title: Multiple 6-bromotryptophan residues in a sleep-inducing peptide.
abstract: We have characterized a novel sleep-inducing peptide comprising 33 amino acids with three residues of the unusual posttranslationally modified amino acid, 6-bromotryptophan. The peptide, termed "light sleeper" or the r7a conotoxin, was purified from the venom of the fish-hunting Conus radiatus. The light sleeper peptide has additional notable biochemical properties; it equilibrates slowly between two distinct conformers, and has four gamma-carboxyglutamate residues. The pattern of posttranslational bromination in the light sleeper peptide suggests that tryptophan residues at N- and C-termini may be preferential sites for posttranslational bromination.
authors.affiliation: Department of Biology, University of Utah, Salt Lake City, Utah 84112, USA.
authors.forename: Elsie C
authors.initials: EC
authors.lastname: Jimenez
authors.forename: Maren
authors.initials: M
authors.lastname: Watkins
authors.forename: Baldomero M
authors.initials: BM
authors.lastname: Olivera
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002851:Chromatography, High Pressure Liquid; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D008969:Molecular Sequence Data; D008974:Mollusca / Q000737:chemistry; D010455:Peptides / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000494:pharmacology*; D011499:Protein Processing, Post-Translational; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012890:Sleep / Q000187:drug effects*; D014364:Tryptophan / Q000031:analogs & derivatives* / Q000032:analysis*
chemical_list: C110059:6-bromotryptophan; D018076:DNA, Complementary; D010455:Peptides; D012333:RNA, Messenger; D014364:Tryptophan