title: Structure-activity relationship of rubiscolins as delta opioid peptides.
abstract: To study the structure-activity relationship of rubiscolins (YPLDLF and YPLDL), delta opioid peptides derived from the spinach Rubisco, we substituted the amino acid residues and evaluated their activities by mouse vas deferens (MVD) and guinea pig ileum (GPI) assays as well as receptor affinity. Replacement of Leu(3) with Ile and Met in rubiscolin-6 potentiated the delta opioid activity by about four times in MVD assay. Asp(4) cannot be replaced by Ala, Glu or His. The original Leu(5) was optimal, while substitution of Phe(6) with Val potentiated its delta opioid activity by more than 10 times. The most potent derivative we obtained was YPMDLV, which was nearly 20 times more potent than rubiscolin-6 in MVD assay. The derivatives thus obtained showed higher delta receptor affinity and more potent antinociceptive activity than rubiscolins.
authors.affiliation: Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Japan.
authors.forename: Shuzhang
authors.initials: S
authors.lastname: Yang
authors.forename: Soushi
authors.initials: S
authors.lastname: Sonoda
authors.forename: Liping
authors.initials: L
authors.lastname: Chen
authors.forename: Masaaki
authors.initials: M
authors.lastname: Yoshikawa
mesh_terms: D000700:Analgesics / Q000494:pharmacology; D000818:Animals; D006168:Guinea Pigs; D020128:Inhibitory Concentration 50; D007532:Isoleucine / Q000737:chemistry; D007930:Leucine / Q000737:chemistry; D008297:Male; D008715:Methionine / Q000737:chemistry; D010452:Peptide Biosynthesis; D010446:Peptide Fragments / Q000737:chemistry* / Q000502:physiology*; D010455:Peptides / Q000737:chemistry; D017465:Receptors, Opioid, delta / Q000737:chemistry*; D012273:Ribulose-Bisphosphate Carboxylase / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology*; D018724:Spinacia oleracea / Q000378:metabolism; D013329:Structure-Activity Relationship; D013997:Time Factors
chemical_list: D000700:Analgesics; D010446:Peptide Fragments; D010455:Peptides; D017465:Receptors, Opioid, delta; C443993:rubiscolin 6; D007532:Isoleucine; D008715:Methionine; D012273:Ribulose-Bisphosphate Carboxylase; D007930:Leucine