Morphinomimetic activity of synthetic fragments of beta-lipotropin and analogs.
In the myenteric plexus-longitudinal muscle bioassay, beta-endorphin, i.e., beta-lipotropin (beta-LPH)-[61-91], has a potency of 450 with confidence limits of 281-966 when Met5-enkephalin is used as a reference standard with a potency of 100. The primary amide and the ethylamide of Met5-enkephalin have potencies statistically overlapping with that of beta-endorphin. The primary amide of alpha-endorphin has twice the potency of the free acid form of alpha-endorphin. An intact NH2-terminal tyrosine is not necessary for full intrinsic activity. The shortest fragment of beta-LPH with morphinomimetic activity is beta-LPH-[61-64].
D000595:Amino Acid Sequence; D000818:Animals; D001681:Biological Assay; D006168:Guinea Pigs; D009842:Oligopeptides / Q000494:pharmacology*; D010446:Peptide Fragments / Q000494:pharmacology; D013329:Structure-Activity Relationship; D008083:beta-Lipotropin / Q000494:pharmacology*
D009842:Oligopeptides; D010446:Peptide Fragments; D008083:beta-Lipotropin