title: Delta opioid peptides derived from plant proteins.
abstract: Opioid peptides showing selectivity for delta receptor have been isolated from enzymatic digests of plant proteins. Five peptides were derived from wheat gluten, and named gluten exorphins A5, A4, B5, B4 and C. Two opioid peptides were also released from spinach ribulose-bisphosphate-carboxylase/oxygenase (Rubisco), and named rubiscolins-5 and -6. Among them, gluten exorphin 5A (Gly-Tyr-Tyr-Pro-Thr) and rubiscolin 6 (Tyr-Pro-Leu-Asp-Leu-Phe) improved learning performance in step-through type passive avoidance test after post-training oral administration in mice at doses of 300 mg/kg and 100 mg/kg, respectively, which are smaller than those required for antinociceptive activity.
authors.affiliation: Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan. yosikawa@kais.kyoto-u.ac.jp
authors.forename: M
authors.initials: M
authors.lastname: Yoshikawa
authors.forename: M
authors.initials: M
authors.lastname: Takahashi
authors.forename: S
authors.initials: S
authors.lastname: Yang
mesh_terms: D000701:Analgesics, Opioid / Q000737:chemistry / Q000494:pharmacology; D000818:Animals; D014151:Anti-Anxiety Agents / Q000737:chemistry / Q000494:pharmacology; D005983:Glutens / Q000737:chemistry; D008568:Memory / Q000187:drug effects; D051379:Mice; D018847:Opioid Peptides / Q000737:chemistry* / Q000494:pharmacology*; D010446:Peptide Fragments / Q000737:chemistry / Q000494:pharmacology; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology; D010940:Plant Proteins / Q000737:chemistry*; D051381:Rats; D017465:Receptors, Opioid, delta / Q000819:agonists; D012273:Ribulose-Bisphosphate Carboxylase / Q000737:chemistry / Q000494:pharmacology
chemical_list: D000701:Analgesics, Opioid; D014151:Anti-Anxiety Agents; D018847:Opioid Peptides; D010446:Peptide Fragments; D010455:Peptides; D010940:Plant Proteins; D017465:Receptors, Opioid, delta; C443992:rubiscolin 5; C443993:rubiscolin 6; C019178:exorphins; D005983:Glutens; D012273:Ribulose-Bisphosphate Carboxylase