title: Near native binding of a fluorescent serotonin conjugate to serotonin type 3 receptors.
abstract: Described is the synthesis of 5-hydroxytryptamine-tetramethylrhodamine (5HT*); an indole nitrogen linked fluorescent conjugate of serotonin. Through a series fluorescence quenching experiments and experiments in the presence of a known competitive antagonist (Granisetron), it was shown that 5HT* specifically binds to purified homo-pentameric type-3 human serotonin receptors (5HT(3A)). The measured dissociation constant and Hill coefficient are K(d) = 83 ± 3 nM and n = 3.1 ± 0.3, respectively which is indicative of multi-ligand binding and cooperativity similar to that of unconjugated serotonin.
authors.affiliation: Washington State University, Department of Chemistry, P.O. Box 644630, Pullman, WA 99164-4630, USA.
authors.forename: Elsa I
authors.initials: EI
authors.lastname: Silva-Lopez
authors.forename: Adam O
authors.initials: AO
authors.lastname: Barden
authors.forename: James A
authors.initials: JA
authors.lastname: Brozik
mesh_terms: D005453:Fluorescence; D006801:Humans; D011485:Protein Binding; D044406:Receptors, Serotonin, 5-HT3 / Q000737:chemistry* / Q000378:metabolism; D012235:Rhodamines / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism; D012701:Serotonin / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism
chemical_list: C581847:5-hydroxytryptamine-tetramethylrhodamine; D044406:Receptors, Serotonin, 5-HT3; D012235:Rhodamines; D012701:Serotonin