Solubilization of a 5-HT3 binding site from rabbit small bowel muscularis membranes.
A 5-HT3 binding site, with high affinity for (S-)[3H]zacopride, was solubilized from rabbit small bowel muscularis membranes utilizing 0.5% sodium cholate and 400 mM (NH4)2SO4. Approximately 72% of the (S-)[3H]zacopride binding activity was recovered in a form that retained the high affinity (Kd = 0.7 nM) and specificity for this radioligand that is characteristic of the membrane-bound receptor. ICS 205-930 and other 5-HT3 compounds were effective inhibitors and exhibited the same rank order of potency in the solubilized and membrane-bound preparations. The receptor-detergent complex did not sediment after centrifugation for 1 h at 150,000 x g and eluted between thyroglobulin (MW = 669,000) and apoferritin (MW = 443,000) when fractionated by high-performance liquid chromatography gel filtration. This is the first report of the solubilization of a 5-HT3 binding site.
Gordon
J C
JC
Department of Molecular Biology, A.H. Robins Research Laboratories, Richmond, VA 23261-6609.
Sarbin
N S
NS
Barefoot
D S
DS
Pinkus
L M
LM
D000818:Animals; D001549:Benzamides / Q000378:metabolism / Q000493:pharmacokinetics; D001643:Bridged Bicyclo Compounds / Q000378:metabolism / Q000493:pharmacokinetics; D019086:Bridged Bicyclo Compounds, Heterocyclic; D002851:Chromatography, High Pressure Liquid; D003902:Detergents; D066298:In Vitro Techniques; D008566:Membranes / Q000378:metabolism; D009130:Muscle, Smooth / Q000032:analysis*; D011817:Rabbits; D011985:Receptors, Serotonin / Q000302:isolation & purification*; D012702:Serotonin Antagonists / Q000378:metabolism / Q000493:pharmacokinetics; D012995:Solubility
D001549:Benzamides; D001643:Bridged Bicyclo Compounds; D019086:Bridged Bicyclo Compounds, Heterocyclic; D003902:Detergents; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; C055971:zacopride