Soymorphins, novel mu opioid peptides derived from soy beta-conglycinin beta-subunit, have anxiolytic activities.
Based on the amino acid sequence YPFV found in the soy beta-conglycinin beta-subunit, which is common to an opioid peptide human beta-casomorphin-4, peptides YPFVV, YPFVVN, and YPFVVNA were synthesized according to their primary structure. On guinea pig ileum (GPI) assay, they showed opioid activity (IC50 = 6.0, 9.2 and 13 microM respectively) more potent than human beta-casomorphins, and were named soymorphins-5, -6, and -7, respectively. Their opioid activities on mouse vas deferens (MVD) assay were less potent than on GPI assay, suggesting that they are selective for the mu opioid receptor. Human beta-casomorphin-4 and soymorphin-5 were released from the soy 7S fraction (beta-conglycinin) by the action of gastrointestinal proteases. Soymorphins-5, -6, and -7 had anxiolytic activities after oral administration at doses of 10-30 mg/kg in the elevated plus-maze test in mice.
Ohinata
Kousaku
K
Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Japan.
Agui
Shun
S
Yoshikawa
Masaaki
M
D000284:Administration, Oral; D000595:Amino Acid Sequence; D000818:Animals; D014151:Anti-Anxiety Agents / Q000737:chemistry / Q000494:pharmacology*; D001522:Behavior, Animal / Q000187:drug effects; D001681:Biological Assay; D004305:Dose-Response Relationship, Drug; D004723:Endorphins / Q000737:chemistry / Q000494:pharmacology*; D006168:Guinea Pigs; D006801:Humans; D007082:Ileum / Q000187:drug effects; D020128:Inhibitory Concentration 50; D007931:Leucyl Aminopeptidase / Q000494:pharmacology; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D018847:Opioid Peptides / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D010196:Pancreatic Elastase / Q000494:pharmacology; D011869:Radioligand Assay; D014649:Vas Deferens / Q000187:drug effects
D014151:Anti-Anxiety Agents; D004723:Endorphins; D018847:Opioid Peptides; C021968:beta-casomorphins; D007931:Leucyl Aminopeptidase; D010196:Pancreatic Elastase