enkephalin--ala(2)-mephe(4)-gly(5)- has been researched along with oryzatensin* in 2 studies
2 other study(ies) available for enkephalin--ala(2)-mephe(4)-gly(5)- and oryzatensin
| Article | Year |
|---|---|
Identification of casoxin C, an ileum-contracting peptide derived from bovine kappa-casein, as an agonist for C3a receptors.
Casoxin C (Tyr-Ile-Pro-Ile-Gln-Tyr-Val-Leu-Ser-Arg) is a bioactive peptide that was isolated from a tryptic digest of bovine kappa-casein as an anti-opioid peptide in longitudinal strips of guinea pig ileum. Casoxin C also evokes contraction of the ileal strips, and we found that this process was biphasic with rapid and slow components. The contractile profile was very similar to that of human complement C3a(70-77), which is the COOH-terminal octapeptide of C3a and has, although less potent, qualitatively the same biological activities as C3a. Casoxin C also has homology with C3a(70-77). The rapid contraction was mediated by histamine release and the slow contraction was mediated by a prostaglandin E2-like substance, judging from the effects of various pharmacological inhibitors and antagonists on the ileal contraction. Casoxin C had affinity for C3a receptors (IC50 = 40 microM) in the radioreceptor assay. In addition, casoxin C showed phagocyte-stimulating activities. Casoxin C is therefore the first milk-derived peptide identified, that acts through complement C3a receptors. Topics: Amino Acid Sequence; Animals; Caseins; Cattle; Complement C3a; Dinoprostone; Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; Enkephalins; Guinea Pigs; Humans; Ileum; Membrane Proteins; Muscle Contraction; Muscle, Smooth; Oligopeptides; Peptide Fragments; Phagocytosis; Protein Binding; Pyrilamine; Receptors, Complement; Receptors, Opioid, mu; Sequence Homology, Amino Acid; Structure-Activity Relationship | 1997 |
Isolation and characterization of oryzatensin: a novel bioactive peptide with ileum-contracting and immunomodulating activities derived from rice albumin.
A novel bioactive peptide was isolated from the tryptic digest of rice soluble protein based on ileum-contracting and anti-opioid activities in the isolated guinea pig ileum. The structure of the peptide was Gly-Tyr-Pro-Met-Tyr-Pro-Leu-Pro-Arg, and it was named oryzatensin. Oryzatensin showed a biphasic ileum-contraction, which was characterized by a rapid contraction followed by a slower one. The latter was mediated by the cholinergic nervous system because it was inhibited by tetrodotoxin and atropine. Although oryzatensin showed weak affinity for mu-opioid receptors, the apparent anti-opioid activity seemed to be associated with the slower contraction. On the other hand, oryzatensin showed phagocytosis-promoting activity for human polymorphonuclear leukocytes and augmented the production of superoxide anion by human peripheral leukocytes. Topics: Adjuvants, Immunologic; Adult; Albumins; Amino Acid Sequence; Animals; Atropine; Brain; Cell Membrane; Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; Enkephalins; Guinea Pigs; Humans; Ileum; In Vitro Techniques; Molecular Sequence Data; Muscle Contraction; Muscle, Smooth; Neutrophils; Oligopeptides; Oryza; Peptide Fragments; Phagocytosis; Plant Proteins; Radioligand Assay; Rats; Receptors, Opioid, mu; Sequence Homology, Amino Acid; Superoxides; Tetrodotoxin; Trypsin | 1994 |