SOLUBILIZATION AND CHARACTERIZATION OF ACTIVE OPIATE BINDING-SITES FROM MAMMALIAN BRAIN

  • 1 January 1982
    • journal article
    • research article
    • Vol. 222  (3) , 629-634
Abstract
Active opiate binding sites were solubilized from cell membranes derived from mammalian brain. High-affinity stereospecific binding to soluble sites was demonstrable when membranes from rat brain, human frontal cortex, whole toad (Bufo marinus) brain, chicken brain minus cerebellum, and bovine corpus striatum were treated with digitonin or glycodeoxycholate, provided that the binding assay was conducted at .ltoreq. 25.degree. C and in the presence of 50-100 mM NaCl. The yield of solubilized binding sites extracted from brain cell membranes was increased substantially (up to 43% yield from bovine striatum) when membranes were treated with detergent solutions containing 0.5-1.0 M NaCl. This effect was not observed when LiCl, KCl or (NH4)2SO4 were substituted for NaCl. Evidence for the solubility of the binding sites was provided by 2 criteria: nonsedimentation after 2 h of centrifugation at 105 .times. g and an apparent MW of 3-4 .times. 105 as determined by gel filtration.