Binding characteristics of dermorphin, and [dermorphin1-7]-beta c-endorphin in rat brain membranes.
Dermorphin and a camel beta-endorphin (beta c-EP) analog in which residues 1-7 correspond to the dermorphin sequence ([Dermorphin1-7]-beta c-EP) have been investigated with respect to their receptor binding characteristics using human and camel beta-EP as reference peptides. Tritiated dihydromorphine, [D-Ala2, D-Leu5]-enkephalin, ethylketocyclazocine and human beta-endorphin were used as primary ligands in the rat brain membrane preparation for radioreceptor assay. Camel beta-endorphin was the most potent peptide in all experiments. [Dermorphin1-7]-beta c-EP is significantly less potent towards 3H-ethylketocyclazocine and 3H-[D-Ala2, D-Leu5]-enkephalin but is as potent towards 3H-dihydromorphine and 3H-human beta-endorphin. Dermorphin itself weakly displaces tritiated dihydromorphine, [D-Ala2, D-Leu5]-enkephalin and ethylketocyclazocine (potency relative to camel beta-EP, 1-4%) but it is more potent (9%) in competition with tritiated human beta-endorphin. Dermorphin and the [Dermorphin-1-7]-beta c-EP appear to interact preferentially with mu opiate receptors.
Westphal
M
M
Hammonds
R G
RG
Li
C H
CH
D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000378:metabolism*; D004723:Endorphins / Q000378:metabolism*; D008566:Membranes / Q000378:metabolism; D009842:Oligopeptides / Q000378:metabolism*; D018847:Opioid Peptides; D051381:Rats; D011957:Receptors, Opioid / Q000378:metabolism*; D013329:Structure-Activity Relationship; D001615:beta-Endorphin
D004723:Endorphins; D009842:Oligopeptides; D018847:Opioid Peptides; D011957:Receptors, Opioid; C030058:dermorphin; D001615:beta-Endorphin