3‐[(3‐Cholamidopropyl)dimethylammonio]‐1‐Propane Sulfonate‐Solubilized Binding Sites for 2‐[125I]Iodomelatonin in Chick Brain Retain Sensitivity to Guanine Nucleotides

Binding of 2-[125I]iodomelatonin to 3-[(3-cholamidopropyl)dimethylammonio]-1-propane sulfonate (CHAPS)-solubilized sites from chick forebrain was rapid. reversible, saturable, of high affinity, and of pharmacological selectivity. Scatchard analyses showed that 2-[125I]iodomelatonin binds to a single site with equilibrium dissociation constant (KD) values of 328 +/- 22 (n = 4) and 302 +/- 26 pM (n = 3) and a maximal number of binding sites …