title: Synthesis and characterization of photolabile derivatives of serotonin for chemical kinetic investigations of the serotonin 5-HT(3) receptor.
abstract: A series of photolabile o-nitrobenzyl derivatives of serotonin (caged serotonin) were synthesized: the amine-linked serotonin derivatives N-(2-nitrobenzyl) serotonin (Bz-5HT) and N-(alpha-carboxy-2-nitrobenzyl) serotonin (N-CNB-5HT), and O-alpha-carboxy-2-nitrobenzyl) serotonin (O-CNB-5HT), which has the caging group attached to the phenolic OH group. All the derivatives released free serotonin when excited by 308-nm or 337-nm laser pulses. The time constant of serotonin release from N-CNB-5HT was 1. 2 ms, with a quantum yield of 0.08. This is too slow for rapid chemical kinetic measurements. O-CNB-5HT is suitable for transient kinetic investigations of the serotonin 5-HT(3) receptor. It released serotonin with a time constant of 16 micros and a quantum yield of 0.03. The biological properties of O-CNB-5HT were evaluated, and the applicability of the compound for kinetic studies of the 5-HT(3) receptor was demonstrated. O-CNB-5HT does not activate the 5-HT(3) receptor by itself, nor does it modulate the response of a cell when co-applied with serotonin. When irradiated with a 337-nm laser pulse, O-CNB-5HT released free serotonin that evoked 5-HT(3) receptor-mediated whole-cell currents in NIE-115 mouse neuroblastoma cells.
authors.affiliation: Molecular Biology and Genetics, 216 Biotechnology Building, Cornell University, Ithaca, New York 14853-2703, USA.
authors.forename: H G
authors.initials: HG
authors.lastname: Breitinger
authors.forename: R
authors.initials: R
authors.lastname: Wieboldt
authors.forename: D
authors.initials: D
authors.lastname: Ramesh
authors.forename: B K
authors.initials: BK
authors.lastname: Carpenter
authors.forename: G P
authors.initials: GP
authors.lastname: Hess
mesh_terms: D000818:Animals; D007700:Kinetics; D007834:Lasers; D051379:Mice; D009447:Neuroblastoma; D009578:Nitrobenzenes / Q000138:chemical synthesis; D018408:Patch-Clamp Techniques; D010782:Photolysis; D011985:Receptors, Serotonin / Q000737:chemistry*; D044406:Receptors, Serotonin, 5-HT3; D012701:Serotonin / Q000031:analogs & derivatives* / Q000494:pharmacology; D013053:Spectrophotometry; D014407:Tumor Cells, Cultured
chemical_list: D009578:Nitrobenzenes; D011985:Receptors, Serotonin; D044406:Receptors, Serotonin, 5-HT3; D012701:Serotonin