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.
Takahashi
M
M
Department of Food Science and Technology, Faculty of Agriculture, Kyoto University, Japan.
Moriguchi
S
S
Yoshikawa
M
M
Sasaki
R
R
D000276:Adjuvants, Immunologic; D000328:Adult; D000418:Albumins / Q000737:chemistry*; D000595:Amino Acid Sequence; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001921:Brain / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D004745:Enkephalins / Q000378:metabolism / Q000494:pharmacology; D006168:Guinea Pigs; D006801:Humans; D007082:Ileum / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology*; D009504:Neutrophils / Q000187:drug effects / Q000502:physiology*; D009842:Oligopeptides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D012275:Oryza / Q000737:chemistry*; D010446:Peptide Fragments / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D010587:Phagocytosis / Q000187:drug effects; D010940:Plant Proteins / Q000302:isolation & purification / Q000494:pharmacology; D011869:Radioligand Assay; D051381:Rats; D017450:Receptors, Opioid, mu / Q000187:drug effects / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013481:Superoxides / Q000097:blood; D013779:Tetrodotoxin / Q000494:pharmacology; D014357:Trypsin
D000276:Adjuvants, Immunologic; D000418:Albumins; D004745:Enkephalins; D009842:Oligopeptides; D010446:Peptide Fragments; D010940:Plant Proteins; D017450:Receptors, Opioid, mu; C091249:oryzatensin; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D013481:Superoxides; D013779:Tetrodotoxin; D001285:Atropine; D014357:Trypsin