 A indicating the presence and eventual structural role of phospholipids in the solubilized opiate receptor complex. (B) Digitonin-NaCl was used for solubilization of receptors which were then labeled with [3H]diprenorphine. This complex could be chromatographed on hydroxylapatite, DEAE-sepharose and phenylboronate gels successively permitting an approximately 100-fold purification over the solubilized starting material.