title: Development of an orexin-2 receptor selective agonist, [Ala(11), D-Leu(15)]orexin-B.
abstract: Investigation of L-alanine and D-amino acid replacement of orexin-B revealed that three L-leucine residues at the positions of 11, 14, and 15 in orexin-B were important to show selectivity for the orexin-2 receptor (OX(2)) over the orexin-1 receptor (OX(1)). L-Alanine substitution at position 11 and D-leucine substitution at positions 14 and 15 maintained the potency of orexin-B to mobilize [Ca(2+)](i) in CHO cells expressing the OX(2), while their potency for the OX(1) was significantly reduced. In combined substitutions, we identified that [Ala(11), D-Leu(15)]orexin-B showed a 400-fold selectivity for the OX(2) (EC(50)=0.13nM) over OX(1) (EC(50)=52nM). [Ala(11), D-Leu(15)]orexin-B is a beneficial tool for addressing the functional roles of the OX(2).
authors.affiliation: Banyu Tsukuba Research Institute, Banyu Pharmaceutical Co., Ltd., Okubo-3, Tsukuba 300-2611, Ibaraki, Japan.
authors.forename: Shuichi
authors.initials: S
authors.lastname: Asahi
authors.forename: Shin-Ichiro
authors.initials: S
authors.lastname: Egashira
authors.forename: Masao
authors.initials: M
authors.lastname: Matsuda
authors.forename: Hisashi
authors.initials: H
authors.lastname: Iwaasa
authors.forename: Akio
authors.initials: A
authors.lastname: Kanatani
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Ohkubo
authors.forename: Masaki
authors.initials: M
authors.lastname: Ihara
authors.forename: Hajime
authors.initials: H
authors.lastname: Morishima
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D016466:CHO Cells; D020013:Calcium Signaling / Q000187:drug effects; D006224:Cricetinae; D015195:Drug Design; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D064446:Orexin Receptors; D000068797:Orexins; D017433:Protein Structure, Secondary; D051381:Rats; D043562:Receptors, G-Protein-Coupled; D018013:Receptors, Neuropeptide / Q000819:agonists* / Q000378:metabolism
chemical_list: C000596229:HCRT protein, human; D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D064446:Orexin Receptors; D000068797:Orexins; D043562:Receptors, G-Protein-Coupled; D018013:Receptors, Neuropeptide