Topochemical analysis of morphiceptin and dermorphin bioactivities.
To elucidate the topochemical requirements for bioactivities of morphiceptin (Tyr-Pro-Phe-Pro-NH2) and dermorphin (Tyr-D-Ala-Phe-Gly-Tyr-Pro-Ser-NH2), we have designed and synthesized two diastereomers Tyr-(L and D)-(NMe)Ala-Phe-D-Pro-NH2. Both the analogs display high activities in the guinea pig ileum assay. The only difference in the composition of these two diastereomers arises from the chirality at residue 2. The high mu-receptor activities are attributed to structures where the Tyr1-L-(NMe)Ala2 amide bond assumes a cis configuration while the Tyr1-D-(NMe)Ala2 amide bond assumes a trans configuration. Accessible space studied for the second residues of these molecules confirms the fact that the L-(NMe)Ala2 analog belongs to the morphiceptin family of opioids while the D-(NMe)Ala2 analog belongs to the dermorphin class of opioids. The similarity in the spacial array of the analogs explains their high mu-receptor activities and indicates that they are likely recognized at the same opioid receptor.
Yamazaki
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Department of Chemistry, University of California, San Diego, La Jolla 92093.
Ro
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Goodman
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D000595:Amino Acid Sequence; D000818:Animals; D004723:Endorphins / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects / Q000502:physiology; D008297:Male; D051379:Mice; D008968:Molecular Conformation; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D018847:Opioid Peptides; D011957:Receptors, Opioid / Q000187:drug effects / Q000502:physiology; D017465:Receptors, Opioid, delta; D017450:Receptors, Opioid, mu; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D014649:Vas Deferens / Q000187:drug effects / Q000502:physiology
D004723:Endorphins; D009842:Oligopeptides; D018847:Opioid Peptides; D011957:Receptors, Opioid; D017465:Receptors, Opioid, delta; D017450:Receptors, Opioid, mu; C030058:dermorphin; C028889:morphiceptin