Opioid peptides derived from wheat gluten: Their isolation and characterization

• Published in: FEBS letters 1992-01, Vol.296 (1), p.107-111
• Main Authors: Fukudome, Shin-ichi, Yoshikawa, Masaaki
• Format: Article
• Language: English
• Subjects: [D-Ala2, D-Leu5]enkephalin; [D-Ala2,MePhe4,Glycol5]enkephalin; Amino Acid Sequence; Aminoacids, peptides. Hormones. Neuropeptides; Analytical, structural and metabolic biochemistry; Biological and medical sciences; characterization; Chromatography, High Pressure Liquid; Chymotrypsin; DADLE; DAGO; EKC; ethylketocyclazocine; Exorphin; Fundamental and applied biological sciences. Psychology; Gluten; Glutenin; Glutens - analogs & derivatives; Glutens - chemistry; GPI; guinea pig ileum; high-performance liquid chromatography; HPLC; isolation; Molecular Sequence Data; mouse vas deferens; MVD; octadecyl silica; ODS; Opioid peptide; opioid peptides; Pepsin A; Peptides - genetics; Peptides - isolation & purification; Peptides - metabolism; Proteins; Radioligand Assay; Receptors, Opioid - metabolism; Receptors, Opioid, delta; Sequence Homology, Nucleic Acid; Substrate Specificity; TFA; Thermolysin; trifluoroacetic acid; Triticum; Triticum - chemistry; Trypsin; Wheat
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/0014-5793(92)80414-C

Four opioid peptides were isolated from the enzymatic digest of wheat gluten. Their structures were Gly-Tyr-Tyr-Pro-Thr, Gly-Tyr-Tyr-Pro,Tyr-Gly-Gly-Trp-Leu and Tyr-Gly-Gly-Trp, which were named gluten exorphins A5, A4, B5 and B4, respectively. The gluten exorphin A5 sequence was found at 15 sites in the primary structure of the high molecular weight glutenin and was highly specific for δ-receptors. The structure—activity relationships of gluten exorphins A were unique in that the presence of Gly at their N-termini increased their activities. Gluten exorphin B5, which corresponds to [Trp 4,Leu 5]enkephalin, showed the most potent activity among these peptides. Its IC 50 values were 0.05 μM and 0.017 μM, respectively, on the GPI and the MVD assays.