Opioid binding profile of morphiceptin, Tyr-MIF-1 and dynorphin-related peptides in rat brain membranes.
Opioid properties of several morphiceptin- (Tyr-Pro-Phe-Pro-NH2), Tyr-MIF-1 (Tyr-Pro-Leu-Gly-NH2) and dynorphin-derivatives were characterized in rat brain in vitro receptor binding assay and in electrically stimulated longitudinal muscle strip preparation of guinea pig ileum. In the case of morphiceptin-related peptides, an excellent correlation was found between the [3H]-naloxone binding displacement data and the agonist potencies determined in the bioassay. The "turning point' was the C-terminal amidation in the tri- and tetrapeptide pairs in both series. Tyr-MIF-1 derivatives showed weak affinity in the opioid receptor binding assay and none of them had any remarkable effect in the bioassay either as agonist or antagonist. The dynorphin A(1-10)-peptides modified at positions 5 and 8 retained their affinity with Pro5-, Pro8-, and Ala8-substituents, whereas some loss of affinity was observed in the case of Gly8-Dyn A(1-10).
Sartania
N
N
Institute of Biochemistry, Hungarian Academy of Sciences, Szeged, Hungary.
Benyhe
S
S
Magyar
A
A
Rónai
A Z
AZ
Medzihradszky
K
K
Borsodi
A
A
D000700:Analgesics / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D001665:Binding Sites; D001667:Binding, Competitive; D001921:Brain / Q000378:metabolism* / Q000648:ultrastructure; D002462:Cell Membrane / Q000378:metabolism; D004399:Dynorphins / Q000737:chemistry / Q000378:metabolism*; D004723:Endorphins / Q000737:chemistry / Q000378:metabolism*; D006168:Guinea Pigs; D007082:Ileum / Q000378:metabolism; D009075:MSH Release-Inhibiting Hormone / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D008297:Male; D009132:Muscles / Q000378:metabolism; D009270:Naloxone / Q000032:analysis / Q000378:metabolism; D009292:Narcotic Antagonists / Q000032:analysis / Q000378:metabolism; D009842:Oligopeptides / Q000737:chemistry / Q000378:metabolism; D018847:Opioid Peptides / Q000737:chemistry / Q000378:metabolism*; D011869:Radioligand Assay; D051381:Rats; D011957:Receptors, Opioid / Q000819:agonists / Q000378:metabolism*; D013329:Structure-Activity Relationship; D014316:Tritium
D000700:Analgesics; D004723:Endorphins; D009292:Narcotic Antagonists; D009842:Oligopeptides; D018847:Opioid Peptides; D011957:Receptors, Opioid; D014316:Tritium; D009270:Naloxone; D004399:Dynorphins; C036930:tyrosyl-prolyl-leucyl-glycinamide; D009075:MSH Release-Inhibiting Hormone; C028889:morphiceptin